diff --git a/cogl/Makefile.am b/cogl/Makefile.am
index 31baa21d6..b3d53831d 100644
--- a/cogl/Makefile.am
+++ b/cogl/Makefile.am
@@ -2,7 +2,7 @@ include $(top_srcdir)/build/autotools/Makefile.am.silent
NULL =
-SUBDIRS = driver
+SUBDIRS = driver tesselator
BUILT_SOURCES =
EXTRA_DIST =
@@ -159,7 +159,10 @@ include $(top_srcdir)/build/autotools/Makefile.am.enums
noinst_LTLIBRARIES = libclutter-cogl.la
-libclutter_cogl_la_LIBADD = -lm $(CLUTTER_LIBS) $(top_builddir)/clutter/cogl/cogl/driver/$(COGL_DRIVER)/libclutter-cogl-driver.la
+libclutter_cogl_la_LIBADD = \
+ -lm $(CLUTTER_LIBS) \
+ $(top_builddir)/clutter/cogl/cogl/driver/$(COGL_DRIVER)/libclutter-cogl-driver.la \
+ $(top_builddir)/clutter/cogl/cogl/tesselator/libtesselator.la
libclutter_cogl_la_SOURCES = $(BUILT_SOURCES) $(cogl_sources_c)
diff --git a/cogl/tesselator/GL/glu.h b/cogl/tesselator/GL/glu.h
new file mode 100644
index 000000000..c6c847b58
--- /dev/null
+++ b/cogl/tesselator/GL/glu.h
@@ -0,0 +1,26 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2010 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see .
+ *
+ */
+
+/* This is just a wrapper to use our simplified version of glu.h so
+ that the tesselator code can still #include */
+
+#include "../tesselator.h"
diff --git a/cogl/tesselator/Makefile.am b/cogl/tesselator/Makefile.am
new file mode 100644
index 000000000..c7445063d
--- /dev/null
+++ b/cogl/tesselator/Makefile.am
@@ -0,0 +1,41 @@
+AM_CFLAGS = $(CLUTTER_CFLAGS) $(MAINTAINER_CFLAGS)
+
+noinst_LTLIBRARIES = libtesselator.la
+
+INCLUDES = \
+ -I$(top_srcdir)/clutter/cogl \
+ -I$(srcdir)/winsys \
+ -I$(srcdir)/driver/$(COGL_DRIVER) \
+ -I$(srcdir)/clutter/cogl/cogl/tesselator \
+ -I$(top_builddir)/clutter/cogl
+
+libtesselator_la_SOURCES = \
+ dict-list.h \
+ dict.c \
+ dict.h \
+ geom.c \
+ geom.h \
+ gluos.h \
+ memalloc.h \
+ mesh.c \
+ mesh.h \
+ normal.c \
+ normal.h \
+ priorityq-heap.h \
+ priorityq-sort.h \
+ priorityq.c \
+ priorityq.h \
+ render.c \
+ render.h \
+ sweep.c \
+ sweep.h \
+ tess.c \
+ tess.h \
+ tesselator.h \
+ tessmono.c \
+ tessmono.h \
+ GL/glu.h
+
+EXTRA_DIST = \
+ README \
+ priorityq-heap.c
diff --git a/cogl/tesselator/README b/cogl/tesselator/README
new file mode 100644
index 000000000..66a6011e2
--- /dev/null
+++ b/cogl/tesselator/README
@@ -0,0 +1,446 @@
+/*
+*/
+
+General Polygon Tesselation
+---------------------------
+
+ This note describes a tesselator for polygons consisting of one or
+ more closed contours. It is backward-compatible with the current
+ OpenGL Utilities tesselator, and is intended to replace it. Here is
+ a summary of the major differences:
+
+ - input contours can be intersecting, self-intersecting, or degenerate.
+
+ - supports a choice of several winding rules for determining which parts
+ of the polygon are on the "interior". This makes it possible to do
+ CSG operations on polygons.
+
+ - boundary extraction: instead of tesselating the polygon, returns a
+ set of closed contours which separate the interior from the exterior.
+
+ - returns the output as a small number of triangle fans and strips,
+ rather than a list of independent triangles (when possible).
+
+ - output is available as an explicit mesh (a quad-edge structure),
+ in addition to the normal callback interface.
+
+ - the algorithm used is extremely robust.
+
+
+The interface
+-------------
+
+ The tesselator state is maintained in a "tesselator object".
+ These are allocated and destroyed using
+
+ GLUtesselator *gluNewTess( void );
+ void gluDeleteTess( GLUtesselator *tess );
+
+ Several tesselator objects may be used simultaneously.
+
+ Inputs
+ ------
+
+ The input contours are specified with the following routines:
+
+ void gluTessBeginPolygon( GLUtesselator *tess );
+ void gluTessBeginContour( GLUtesselator *tess );
+ void gluTessVertex( GLUtesselator *tess, GLUcoord coords[3], void *data );
+ void gluTessEndContour( GLUtesselator *tess );
+ void gluTessEndPolygon( GLUtesselator *tess );
+
+ Within each BeginPolygon/EndPolygon pair, there can be zero or more
+ calls to BeginContour/EndContour. Within each contour, there are zero
+ or more calls to gluTessVertex(). The vertices specify a closed
+ contour (the last vertex of each contour is automatically linked to
+ the first).
+
+ "coords" give the coordinates of the vertex in 3-space. For useful
+ results, all vertices should lie in some plane, since the vertices
+ are projected onto a plane before tesselation. "data" is a pointer
+ to a user-defined vertex structure, which typically contains other
+ information such as color, texture coordinates, normal, etc. It is
+ used to refer to the vertex during rendering.
+
+ The library can be compiled in single- or double-precision; the type
+ GLUcoord represents either "float" or "double" accordingly. The GLU
+ version will be available in double-precision only. Compile with
+ GLU_TESS_API_FLOAT defined to get the single-precision version.
+
+ When EndPolygon is called, the tesselation algorithm determines
+ which regions are interior to the given contours, according to one
+ of several "winding rules" described below. The interior regions
+ are then tesselated, and the output is provided as callbacks.
+
+
+ Rendering Callbacks
+ -------------------
+
+ Callbacks are specified by the client using
+
+ void gluTessCallback( GLUtesselator *tess, GLenum which, void (*fn)());
+
+ If "fn" is NULL, any previously defined callback is discarded.
+
+ The callbacks used to provide output are: /* which == */
+
+ void begin( GLenum type ); /* GLU_TESS_BEGIN */
+ void edgeFlag( GLboolean flag ); /* GLU_TESS_EDGE_FLAG */
+ void vertex( void *data ); /* GLU_TESS_VERTEX */
+ void end( void ); /* GLU_TESS_END */
+
+ Any of the callbacks may be left undefined; if so, the corresponding
+ information will not be supplied during rendering.
+
+ The "begin" callback indicates the start of a primitive; type is one
+ of GL_TRIANGLE_STRIP, GL_TRIANGLE_FAN, or GL_TRIANGLES (but see the
+ notes on "boundary extraction" below).
+
+ It is followed by any number of "vertex" callbacks, which supply the
+ vertices in the same order as expected by the corresponding glBegin()
+ call. After the last vertex of a given primitive, there is a callback
+ to "end".
+
+ If the "edgeFlag" callback is provided, no triangle fans or strips
+ will be used. When edgeFlag is called, if "flag" is GL_TRUE then each
+ vertex which follows begins an edge which lies on the polygon boundary
+ (ie. an edge which separates an interior region from an exterior one).
+ If "flag" is GL_FALSE, each vertex which follows begins an edge which lies
+ in the polygon interior. "edgeFlag" will be called before the first
+ call to "vertex".
+
+ Other Callbacks
+ ---------------
+
+ void mesh( GLUmesh *mesh ); /* GLU_TESS_MESH */
+
+ - Returns an explicit mesh, represented using the quad-edge structure
+ (Guibas/Stolfi '85). Other implementations of this interface might
+ use a different mesh structure, so this is available only only as an
+ SGI extension. When the mesh is no longer needed, it should be freed
+ using
+
+ void gluDeleteMesh( GLUmesh *mesh );
+
+ There is a brief description of this data structure in the include
+ file "mesh.h". For the full details, see L. Guibas and J. Stolfi,
+ Primitives for the manipulation of general subdivisions and the
+ computation of Voronoi diagrams, ACM Transactions on Graphics,
+ 4(2):74-123, April 1985. For an introduction, see the course notes
+ for CS348a, "Mathematical Foundations of Computer Graphics",
+ available at the Stanford bookstore (and taught during the fall
+ quarter).
+
+ void error( GLenum errno ); /* GLU_TESS_ERROR */
+
+ - errno is one of GLU_TESS_MISSING_BEGIN_POLYGON,
+ GLU_TESS_MISSING_END_POLYGON,
+ GLU_TESS_MISSING_BEGIN_CONTOUR,
+ GLU_TESS_MISSING_END_CONTOUR,
+ GLU_TESS_COORD_TOO_LARGE,
+ GLU_TESS_NEED_COMBINE_CALLBACK
+
+ The first four are obvious. The interface recovers from these
+ errors by inserting the missing call(s).
+
+ GLU_TESS_COORD_TOO_LARGE says that some vertex coordinate exceeded
+ the predefined constant GLU_TESS_MAX_COORD in absolute value, and
+ that the value has been clamped. (Coordinate values must be small
+ enough so that two can be multiplied together without overflow.)
+
+ GLU_TESS_NEED_COMBINE_CALLBACK says that the algorithm detected an
+ intersection between two edges in the input data, and the "combine"
+ callback (below) was not provided. No output will be generated.
+
+
+ void combine( GLUcoord coords[3], void *data[4], /* GLU_TESS_COMBINE */
+ GLUcoord weight[4], void **outData );
+
+ - When the algorithm detects an intersection, or wishes to merge
+ features, it needs to create a new vertex. The vertex is defined
+ as a linear combination of up to 4 existing vertices, referenced
+ by data[0..3]. The coefficients of the linear combination are
+ given by weight[0..3]; these weights always sum to 1.0. All vertex
+ pointers are valid even when some of the weights are zero.
+ "coords" gives the location of the new vertex.
+
+ The user must allocate another vertex, interpolate parameters
+ using "data" and "weights", and return the new vertex pointer in
+ "outData". This handle is supplied during rendering callbacks.
+ For example, if the polygon lies in an arbitrary plane in 3-space,
+ and we associate a color with each vertex, the combine callback might
+ look like this:
+
+ void myCombine( GLUcoord coords[3], VERTEX *d[4],
+ GLUcoord w[4], VERTEX **dataOut )
+ {
+ VERTEX *new = new_vertex();
+
+ new->x = coords[0];
+ new->y = coords[1];
+ new->z = coords[2];
+ new->r = w[0]*d[0]->r + w[1]*d[1]->r + w[2]*d[2]->r + w[3]*d[3]->r;
+ new->g = w[0]*d[0]->g + w[1]*d[1]->g + w[2]*d[2]->g + w[3]*d[3]->g;
+ new->b = w[0]*d[0]->b + w[1]*d[1]->b + w[2]*d[2]->b + w[3]*d[3]->b;
+ new->a = w[0]*d[0]->a + w[1]*d[1]->a + w[2]*d[2]->a + w[3]*d[3]->a;
+ *dataOut = new;
+ }
+
+ If the algorithm detects an intersection, then the "combine" callback
+ must be defined, and must write a non-NULL pointer into "dataOut".
+ Otherwise the GLU_TESS_NEED_COMBINE_CALLBACK error occurs, and no
+ output is generated. This is the only error that can occur during
+ tesselation and rendering.
+
+
+ Control over Tesselation
+ ------------------------
+
+ void gluTessProperty( GLUtesselator *tess, GLenum which, GLUcoord value );
+
+ Properties defined:
+
+ - GLU_TESS_WINDING_RULE. Possible values:
+
+ GLU_TESS_WINDING_ODD
+ GLU_TESS_WINDING_NONZERO
+ GLU_TESS_WINDING_POSITIVE
+ GLU_TESS_WINDING_NEGATIVE
+ GLU_TESS_WINDING_ABS_GEQ_TWO
+
+ The input contours parition the plane into regions. A winding
+ rule determines which of these regions are inside the polygon.
+
+ For a single contour C, the winding number of a point x is simply
+ the signed number of revolutions we make around x as we travel
+ once around C (where CCW is positive). When there are several
+ contours, the individual winding numbers are summed. This
+ procedure associates a signed integer value with each point x in
+ the plane. Note that the winding number is the same for all
+ points in a single region.
+
+ The winding rule classifies a region as "inside" if its winding
+ number belongs to the chosen category (odd, nonzero, positive,
+ negative, or absolute value of at least two). The current GLU
+ tesselator implements the "odd" rule. The "nonzero" rule is another
+ common way to define the interior. The other three rules are
+ useful for polygon CSG operations (see below).
+
+ - GLU_TESS_BOUNDARY_ONLY. Values: TRUE (non-zero) or FALSE (zero).
+
+ If TRUE, returns a set of closed contours which separate the
+ polygon interior and exterior (rather than a tesselation).
+ Exterior contours are oriented CCW with respect to the normal,
+ interior contours are oriented CW. The GLU_TESS_BEGIN callback
+ uses the type GL_LINE_LOOP for each contour.
+
+ - GLU_TESS_TOLERANCE. Value: a real number between 0.0 and 1.0.
+
+ This specifies a tolerance for merging features to reduce the size
+ of the output. For example, two vertices which are very close to
+ each other might be replaced by a single vertex. The tolerance
+ is multiplied by the largest coordinate magnitude of any input vertex;
+ this specifies the maximum distance that any feature can move as the
+ result of a single merge operation. If a single feature takes part
+ in several merge operations, the total distance moved could be larger.
+
+ Feature merging is completely optional; the tolerance is only a hint.
+ The implementation is free to merge in some cases and not in others,
+ or to never merge features at all. The default tolerance is zero.
+
+ The current implementation merges vertices only if they are exactly
+ coincident, regardless of the current tolerance. A vertex is
+ spliced into an edge only if the implementation is unable to
+ distinguish which side of the edge the vertex lies on.
+ Two edges are merged only when both endpoints are identical.
+
+
+ void gluTessNormal( GLUtesselator *tess,
+ GLUcoord x, GLUcoord y, GLUcoord z )
+
+ - Lets the user supply the polygon normal, if known. All input data
+ is projected into a plane perpendicular to the normal before
+ tesselation. All output triangles are oriented CCW with
+ respect to the normal (CW orientation can be obtained by
+ reversing the sign of the supplied normal). For example, if
+ you know that all polygons lie in the x-y plane, call
+ "gluTessNormal(tess, 0.0, 0.0, 1.0)" before rendering any polygons.
+
+ - If the supplied normal is (0,0,0) (the default value), the
+ normal is determined as follows. The direction of the normal,
+ up to its sign, is found by fitting a plane to the vertices,
+ without regard to how the vertices are connected. It is
+ expected that the input data lies approximately in plane;
+ otherwise projection perpendicular to the computed normal may
+ substantially change the geometry. The sign of the normal is
+ chosen so that the sum of the signed areas of all input contours
+ is non-negative (where a CCW contour has positive area).
+
+ - The supplied normal persists until it is changed by another
+ call to gluTessNormal.
+
+
+ Backward compatibility with the GLU tesselator
+ ----------------------------------------------
+
+ The preferred interface is the one described above. The following
+ routines are obsolete, and are provided only for backward compatibility:
+
+ typedef GLUtesselator GLUtriangulatorObj; /* obsolete name */
+
+ void gluBeginPolygon( GLUtesselator *tess );
+ void gluNextContour( GLUtesselator *tess, GLenum type );
+ void gluEndPolygon( GLUtesselator *tess );
+
+ "type" is one of GLU_EXTERIOR, GLU_INTERIOR, GLU_CCW, GLU_CW, or
+ GLU_UNKNOWN. It is ignored by the current GLU tesselator.
+
+ GLU_BEGIN, GLU_VERTEX, GLU_END, GLU_ERROR, and GLU_EDGE_FLAG are defined
+ as synonyms for GLU_TESS_BEGIN, GLU_TESS_VERTEX, GLU_TESS_END,
+ GLU_TESS_ERROR, and GLU_TESS_EDGE_FLAG.
+
+
+Polygon CSG operations
+----------------------
+
+ The features of the tesselator make it easy to find the union, difference,
+ or intersection of several polygons.
+
+ First, assume that each polygon is defined so that the winding number
+ is 0 for each exterior region, and 1 for each interior region. Under
+ this model, CCW contours define the outer boundary of the polygon, and
+ CW contours define holes. Contours may be nested, but a nested
+ contour must be oriented oppositely from the contour that contains it.
+
+ If the original polygons do not satisfy this description, they can be
+ converted to this form by first running the tesselator with the
+ GLU_TESS_BOUNDARY_ONLY property turned on. This returns a list of
+ contours satisfying the restriction above. By allocating two
+ tesselator objects, the callbacks from one tesselator can be fed
+ directly to the input of another.
+
+ Given two or more polygons of the form above, CSG operations can be
+ implemented as follows:
+
+ Union
+ Draw all the input contours as a single polygon. The winding number
+ of each resulting region is the number of original polygons
+ which cover it. The union can be extracted using the
+ GLU_TESS_WINDING_NONZERO or GLU_TESS_WINDING_POSITIVE winding rules.
+ Note that with the nonzero rule, we would get the same result if
+ all contour orientations were reversed.
+
+ Intersection (two polygons at a time only)
+ Draw a single polygon using the contours from both input polygons.
+ Extract the result using GLU_TESS_WINDING_ABS_GEQ_TWO. (Since this
+ winding rule looks at the absolute value, reversing all contour
+ orientations does not change the result.)
+
+ Difference
+
+ Suppose we want to compute A \ (B union C union D). Draw a single
+ polygon consisting of the unmodified contours from A, followed by
+ the contours of B,C,D with the vertex order reversed (this changes
+ the winding number of the interior regions to -1). To extract the
+ result, use the GLU_TESS_WINDING_POSITIVE rule.
+
+ If B,C,D are the result of a GLU_TESS_BOUNDARY_ONLY call, an
+ alternative to reversing the vertex order is to reverse the sign of
+ the supplied normal. For example in the x-y plane, call
+ gluTessNormal( tess, 0.0, 0.0, -1.0 ).
+
+
+Performance
+-----------
+
+ The tesselator is not intended for immediate-mode rendering; when
+ possible the output should be cached in a user structure or display
+ list. General polygon tesselation is an inherently difficult problem,
+ especially given the goal of extreme robustness.
+
+ The implementation makes an effort to output a small number of fans
+ and strips; this should improve the rendering performance when the
+ output is used in a display list.
+
+ Single-contour input polygons are first tested to see whether they can
+ be rendered as a triangle fan with respect to the first vertex (to
+ avoid running the full decomposition algorithm on convex polygons).
+ Non-convex polygons may be rendered by this "fast path" as well, if
+ the algorithm gets lucky in its choice of a starting vertex.
+
+ For best performance follow these guidelines:
+
+ - supply the polygon normal, if available, using gluTessNormal().
+ This represents about 10% of the computation time. For example,
+ if all polygons lie in the x-y plane, use gluTessNormal(tess,0,0,1).
+
+ - render many polygons using the same tesselator object, rather than
+ allocating a new tesselator for each one. (In a multi-threaded,
+ multi-processor environment you may get better performance using
+ several tesselators.)
+
+
+Comparison with the GLU tesselator
+----------------------------------
+
+ On polygons which make it through the "fast path", the tesselator is
+ 3 to 5 times faster than the GLU tesselator.
+
+ On polygons which don't make it through the fast path (but which don't
+ have self-intersections or degeneracies), it is about 2 times slower.
+
+ On polygons with self-intersections or degeneraces, there is nothing
+ to compare against.
+
+ The new tesselator generates many more fans and strips, reducing the
+ number of vertices that need to be sent to the hardware.
+
+ Key to the statistics:
+
+ vert number of input vertices on all contours
+ cntr number of input contours
+ tri number of triangles in all output primitives
+ strip number of triangle strips
+ fan number of triangle fans
+ ind number of independent triangles
+ ms number of milliseconds for tesselation
+ (on a 150MHz R4400 Indy)
+
+ Convex polygon examples:
+
+New: 3 vert, 1 cntr, 1 tri, 0 strip, 0 fan, 1 ind, 0.0459 ms
+Old: 3 vert, 1 cntr, 1 tri, 0 strip, 0 fan, 1 ind, 0.149 ms
+New: 4 vert, 1 cntr, 2 tri, 0 strip, 1 fan, 0 ind, 0.0459 ms
+Old: 4 vert, 1 cntr, 2 tri, 0 strip, 0 fan, 2 ind, 0.161 ms
+New: 36 vert, 1 cntr, 34 tri, 0 strip, 1 fan, 0 ind, 0.153 ms
+Old: 36 vert, 1 cntr, 34 tri, 0 strip, 0 fan, 34 ind, 0.621 ms
+
+ Concave single-contour polygons:
+
+New: 5 vert, 1 cntr, 3 tri, 0 strip, 1 fan, 0 ind, 0.052 ms
+Old: 5 vert, 1 cntr, 3 tri, 0 strip, 0 fan, 3 ind, 0.252 ms
+New: 19 vert, 1 cntr, 17 tri, 2 strip, 2 fan, 1 ind, 0.911 ms
+Old: 19 vert, 1 cntr, 17 tri, 0 strip, 0 fan, 17 ind, 0.529 ms
+New: 151 vert, 1 cntr, 149 tri, 13 strip, 18 fan, 3 ind, 6.82 ms
+Old: 151 vert, 1 cntr, 149 tri, 0 strip, 3 fan, 143 ind, 2.7 ms
+New: 574 vert, 1 cntr, 572 tri, 59 strip, 54 fan, 11 ind, 26.6 ms
+Old: 574 vert, 1 cntr, 572 tri, 0 strip, 31 fan, 499 ind, 12.4 ms
+
+ Multiple contours, but no intersections:
+
+New: 7 vert, 2 cntr, 7 tri, 1 strip, 0 fan, 0 ind, 0.527 ms
+Old: 7 vert, 2 cntr, 7 tri, 0 strip, 0 fan, 7 ind, 0.274 ms
+New: 81 vert, 6 cntr, 89 tri, 9 strip, 7 fan, 6 ind, 3.88 ms
+Old: 81 vert, 6 cntr, 89 tri, 0 strip, 13 fan, 61 ind, 2.2 ms
+New: 391 vert, 19 cntr, 413 tri, 37 strip, 32 fan, 26 ind, 20.2 ms
+Old: 391 vert, 19 cntr, 413 tri, 0 strip, 25 fan, 363 ind, 8.68 ms
+
+ Self-intersecting and degenerate examples:
+
+Bowtie: 4 vert, 1 cntr, 2 tri, 0 strip, 0 fan, 2 ind, 0.483 ms
+Star: 5 vert, 1 cntr, 5 tri, 0 strip, 0 fan, 5 ind, 0.91 ms
+Random: 24 vert, 7 cntr, 46 tri, 2 strip, 12 fan, 7 ind, 5.32 ms
+Font: 333 vert, 2 cntr, 331 tri, 32 strip, 16 fan, 3 ind, 14.1 ms
+: 167 vert, 35 cntr, 254 tri, 8 strip, 56 fan, 52 ind, 46.3 ms
+: 78 vert, 1 cntr, 2675 tri, 148 strip, 207 fan, 180 ind, 243 ms
+: 12480 vert, 2 cntr, 12478 tri, 736 strip,1275 fan, 5 ind, 1010 ms
diff --git a/cogl/tesselator/dict-list.h b/cogl/tesselator/dict-list.h
new file mode 100644
index 000000000..11331a76e
--- /dev/null
+++ b/cogl/tesselator/dict-list.h
@@ -0,0 +1,100 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __dict_list_h_
+#define __dict_list_h_
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define DictKey DictListKey
+#define Dict DictList
+#define DictNode DictListNode
+
+#define dictNewDict(frame,leq) __gl_dictListNewDict(frame,leq)
+#define dictDeleteDict(dict) __gl_dictListDeleteDict(dict)
+
+#define dictSearch(dict,key) __gl_dictListSearch(dict,key)
+#define dictInsert(dict,key) __gl_dictListInsert(dict,key)
+#define dictInsertBefore(dict,node,key) __gl_dictListInsertBefore(dict,node,key)
+#define dictDelete(dict,node) __gl_dictListDelete(dict,node)
+
+#define dictKey(n) __gl_dictListKey(n)
+#define dictSucc(n) __gl_dictListSucc(n)
+#define dictPred(n) __gl_dictListPred(n)
+#define dictMin(d) __gl_dictListMin(d)
+#define dictMax(d) __gl_dictListMax(d)
+
+
+
+typedef void *DictKey;
+typedef struct Dict Dict;
+typedef struct DictNode DictNode;
+
+Dict *dictNewDict(
+ void *frame,
+ int (*leq)(void *frame, DictKey key1, DictKey key2) );
+
+void dictDeleteDict( Dict *dict );
+
+/* Search returns the node with the smallest key greater than or equal
+ * to the given key. If there is no such key, returns a node whose
+ * key is NULL. Similarly, Succ(Max(d)) has a NULL key, etc.
+ */
+DictNode *dictSearch( Dict *dict, DictKey key );
+DictNode *dictInsertBefore( Dict *dict, DictNode *node, DictKey key );
+void dictDelete( Dict *dict, DictNode *node );
+
+#define __gl_dictListKey(n) ((n)->key)
+#define __gl_dictListSucc(n) ((n)->next)
+#define __gl_dictListPred(n) ((n)->prev)
+#define __gl_dictListMin(d) ((d)->head.next)
+#define __gl_dictListMax(d) ((d)->head.prev)
+#define __gl_dictListInsert(d,k) (dictInsertBefore((d),&(d)->head,(k)))
+
+
+/*** Private data structures ***/
+
+struct DictNode {
+ DictKey key;
+ DictNode *next;
+ DictNode *prev;
+};
+
+struct Dict {
+ DictNode head;
+ void *frame;
+ int (*leq)(void *frame, DictKey key1, DictKey key2);
+};
+
+#endif
diff --git a/cogl/tesselator/dict.c b/cogl/tesselator/dict.c
new file mode 100644
index 000000000..49d4f759e
--- /dev/null
+++ b/cogl/tesselator/dict.c
@@ -0,0 +1,111 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include
+#include "dict-list.h"
+#include "memalloc.h"
+
+/* really __gl_dictListNewDict */
+Dict *dictNewDict( void *frame,
+ int (*leq)(void *frame, DictKey key1, DictKey key2) )
+{
+ Dict *dict = (Dict *) memAlloc( sizeof( Dict ));
+ DictNode *head;
+
+ if (dict == NULL) return NULL;
+
+ head = &dict->head;
+
+ head->key = NULL;
+ head->next = head;
+ head->prev = head;
+
+ dict->frame = frame;
+ dict->leq = leq;
+
+ return dict;
+}
+
+/* really __gl_dictListDeleteDict */
+void dictDeleteDict( Dict *dict )
+{
+ DictNode *node, *next;
+
+ for( node = dict->head.next; node != &dict->head; node = next ) {
+ next = node->next;
+ memFree( node );
+ }
+ memFree( dict );
+}
+
+/* really __gl_dictListInsertBefore */
+DictNode *dictInsertBefore( Dict *dict, DictNode *node, DictKey key )
+{
+ DictNode *newNode;
+
+ do {
+ node = node->prev;
+ } while( node->key != NULL && ! (*dict->leq)(dict->frame, node->key, key));
+
+ newNode = (DictNode *) memAlloc( sizeof( DictNode ));
+ if (newNode == NULL) return NULL;
+
+ newNode->key = key;
+ newNode->next = node->next;
+ node->next->prev = newNode;
+ newNode->prev = node;
+ node->next = newNode;
+
+ return newNode;
+}
+
+/* really __gl_dictListDelete */
+void dictDelete( Dict *dict, DictNode *node ) /*ARGSUSED*/
+{
+ node->next->prev = node->prev;
+ node->prev->next = node->next;
+ memFree( node );
+}
+
+/* really __gl_dictListSearch */
+DictNode *dictSearch( Dict *dict, DictKey key )
+{
+ DictNode *node = &dict->head;
+
+ do {
+ node = node->next;
+ } while( node->key != NULL && ! (*dict->leq)(dict->frame, key, node->key));
+
+ return node;
+}
diff --git a/cogl/tesselator/dict.h b/cogl/tesselator/dict.h
new file mode 100644
index 000000000..11331a76e
--- /dev/null
+++ b/cogl/tesselator/dict.h
@@ -0,0 +1,100 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __dict_list_h_
+#define __dict_list_h_
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define DictKey DictListKey
+#define Dict DictList
+#define DictNode DictListNode
+
+#define dictNewDict(frame,leq) __gl_dictListNewDict(frame,leq)
+#define dictDeleteDict(dict) __gl_dictListDeleteDict(dict)
+
+#define dictSearch(dict,key) __gl_dictListSearch(dict,key)
+#define dictInsert(dict,key) __gl_dictListInsert(dict,key)
+#define dictInsertBefore(dict,node,key) __gl_dictListInsertBefore(dict,node,key)
+#define dictDelete(dict,node) __gl_dictListDelete(dict,node)
+
+#define dictKey(n) __gl_dictListKey(n)
+#define dictSucc(n) __gl_dictListSucc(n)
+#define dictPred(n) __gl_dictListPred(n)
+#define dictMin(d) __gl_dictListMin(d)
+#define dictMax(d) __gl_dictListMax(d)
+
+
+
+typedef void *DictKey;
+typedef struct Dict Dict;
+typedef struct DictNode DictNode;
+
+Dict *dictNewDict(
+ void *frame,
+ int (*leq)(void *frame, DictKey key1, DictKey key2) );
+
+void dictDeleteDict( Dict *dict );
+
+/* Search returns the node with the smallest key greater than or equal
+ * to the given key. If there is no such key, returns a node whose
+ * key is NULL. Similarly, Succ(Max(d)) has a NULL key, etc.
+ */
+DictNode *dictSearch( Dict *dict, DictKey key );
+DictNode *dictInsertBefore( Dict *dict, DictNode *node, DictKey key );
+void dictDelete( Dict *dict, DictNode *node );
+
+#define __gl_dictListKey(n) ((n)->key)
+#define __gl_dictListSucc(n) ((n)->next)
+#define __gl_dictListPred(n) ((n)->prev)
+#define __gl_dictListMin(d) ((d)->head.next)
+#define __gl_dictListMax(d) ((d)->head.prev)
+#define __gl_dictListInsert(d,k) (dictInsertBefore((d),&(d)->head,(k)))
+
+
+/*** Private data structures ***/
+
+struct DictNode {
+ DictKey key;
+ DictNode *next;
+ DictNode *prev;
+};
+
+struct Dict {
+ DictNode head;
+ void *frame;
+ int (*leq)(void *frame, DictKey key1, DictKey key2);
+};
+
+#endif
diff --git a/cogl/tesselator/geom.c b/cogl/tesselator/geom.c
new file mode 100644
index 000000000..7d3b8d8a6
--- /dev/null
+++ b/cogl/tesselator/geom.c
@@ -0,0 +1,264 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include "mesh.h"
+#include "geom.h"
+
+int __gl_vertLeq( GLUvertex *u, GLUvertex *v )
+{
+ /* Returns TRUE if u is lexicographically <= v. */
+
+ return VertLeq( u, v );
+}
+
+GLdouble __gl_edgeEval( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+ /* Given three vertices u,v,w such that VertLeq(u,v) && VertLeq(v,w),
+ * evaluates the t-coord of the edge uw at the s-coord of the vertex v.
+ * Returns v->t - (uw)(v->s), ie. the signed distance from uw to v.
+ * If uw is vertical (and thus passes thru v), the result is zero.
+ *
+ * The calculation is extremely accurate and stable, even when v
+ * is very close to u or w. In particular if we set v->t = 0 and
+ * let r be the negated result (this evaluates (uw)(v->s)), then
+ * r is guaranteed to satisfy MIN(u->t,w->t) <= r <= MAX(u->t,w->t).
+ */
+ GLdouble gapL, gapR;
+
+ assert( VertLeq( u, v ) && VertLeq( v, w ));
+
+ gapL = v->s - u->s;
+ gapR = w->s - v->s;
+
+ if( gapL + gapR > 0 ) {
+ if( gapL < gapR ) {
+ return (v->t - u->t) + (u->t - w->t) * (gapL / (gapL + gapR));
+ } else {
+ return (v->t - w->t) + (w->t - u->t) * (gapR / (gapL + gapR));
+ }
+ }
+ /* vertical line */
+ return 0;
+}
+
+GLdouble __gl_edgeSign( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+ /* Returns a number whose sign matches EdgeEval(u,v,w) but which
+ * is cheaper to evaluate. Returns > 0, == 0 , or < 0
+ * as v is above, on, or below the edge uw.
+ */
+ GLdouble gapL, gapR;
+
+ assert( VertLeq( u, v ) && VertLeq( v, w ));
+
+ gapL = v->s - u->s;
+ gapR = w->s - v->s;
+
+ if( gapL + gapR > 0 ) {
+ return (v->t - w->t) * gapL + (v->t - u->t) * gapR;
+ }
+ /* vertical line */
+ return 0;
+}
+
+
+/***********************************************************************
+ * Define versions of EdgeSign, EdgeEval with s and t transposed.
+ */
+
+GLdouble __gl_transEval( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+ /* Given three vertices u,v,w such that TransLeq(u,v) && TransLeq(v,w),
+ * evaluates the t-coord of the edge uw at the s-coord of the vertex v.
+ * Returns v->s - (uw)(v->t), ie. the signed distance from uw to v.
+ * If uw is vertical (and thus passes thru v), the result is zero.
+ *
+ * The calculation is extremely accurate and stable, even when v
+ * is very close to u or w. In particular if we set v->s = 0 and
+ * let r be the negated result (this evaluates (uw)(v->t)), then
+ * r is guaranteed to satisfy MIN(u->s,w->s) <= r <= MAX(u->s,w->s).
+ */
+ GLdouble gapL, gapR;
+
+ assert( TransLeq( u, v ) && TransLeq( v, w ));
+
+ gapL = v->t - u->t;
+ gapR = w->t - v->t;
+
+ if( gapL + gapR > 0 ) {
+ if( gapL < gapR ) {
+ return (v->s - u->s) + (u->s - w->s) * (gapL / (gapL + gapR));
+ } else {
+ return (v->s - w->s) + (w->s - u->s) * (gapR / (gapL + gapR));
+ }
+ }
+ /* vertical line */
+ return 0;
+}
+
+GLdouble __gl_transSign( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+ /* Returns a number whose sign matches TransEval(u,v,w) but which
+ * is cheaper to evaluate. Returns > 0, == 0 , or < 0
+ * as v is above, on, or below the edge uw.
+ */
+ GLdouble gapL, gapR;
+
+ assert( TransLeq( u, v ) && TransLeq( v, w ));
+
+ gapL = v->t - u->t;
+ gapR = w->t - v->t;
+
+ if( gapL + gapR > 0 ) {
+ return (v->s - w->s) * gapL + (v->s - u->s) * gapR;
+ }
+ /* vertical line */
+ return 0;
+}
+
+
+int __gl_vertCCW( GLUvertex *u, GLUvertex *v, GLUvertex *w )
+{
+ /* For almost-degenerate situations, the results are not reliable.
+ * Unless the floating-point arithmetic can be performed without
+ * rounding errors, *any* implementation will give incorrect results
+ * on some degenerate inputs, so the client must have some way to
+ * handle this situation.
+ */
+ return (u->s*(v->t - w->t) + v->s*(w->t - u->t) + w->s*(u->t - v->t)) >= 0;
+}
+
+/* Given parameters a,x,b,y returns the value (b*x+a*y)/(a+b),
+ * or (x+y)/2 if a==b==0. It requires that a,b >= 0, and enforces
+ * this in the rare case that one argument is slightly negative.
+ * The implementation is extremely stable numerically.
+ * In particular it guarantees that the result r satisfies
+ * MIN(x,y) <= r <= MAX(x,y), and the results are very accurate
+ * even when a and b differ greatly in magnitude.
+ */
+#define RealInterpolate(a,x,b,y) \
+ (a = (a < 0) ? 0 : a, b = (b < 0) ? 0 : b, \
+ ((a <= b) ? ((b == 0) ? ((x+y) / 2) \
+ : (x + (y-x) * (a/(a+b)))) \
+ : (y + (x-y) * (b/(a+b)))))
+
+#ifndef FOR_TRITE_TEST_PROGRAM
+#define Interpolate(a,x,b,y) RealInterpolate(a,x,b,y)
+#else
+
+/* Claim: the ONLY property the sweep algorithm relies on is that
+ * MIN(x,y) <= r <= MAX(x,y). This is a nasty way to test that.
+ */
+#include
+extern int RandomInterpolate;
+
+GLdouble Interpolate( GLdouble a, GLdouble x, GLdouble b, GLdouble y)
+{
+printf("*********************%d\n",RandomInterpolate);
+ if( RandomInterpolate ) {
+ a = 1.2 * drand48() - 0.1;
+ a = (a < 0) ? 0 : ((a > 1) ? 1 : a);
+ b = 1.0 - a;
+ }
+ return RealInterpolate(a,x,b,y);
+}
+
+#endif
+
+#define Swap(a,b) if (1) { GLUvertex *t = a; a = b; b = t; } else
+
+void __gl_edgeIntersect( GLUvertex *o1, GLUvertex *d1,
+ GLUvertex *o2, GLUvertex *d2,
+ GLUvertex *v )
+/* Given edges (o1,d1) and (o2,d2), compute their point of intersection.
+ * The computed point is guaranteed to lie in the intersection of the
+ * bounding rectangles defined by each edge.
+ */
+{
+ GLdouble z1, z2;
+
+ /* This is certainly not the most efficient way to find the intersection
+ * of two line segments, but it is very numerically stable.
+ *
+ * Strategy: find the two middle vertices in the VertLeq ordering,
+ * and interpolate the intersection s-value from these. Then repeat
+ * using the TransLeq ordering to find the intersection t-value.
+ */
+
+ if( ! VertLeq( o1, d1 )) { Swap( o1, d1 ); }
+ if( ! VertLeq( o2, d2 )) { Swap( o2, d2 ); }
+ if( ! VertLeq( o1, o2 )) { Swap( o1, o2 ); Swap( d1, d2 ); }
+
+ if( ! VertLeq( o2, d1 )) {
+ /* Technically, no intersection -- do our best */
+ v->s = (o2->s + d1->s) / 2;
+ } else if( VertLeq( d1, d2 )) {
+ /* Interpolate between o2 and d1 */
+ z1 = EdgeEval( o1, o2, d1 );
+ z2 = EdgeEval( o2, d1, d2 );
+ if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+ v->s = Interpolate( z1, o2->s, z2, d1->s );
+ } else {
+ /* Interpolate between o2 and d2 */
+ z1 = EdgeSign( o1, o2, d1 );
+ z2 = -EdgeSign( o1, d2, d1 );
+ if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+ v->s = Interpolate( z1, o2->s, z2, d2->s );
+ }
+
+ /* Now repeat the process for t */
+
+ if( ! TransLeq( o1, d1 )) { Swap( o1, d1 ); }
+ if( ! TransLeq( o2, d2 )) { Swap( o2, d2 ); }
+ if( ! TransLeq( o1, o2 )) { Swap( o1, o2 ); Swap( d1, d2 ); }
+
+ if( ! TransLeq( o2, d1 )) {
+ /* Technically, no intersection -- do our best */
+ v->t = (o2->t + d1->t) / 2;
+ } else if( TransLeq( d1, d2 )) {
+ /* Interpolate between o2 and d1 */
+ z1 = TransEval( o1, o2, d1 );
+ z2 = TransEval( o2, d1, d2 );
+ if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+ v->t = Interpolate( z1, o2->t, z2, d1->t );
+ } else {
+ /* Interpolate between o2 and d2 */
+ z1 = TransSign( o1, o2, d1 );
+ z2 = -TransSign( o1, d2, d1 );
+ if( z1+z2 < 0 ) { z1 = -z1; z2 = -z2; }
+ v->t = Interpolate( z1, o2->t, z2, d2->t );
+ }
+}
diff --git a/cogl/tesselator/geom.h b/cogl/tesselator/geom.h
new file mode 100644
index 000000000..5cb76c7d1
--- /dev/null
+++ b/cogl/tesselator/geom.h
@@ -0,0 +1,84 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __geom_h_
+#define __geom_h_
+
+#include "mesh.h"
+
+#ifdef NO_BRANCH_CONDITIONS
+/* MIPS architecture has special instructions to evaluate boolean
+ * conditions -- more efficient than branching, IF you can get the
+ * compiler to generate the right instructions (SGI compiler doesn't)
+ */
+#define VertEq(u,v) (((u)->s == (v)->s) & ((u)->t == (v)->t))
+#define VertLeq(u,v) (((u)->s < (v)->s) | \
+ ((u)->s == (v)->s & (u)->t <= (v)->t))
+#else
+#define VertEq(u,v) ((u)->s == (v)->s && (u)->t == (v)->t)
+#define VertLeq(u,v) (((u)->s < (v)->s) || \
+ ((u)->s == (v)->s && (u)->t <= (v)->t))
+#endif
+
+#define EdgeEval(u,v,w) __gl_edgeEval(u,v,w)
+#define EdgeSign(u,v,w) __gl_edgeSign(u,v,w)
+
+/* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */
+
+#define TransLeq(u,v) (((u)->t < (v)->t) || \
+ ((u)->t == (v)->t && (u)->s <= (v)->s))
+#define TransEval(u,v,w) __gl_transEval(u,v,w)
+#define TransSign(u,v,w) __gl_transSign(u,v,w)
+
+
+#define EdgeGoesLeft(e) VertLeq( (e)->Dst, (e)->Org )
+#define EdgeGoesRight(e) VertLeq( (e)->Org, (e)->Dst )
+
+#undef ABS
+#define ABS(x) ((x) < 0 ? -(x) : (x))
+#define VertL1dist(u,v) (ABS(u->s - v->s) + ABS(u->t - v->t))
+
+#define VertCCW(u,v,w) __gl_vertCCW(u,v,w)
+
+int __gl_vertLeq( GLUvertex *u, GLUvertex *v );
+GLdouble __gl_edgeEval( GLUvertex *u, GLUvertex *v, GLUvertex *w );
+GLdouble __gl_edgeSign( GLUvertex *u, GLUvertex *v, GLUvertex *w );
+GLdouble __gl_transEval( GLUvertex *u, GLUvertex *v, GLUvertex *w );
+GLdouble __gl_transSign( GLUvertex *u, GLUvertex *v, GLUvertex *w );
+int __gl_vertCCW( GLUvertex *u, GLUvertex *v, GLUvertex *w );
+void __gl_edgeIntersect( GLUvertex *o1, GLUvertex *d1,
+ GLUvertex *o2, GLUvertex *d2,
+ GLUvertex *v );
+
+#endif
diff --git a/cogl/tesselator/gluos.h b/cogl/tesselator/gluos.h
new file mode 100644
index 000000000..d6c3ae998
--- /dev/null
+++ b/cogl/tesselator/gluos.h
@@ -0,0 +1 @@
+/* This is a stub header to avoid having to change tess.c */
diff --git a/cogl/tesselator/memalloc.h b/cogl/tesselator/memalloc.h
new file mode 100644
index 000000000..0293e1557
--- /dev/null
+++ b/cogl/tesselator/memalloc.h
@@ -0,0 +1,42 @@
+/*
+ * Cogl
+ *
+ * An object oriented GL/GLES Abstraction/Utility Layer
+ *
+ * Copyright (C) 2010 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see .
+ *
+ *
+ */
+
+/* This is a simple replacement for memalloc from the SGI tesselator
+ code to force it to use glib's allocation instead */
+
+#ifndef __MEMALLOC_H__
+#define __MEMALLOC_H__
+
+#include
+
+#define memRealloc g_realloc
+#define memAlloc g_malloc
+#define memFree g_free
+#define memInit(x) 1
+
+/* tess.c defines TRUE and FALSE itself unconditionally so we need to
+ undefine it from the glib headers */
+#undef TRUE
+#undef FALSE
+
+#endif /* __MEMALLOC_H__ */
diff --git a/cogl/tesselator/mesh.c b/cogl/tesselator/mesh.c
new file mode 100644
index 000000000..95f87cdc9
--- /dev/null
+++ b/cogl/tesselator/mesh.c
@@ -0,0 +1,794 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include
+#include "mesh.h"
+#include "memalloc.h"
+
+#define TRUE 1
+#define FALSE 0
+
+static GLUvertex *allocVertex()
+{
+ return (GLUvertex *)memAlloc( sizeof( GLUvertex ));
+}
+
+static GLUface *allocFace()
+{
+ return (GLUface *)memAlloc( sizeof( GLUface ));
+}
+
+/************************ Utility Routines ************************/
+
+/* Allocate and free half-edges in pairs for efficiency.
+ * The *only* place that should use this fact is allocation/free.
+ */
+typedef struct { GLUhalfEdge e, eSym; } EdgePair;
+
+/* MakeEdge creates a new pair of half-edges which form their own loop.
+ * No vertex or face structures are allocated, but these must be assigned
+ * before the current edge operation is completed.
+ */
+static GLUhalfEdge *MakeEdge( GLUhalfEdge *eNext )
+{
+ GLUhalfEdge *e;
+ GLUhalfEdge *eSym;
+ GLUhalfEdge *ePrev;
+ EdgePair *pair = (EdgePair *)memAlloc( sizeof( EdgePair ));
+ if (pair == NULL) return NULL;
+
+ e = &pair->e;
+ eSym = &pair->eSym;
+
+ /* Make sure eNext points to the first edge of the edge pair */
+ if( eNext->Sym < eNext ) { eNext = eNext->Sym; }
+
+ /* Insert in circular doubly-linked list before eNext.
+ * Note that the prev pointer is stored in Sym->next.
+ */
+ ePrev = eNext->Sym->next;
+ eSym->next = ePrev;
+ ePrev->Sym->next = e;
+ e->next = eNext;
+ eNext->Sym->next = eSym;
+
+ e->Sym = eSym;
+ e->Onext = e;
+ e->Lnext = eSym;
+ e->Org = NULL;
+ e->Lface = NULL;
+ e->winding = 0;
+ e->activeRegion = NULL;
+
+ eSym->Sym = e;
+ eSym->Onext = eSym;
+ eSym->Lnext = e;
+ eSym->Org = NULL;
+ eSym->Lface = NULL;
+ eSym->winding = 0;
+ eSym->activeRegion = NULL;
+
+ return e;
+}
+
+/* Splice( a, b ) is best described by the Guibas/Stolfi paper or the
+ * CS348a notes (see mesh.h). Basically it modifies the mesh so that
+ * a->Onext and b->Onext are exchanged. This can have various effects
+ * depending on whether a and b belong to different face or vertex rings.
+ * For more explanation see __gl_meshSplice() below.
+ */
+static void Splice( GLUhalfEdge *a, GLUhalfEdge *b )
+{
+ GLUhalfEdge *aOnext = a->Onext;
+ GLUhalfEdge *bOnext = b->Onext;
+
+ aOnext->Sym->Lnext = b;
+ bOnext->Sym->Lnext = a;
+ a->Onext = bOnext;
+ b->Onext = aOnext;
+}
+
+/* MakeVertex( newVertex, eOrig, vNext ) attaches a new vertex and makes it the
+ * origin of all edges in the vertex loop to which eOrig belongs. "vNext" gives
+ * a place to insert the new vertex in the global vertex list. We insert
+ * the new vertex *before* vNext so that algorithms which walk the vertex
+ * list will not see the newly created vertices.
+ */
+static void MakeVertex( GLUvertex *newVertex,
+ GLUhalfEdge *eOrig, GLUvertex *vNext )
+{
+ GLUhalfEdge *e;
+ GLUvertex *vPrev;
+ GLUvertex *vNew = newVertex;
+
+ assert(vNew != NULL);
+
+ /* insert in circular doubly-linked list before vNext */
+ vPrev = vNext->prev;
+ vNew->prev = vPrev;
+ vPrev->next = vNew;
+ vNew->next = vNext;
+ vNext->prev = vNew;
+
+ vNew->anEdge = eOrig;
+ vNew->data = NULL;
+ /* leave coords, s, t undefined */
+
+ /* fix other edges on this vertex loop */
+ e = eOrig;
+ do {
+ e->Org = vNew;
+ e = e->Onext;
+ } while( e != eOrig );
+}
+
+/* MakeFace( newFace, eOrig, fNext ) attaches a new face and makes it the left
+ * face of all edges in the face loop to which eOrig belongs. "fNext" gives
+ * a place to insert the new face in the global face list. We insert
+ * the new face *before* fNext so that algorithms which walk the face
+ * list will not see the newly created faces.
+ */
+static void MakeFace( GLUface *newFace, GLUhalfEdge *eOrig, GLUface *fNext )
+{
+ GLUhalfEdge *e;
+ GLUface *fPrev;
+ GLUface *fNew = newFace;
+
+ assert(fNew != NULL);
+
+ /* insert in circular doubly-linked list before fNext */
+ fPrev = fNext->prev;
+ fNew->prev = fPrev;
+ fPrev->next = fNew;
+ fNew->next = fNext;
+ fNext->prev = fNew;
+
+ fNew->anEdge = eOrig;
+ fNew->data = NULL;
+ fNew->trail = NULL;
+ fNew->marked = FALSE;
+
+ /* The new face is marked "inside" if the old one was. This is a
+ * convenience for the common case where a face has been split in two.
+ */
+ fNew->inside = fNext->inside;
+
+ /* fix other edges on this face loop */
+ e = eOrig;
+ do {
+ e->Lface = fNew;
+ e = e->Lnext;
+ } while( e != eOrig );
+}
+
+/* KillEdge( eDel ) destroys an edge (the half-edges eDel and eDel->Sym),
+ * and removes from the global edge list.
+ */
+static void KillEdge( GLUhalfEdge *eDel )
+{
+ GLUhalfEdge *ePrev, *eNext;
+
+ /* Half-edges are allocated in pairs, see EdgePair above */
+ if( eDel->Sym < eDel ) { eDel = eDel->Sym; }
+
+ /* delete from circular doubly-linked list */
+ eNext = eDel->next;
+ ePrev = eDel->Sym->next;
+ eNext->Sym->next = ePrev;
+ ePrev->Sym->next = eNext;
+
+ memFree( eDel );
+}
+
+
+/* KillVertex( vDel ) destroys a vertex and removes it from the global
+ * vertex list. It updates the vertex loop to point to a given new vertex.
+ */
+static void KillVertex( GLUvertex *vDel, GLUvertex *newOrg )
+{
+ GLUhalfEdge *e, *eStart = vDel->anEdge;
+ GLUvertex *vPrev, *vNext;
+
+ /* change the origin of all affected edges */
+ e = eStart;
+ do {
+ e->Org = newOrg;
+ e = e->Onext;
+ } while( e != eStart );
+
+ /* delete from circular doubly-linked list */
+ vPrev = vDel->prev;
+ vNext = vDel->next;
+ vNext->prev = vPrev;
+ vPrev->next = vNext;
+
+ memFree( vDel );
+}
+
+/* KillFace( fDel ) destroys a face and removes it from the global face
+ * list. It updates the face loop to point to a given new face.
+ */
+static void KillFace( GLUface *fDel, GLUface *newLface )
+{
+ GLUhalfEdge *e, *eStart = fDel->anEdge;
+ GLUface *fPrev, *fNext;
+
+ /* change the left face of all affected edges */
+ e = eStart;
+ do {
+ e->Lface = newLface;
+ e = e->Lnext;
+ } while( e != eStart );
+
+ /* delete from circular doubly-linked list */
+ fPrev = fDel->prev;
+ fNext = fDel->next;
+ fNext->prev = fPrev;
+ fPrev->next = fNext;
+
+ memFree( fDel );
+}
+
+
+/****************** Basic Edge Operations **********************/
+
+/* __gl_meshMakeEdge creates one edge, two vertices, and a loop (face).
+ * The loop consists of the two new half-edges.
+ */
+GLUhalfEdge *__gl_meshMakeEdge( GLUmesh *mesh )
+{
+ GLUvertex *newVertex1= allocVertex();
+ GLUvertex *newVertex2= allocVertex();
+ GLUface *newFace= allocFace();
+ GLUhalfEdge *e;
+
+ /* if any one is null then all get freed */
+ if (newVertex1 == NULL || newVertex2 == NULL || newFace == NULL) {
+ if (newVertex1 != NULL) memFree(newVertex1);
+ if (newVertex2 != NULL) memFree(newVertex2);
+ if (newFace != NULL) memFree(newFace);
+ return NULL;
+ }
+
+ e = MakeEdge( &mesh->eHead );
+ if (e == NULL) {
+ memFree(newVertex1);
+ memFree(newVertex2);
+ memFree(newFace);
+ return NULL;
+ }
+
+ MakeVertex( newVertex1, e, &mesh->vHead );
+ MakeVertex( newVertex2, e->Sym, &mesh->vHead );
+ MakeFace( newFace, e, &mesh->fHead );
+ return e;
+}
+
+
+/* __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the
+ * mesh connectivity and topology. It changes the mesh so that
+ * eOrg->Onext <- OLD( eDst->Onext )
+ * eDst->Onext <- OLD( eOrg->Onext )
+ * where OLD(...) means the value before the meshSplice operation.
+ *
+ * This can have two effects on the vertex structure:
+ * - if eOrg->Org != eDst->Org, the two vertices are merged together
+ * - if eOrg->Org == eDst->Org, the origin is split into two vertices
+ * In both cases, eDst->Org is changed and eOrg->Org is untouched.
+ *
+ * Similarly (and independently) for the face structure,
+ * - if eOrg->Lface == eDst->Lface, one loop is split into two
+ * - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one
+ * In both cases, eDst->Lface is changed and eOrg->Lface is unaffected.
+ *
+ * Some special cases:
+ * If eDst == eOrg, the operation has no effect.
+ * If eDst == eOrg->Lnext, the new face will have a single edge.
+ * If eDst == eOrg->Lprev, the old face will have a single edge.
+ * If eDst == eOrg->Onext, the new vertex will have a single edge.
+ * If eDst == eOrg->Oprev, the old vertex will have a single edge.
+ */
+int __gl_meshSplice( GLUhalfEdge *eOrg, GLUhalfEdge *eDst )
+{
+ int joiningLoops = FALSE;
+ int joiningVertices = FALSE;
+
+ if( eOrg == eDst ) return 1;
+
+ if( eDst->Org != eOrg->Org ) {
+ /* We are merging two disjoint vertices -- destroy eDst->Org */
+ joiningVertices = TRUE;
+ KillVertex( eDst->Org, eOrg->Org );
+ }
+ if( eDst->Lface != eOrg->Lface ) {
+ /* We are connecting two disjoint loops -- destroy eDst->Lface */
+ joiningLoops = TRUE;
+ KillFace( eDst->Lface, eOrg->Lface );
+ }
+
+ /* Change the edge structure */
+ Splice( eDst, eOrg );
+
+ if( ! joiningVertices ) {
+ GLUvertex *newVertex= allocVertex();
+ if (newVertex == NULL) return 0;
+
+ /* We split one vertex into two -- the new vertex is eDst->Org.
+ * Make sure the old vertex points to a valid half-edge.
+ */
+ MakeVertex( newVertex, eDst, eOrg->Org );
+ eOrg->Org->anEdge = eOrg;
+ }
+ if( ! joiningLoops ) {
+ GLUface *newFace= allocFace();
+ if (newFace == NULL) return 0;
+
+ /* We split one loop into two -- the new loop is eDst->Lface.
+ * Make sure the old face points to a valid half-edge.
+ */
+ MakeFace( newFace, eDst, eOrg->Lface );
+ eOrg->Lface->anEdge = eOrg;
+ }
+
+ return 1;
+}
+
+
+/* __gl_meshDelete( eDel ) removes the edge eDel. There are several cases:
+ * if (eDel->Lface != eDel->Rface), we join two loops into one; the loop
+ * eDel->Lface is deleted. Otherwise, we are splitting one loop into two;
+ * the newly created loop will contain eDel->Dst. If the deletion of eDel
+ * would create isolated vertices, those are deleted as well.
+ *
+ * This function could be implemented as two calls to __gl_meshSplice
+ * plus a few calls to memFree, but this would allocate and delete
+ * unnecessary vertices and faces.
+ */
+int __gl_meshDelete( GLUhalfEdge *eDel )
+{
+ GLUhalfEdge *eDelSym = eDel->Sym;
+ int joiningLoops = FALSE;
+
+ /* First step: disconnect the origin vertex eDel->Org. We make all
+ * changes to get a consistent mesh in this "intermediate" state.
+ */
+ if( eDel->Lface != eDel->Rface ) {
+ /* We are joining two loops into one -- remove the left face */
+ joiningLoops = TRUE;
+ KillFace( eDel->Lface, eDel->Rface );
+ }
+
+ if( eDel->Onext == eDel ) {
+ KillVertex( eDel->Org, NULL );
+ } else {
+ /* Make sure that eDel->Org and eDel->Rface point to valid half-edges */
+ eDel->Rface->anEdge = eDel->Oprev;
+ eDel->Org->anEdge = eDel->Onext;
+
+ Splice( eDel, eDel->Oprev );
+ if( ! joiningLoops ) {
+ GLUface *newFace= allocFace();
+ if (newFace == NULL) return 0;
+
+ /* We are splitting one loop into two -- create a new loop for eDel. */
+ MakeFace( newFace, eDel, eDel->Lface );
+ }
+ }
+
+ /* Claim: the mesh is now in a consistent state, except that eDel->Org
+ * may have been deleted. Now we disconnect eDel->Dst.
+ */
+ if( eDelSym->Onext == eDelSym ) {
+ KillVertex( eDelSym->Org, NULL );
+ KillFace( eDelSym->Lface, NULL );
+ } else {
+ /* Make sure that eDel->Dst and eDel->Lface point to valid half-edges */
+ eDel->Lface->anEdge = eDelSym->Oprev;
+ eDelSym->Org->anEdge = eDelSym->Onext;
+ Splice( eDelSym, eDelSym->Oprev );
+ }
+
+ /* Any isolated vertices or faces have already been freed. */
+ KillEdge( eDel );
+
+ return 1;
+}
+
+
+/******************** Other Edge Operations **********************/
+
+/* All these routines can be implemented with the basic edge
+ * operations above. They are provided for convenience and efficiency.
+ */
+
+
+/* __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that
+ * eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex.
+ * eOrg and eNew will have the same left face.
+ */
+GLUhalfEdge *__gl_meshAddEdgeVertex( GLUhalfEdge *eOrg )
+{
+ GLUhalfEdge *eNewSym;
+ GLUhalfEdge *eNew = MakeEdge( eOrg );
+ if (eNew == NULL) return NULL;
+
+ eNewSym = eNew->Sym;
+
+ /* Connect the new edge appropriately */
+ Splice( eNew, eOrg->Lnext );
+
+ /* Set the vertex and face information */
+ eNew->Org = eOrg->Dst;
+ {
+ GLUvertex *newVertex= allocVertex();
+ if (newVertex == NULL) return NULL;
+
+ MakeVertex( newVertex, eNewSym, eNew->Org );
+ }
+ eNew->Lface = eNewSym->Lface = eOrg->Lface;
+
+ return eNew;
+}
+
+
+/* __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew,
+ * such that eNew == eOrg->Lnext. The new vertex is eOrg->Dst == eNew->Org.
+ * eOrg and eNew will have the same left face.
+ */
+GLUhalfEdge *__gl_meshSplitEdge( GLUhalfEdge *eOrg )
+{
+ GLUhalfEdge *eNew;
+ GLUhalfEdge *tempHalfEdge= __gl_meshAddEdgeVertex( eOrg );
+ if (tempHalfEdge == NULL) return NULL;
+
+ eNew = tempHalfEdge->Sym;
+
+ /* Disconnect eOrg from eOrg->Dst and connect it to eNew->Org */
+ Splice( eOrg->Sym, eOrg->Sym->Oprev );
+ Splice( eOrg->Sym, eNew );
+
+ /* Set the vertex and face information */
+ eOrg->Dst = eNew->Org;
+ eNew->Dst->anEdge = eNew->Sym; /* may have pointed to eOrg->Sym */
+ eNew->Rface = eOrg->Rface;
+ eNew->winding = eOrg->winding; /* copy old winding information */
+ eNew->Sym->winding = eOrg->Sym->winding;
+
+ return eNew;
+}
+
+
+/* __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst
+ * to eDst->Org, and returns the corresponding half-edge eNew.
+ * If eOrg->Lface == eDst->Lface, this splits one loop into two,
+ * and the newly created loop is eNew->Lface. Otherwise, two disjoint
+ * loops are merged into one, and the loop eDst->Lface is destroyed.
+ *
+ * If (eOrg == eDst), the new face will have only two edges.
+ * If (eOrg->Lnext == eDst), the old face is reduced to a single edge.
+ * If (eOrg->Lnext->Lnext == eDst), the old face is reduced to two edges.
+ */
+GLUhalfEdge *__gl_meshConnect( GLUhalfEdge *eOrg, GLUhalfEdge *eDst )
+{
+ GLUhalfEdge *eNewSym;
+ int joiningLoops = FALSE;
+ GLUhalfEdge *eNew = MakeEdge( eOrg );
+ if (eNew == NULL) return NULL;
+
+ eNewSym = eNew->Sym;
+
+ if( eDst->Lface != eOrg->Lface ) {
+ /* We are connecting two disjoint loops -- destroy eDst->Lface */
+ joiningLoops = TRUE;
+ KillFace( eDst->Lface, eOrg->Lface );
+ }
+
+ /* Connect the new edge appropriately */
+ Splice( eNew, eOrg->Lnext );
+ Splice( eNewSym, eDst );
+
+ /* Set the vertex and face information */
+ eNew->Org = eOrg->Dst;
+ eNewSym->Org = eDst->Org;
+ eNew->Lface = eNewSym->Lface = eOrg->Lface;
+
+ /* Make sure the old face points to a valid half-edge */
+ eOrg->Lface->anEdge = eNewSym;
+
+ if( ! joiningLoops ) {
+ GLUface *newFace= allocFace();
+ if (newFace == NULL) return NULL;
+
+ /* We split one loop into two -- the new loop is eNew->Lface */
+ MakeFace( newFace, eNew, eOrg->Lface );
+ }
+ return eNew;
+}
+
+
+/******************** Other Operations **********************/
+
+/* __gl_meshZapFace( fZap ) destroys a face and removes it from the
+ * global face list. All edges of fZap will have a NULL pointer as their
+ * left face. Any edges which also have a NULL pointer as their right face
+ * are deleted entirely (along with any isolated vertices this produces).
+ * An entire mesh can be deleted by zapping its faces, one at a time,
+ * in any order. Zapped faces cannot be used in further mesh operations!
+ */
+void __gl_meshZapFace( GLUface *fZap )
+{
+ GLUhalfEdge *eStart = fZap->anEdge;
+ GLUhalfEdge *e, *eNext, *eSym;
+ GLUface *fPrev, *fNext;
+
+ /* walk around face, deleting edges whose right face is also NULL */
+ eNext = eStart->Lnext;
+ do {
+ e = eNext;
+ eNext = e->Lnext;
+
+ e->Lface = NULL;
+ if( e->Rface == NULL ) {
+ /* delete the edge -- see __gl_MeshDelete above */
+
+ if( e->Onext == e ) {
+ KillVertex( e->Org, NULL );
+ } else {
+ /* Make sure that e->Org points to a valid half-edge */
+ e->Org->anEdge = e->Onext;
+ Splice( e, e->Oprev );
+ }
+ eSym = e->Sym;
+ if( eSym->Onext == eSym ) {
+ KillVertex( eSym->Org, NULL );
+ } else {
+ /* Make sure that eSym->Org points to a valid half-edge */
+ eSym->Org->anEdge = eSym->Onext;
+ Splice( eSym, eSym->Oprev );
+ }
+ KillEdge( e );
+ }
+ } while( e != eStart );
+
+ /* delete from circular doubly-linked list */
+ fPrev = fZap->prev;
+ fNext = fZap->next;
+ fNext->prev = fPrev;
+ fPrev->next = fNext;
+
+ memFree( fZap );
+}
+
+
+/* __gl_meshNewMesh() creates a new mesh with no edges, no vertices,
+ * and no loops (what we usually call a "face").
+ */
+GLUmesh *__gl_meshNewMesh( void )
+{
+ GLUvertex *v;
+ GLUface *f;
+ GLUhalfEdge *e;
+ GLUhalfEdge *eSym;
+ GLUmesh *mesh = (GLUmesh *)memAlloc( sizeof( GLUmesh ));
+ if (mesh == NULL) {
+ return NULL;
+ }
+
+ v = &mesh->vHead;
+ f = &mesh->fHead;
+ e = &mesh->eHead;
+ eSym = &mesh->eHeadSym;
+
+ v->next = v->prev = v;
+ v->anEdge = NULL;
+ v->data = NULL;
+
+ f->next = f->prev = f;
+ f->anEdge = NULL;
+ f->data = NULL;
+ f->trail = NULL;
+ f->marked = FALSE;
+ f->inside = FALSE;
+
+ e->next = e;
+ e->Sym = eSym;
+ e->Onext = NULL;
+ e->Lnext = NULL;
+ e->Org = NULL;
+ e->Lface = NULL;
+ e->winding = 0;
+ e->activeRegion = NULL;
+
+ eSym->next = eSym;
+ eSym->Sym = e;
+ eSym->Onext = NULL;
+ eSym->Lnext = NULL;
+ eSym->Org = NULL;
+ eSym->Lface = NULL;
+ eSym->winding = 0;
+ eSym->activeRegion = NULL;
+
+ return mesh;
+}
+
+
+/* __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in
+ * both meshes, and returns the new mesh (the old meshes are destroyed).
+ */
+GLUmesh *__gl_meshUnion( GLUmesh *mesh1, GLUmesh *mesh2 )
+{
+ GLUface *f1 = &mesh1->fHead;
+ GLUvertex *v1 = &mesh1->vHead;
+ GLUhalfEdge *e1 = &mesh1->eHead;
+ GLUface *f2 = &mesh2->fHead;
+ GLUvertex *v2 = &mesh2->vHead;
+ GLUhalfEdge *e2 = &mesh2->eHead;
+
+ /* Add the faces, vertices, and edges of mesh2 to those of mesh1 */
+ if( f2->next != f2 ) {
+ f1->prev->next = f2->next;
+ f2->next->prev = f1->prev;
+ f2->prev->next = f1;
+ f1->prev = f2->prev;
+ }
+
+ if( v2->next != v2 ) {
+ v1->prev->next = v2->next;
+ v2->next->prev = v1->prev;
+ v2->prev->next = v1;
+ v1->prev = v2->prev;
+ }
+
+ if( e2->next != e2 ) {
+ e1->Sym->next->Sym->next = e2->next;
+ e2->next->Sym->next = e1->Sym->next;
+ e2->Sym->next->Sym->next = e1;
+ e1->Sym->next = e2->Sym->next;
+ }
+
+ memFree( mesh2 );
+ return mesh1;
+}
+
+
+#ifdef DELETE_BY_ZAPPING
+
+/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ */
+void __gl_meshDeleteMesh( GLUmesh *mesh )
+{
+ GLUface *fHead = &mesh->fHead;
+
+ while( fHead->next != fHead ) {
+ __gl_meshZapFace( fHead->next );
+ }
+ assert( mesh->vHead.next == &mesh->vHead );
+
+ memFree( mesh );
+}
+
+#else
+
+/* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ */
+void __gl_meshDeleteMesh( GLUmesh *mesh )
+{
+ GLUface *f, *fNext;
+ GLUvertex *v, *vNext;
+ GLUhalfEdge *e, *eNext;
+
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) {
+ fNext = f->next;
+ memFree( f );
+ }
+
+ for( v = mesh->vHead.next; v != &mesh->vHead; v = vNext ) {
+ vNext = v->next;
+ memFree( v );
+ }
+
+ for( e = mesh->eHead.next; e != &mesh->eHead; e = eNext ) {
+ /* One call frees both e and e->Sym (see EdgePair above) */
+ eNext = e->next;
+ memFree( e );
+ }
+
+ memFree( mesh );
+}
+
+#endif
+
+#ifndef NDEBUG
+
+/* __gl_meshCheckMesh( mesh ) checks a mesh for self-consistency.
+ */
+void __gl_meshCheckMesh( GLUmesh *mesh )
+{
+ GLUface *fHead = &mesh->fHead;
+ GLUvertex *vHead = &mesh->vHead;
+ GLUhalfEdge *eHead = &mesh->eHead;
+ GLUface *f, *fPrev;
+ GLUvertex *v, *vPrev;
+ GLUhalfEdge *e, *ePrev;
+
+ fPrev = fHead;
+ for( fPrev = fHead ; (f = fPrev->next) != fHead; fPrev = f) {
+ assert( f->prev == fPrev );
+ e = f->anEdge;
+ do {
+ assert( e->Sym != e );
+ assert( e->Sym->Sym == e );
+ assert( e->Lnext->Onext->Sym == e );
+ assert( e->Onext->Sym->Lnext == e );
+ assert( e->Lface == f );
+ e = e->Lnext;
+ } while( e != f->anEdge );
+ }
+ assert( f->prev == fPrev && f->anEdge == NULL && f->data == NULL );
+
+ vPrev = vHead;
+ for( vPrev = vHead ; (v = vPrev->next) != vHead; vPrev = v) {
+ assert( v->prev == vPrev );
+ e = v->anEdge;
+ do {
+ assert( e->Sym != e );
+ assert( e->Sym->Sym == e );
+ assert( e->Lnext->Onext->Sym == e );
+ assert( e->Onext->Sym->Lnext == e );
+ assert( e->Org == v );
+ e = e->Onext;
+ } while( e != v->anEdge );
+ }
+ assert( v->prev == vPrev && v->anEdge == NULL && v->data == NULL );
+
+ ePrev = eHead;
+ for( ePrev = eHead ; (e = ePrev->next) != eHead; ePrev = e) {
+ assert( e->Sym->next == ePrev->Sym );
+ assert( e->Sym != e );
+ assert( e->Sym->Sym == e );
+ assert( e->Org != NULL );
+ assert( e->Dst != NULL );
+ assert( e->Lnext->Onext->Sym == e );
+ assert( e->Onext->Sym->Lnext == e );
+ }
+ assert( e->Sym->next == ePrev->Sym
+ && e->Sym == &mesh->eHeadSym
+ && e->Sym->Sym == e
+ && e->Org == NULL && e->Dst == NULL
+ && e->Lface == NULL && e->Rface == NULL );
+}
+
+#endif
diff --git a/cogl/tesselator/mesh.h b/cogl/tesselator/mesh.h
new file mode 100644
index 000000000..690c5f2f6
--- /dev/null
+++ b/cogl/tesselator/mesh.h
@@ -0,0 +1,266 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __mesh_h_
+#define __mesh_h_
+
+#include
+
+typedef struct GLUmesh GLUmesh;
+
+typedef struct GLUvertex GLUvertex;
+typedef struct GLUface GLUface;
+typedef struct GLUhalfEdge GLUhalfEdge;
+
+typedef struct ActiveRegion ActiveRegion; /* Internal data */
+
+/* The mesh structure is similar in spirit, notation, and operations
+ * to the "quad-edge" structure (see L. Guibas and J. Stolfi, Primitives
+ * for the manipulation of general subdivisions and the computation of
+ * Voronoi diagrams, ACM Transactions on Graphics, 4(2):74-123, April 1985).
+ * For a simplified description, see the course notes for CS348a,
+ * "Mathematical Foundations of Computer Graphics", available at the
+ * Stanford bookstore (and taught during the fall quarter).
+ * The implementation also borrows a tiny subset of the graph-based approach
+ * use in Mantyla's Geometric Work Bench (see M. Mantyla, An Introduction
+ * to Sold Modeling, Computer Science Press, Rockville, Maryland, 1988).
+ *
+ * The fundamental data structure is the "half-edge". Two half-edges
+ * go together to make an edge, but they point in opposite directions.
+ * Each half-edge has a pointer to its mate (the "symmetric" half-edge Sym),
+ * its origin vertex (Org), the face on its left side (Lface), and the
+ * adjacent half-edges in the CCW direction around the origin vertex
+ * (Onext) and around the left face (Lnext). There is also a "next"
+ * pointer for the global edge list (see below).
+ *
+ * The notation used for mesh navigation:
+ * Sym = the mate of a half-edge (same edge, but opposite direction)
+ * Onext = edge CCW around origin vertex (keep same origin)
+ * Dnext = edge CCW around destination vertex (keep same dest)
+ * Lnext = edge CCW around left face (dest becomes new origin)
+ * Rnext = edge CCW around right face (origin becomes new dest)
+ *
+ * "prev" means to substitute CW for CCW in the definitions above.
+ *
+ * The mesh keeps global lists of all vertices, faces, and edges,
+ * stored as doubly-linked circular lists with a dummy header node.
+ * The mesh stores pointers to these dummy headers (vHead, fHead, eHead).
+ *
+ * The circular edge list is special; since half-edges always occur
+ * in pairs (e and e->Sym), each half-edge stores a pointer in only
+ * one direction. Starting at eHead and following the e->next pointers
+ * will visit each *edge* once (ie. e or e->Sym, but not both).
+ * e->Sym stores a pointer in the opposite direction, thus it is
+ * always true that e->Sym->next->Sym->next == e.
+ *
+ * Each vertex has a pointer to next and previous vertices in the
+ * circular list, and a pointer to a half-edge with this vertex as
+ * the origin (NULL if this is the dummy header). There is also a
+ * field "data" for client data.
+ *
+ * Each face has a pointer to the next and previous faces in the
+ * circular list, and a pointer to a half-edge with this face as
+ * the left face (NULL if this is the dummy header). There is also
+ * a field "data" for client data.
+ *
+ * Note that what we call a "face" is really a loop; faces may consist
+ * of more than one loop (ie. not simply connected), but there is no
+ * record of this in the data structure. The mesh may consist of
+ * several disconnected regions, so it may not be possible to visit
+ * the entire mesh by starting at a half-edge and traversing the edge
+ * structure.
+ *
+ * The mesh does NOT support isolated vertices; a vertex is deleted along
+ * with its last edge. Similarly when two faces are merged, one of the
+ * faces is deleted (see __gl_meshDelete below). For mesh operations,
+ * all face (loop) and vertex pointers must not be NULL. However, once
+ * mesh manipulation is finished, __gl_MeshZapFace can be used to delete
+ * faces of the mesh, one at a time. All external faces can be "zapped"
+ * before the mesh is returned to the client; then a NULL face indicates
+ * a region which is not part of the output polygon.
+ */
+
+struct GLUvertex {
+ GLUvertex *next; /* next vertex (never NULL) */
+ GLUvertex *prev; /* previous vertex (never NULL) */
+ GLUhalfEdge *anEdge; /* a half-edge with this origin */
+ void *data; /* client's data */
+
+ /* Internal data (keep hidden) */
+ GLdouble coords[3]; /* vertex location in 3D */
+ GLdouble s, t; /* projection onto the sweep plane */
+ long pqHandle; /* to allow deletion from priority queue */
+};
+
+struct GLUface {
+ GLUface *next; /* next face (never NULL) */
+ GLUface *prev; /* previous face (never NULL) */
+ GLUhalfEdge *anEdge; /* a half edge with this left face */
+ void *data; /* room for client's data */
+
+ /* Internal data (keep hidden) */
+ GLUface *trail; /* "stack" for conversion to strips */
+ GLboolean marked; /* flag for conversion to strips */
+ GLboolean inside; /* this face is in the polygon interior */
+};
+
+struct GLUhalfEdge {
+ GLUhalfEdge *next; /* doubly-linked list (prev==Sym->next) */
+ GLUhalfEdge *Sym; /* same edge, opposite direction */
+ GLUhalfEdge *Onext; /* next edge CCW around origin */
+ GLUhalfEdge *Lnext; /* next edge CCW around left face */
+ GLUvertex *Org; /* origin vertex (Overtex too long) */
+ GLUface *Lface; /* left face */
+
+ /* Internal data (keep hidden) */
+ ActiveRegion *activeRegion; /* a region with this upper edge (sweep.c) */
+ int winding; /* change in winding number when crossing
+ from the right face to the left face */
+};
+
+#define Rface Sym->Lface
+#define Dst Sym->Org
+
+#define Oprev Sym->Lnext
+#define Lprev Onext->Sym
+#define Dprev Lnext->Sym
+#define Rprev Sym->Onext
+#define Dnext Rprev->Sym /* 3 pointers */
+#define Rnext Oprev->Sym /* 3 pointers */
+
+
+struct GLUmesh {
+ GLUvertex vHead; /* dummy header for vertex list */
+ GLUface fHead; /* dummy header for face list */
+ GLUhalfEdge eHead; /* dummy header for edge list */
+ GLUhalfEdge eHeadSym; /* and its symmetric counterpart */
+};
+
+/* The mesh operations below have three motivations: completeness,
+ * convenience, and efficiency. The basic mesh operations are MakeEdge,
+ * Splice, and Delete. All the other edge operations can be implemented
+ * in terms of these. The other operations are provided for convenience
+ * and/or efficiency.
+ *
+ * When a face is split or a vertex is added, they are inserted into the
+ * global list *before* the existing vertex or face (ie. e->Org or e->Lface).
+ * This makes it easier to process all vertices or faces in the global lists
+ * without worrying about processing the same data twice. As a convenience,
+ * when a face is split, the "inside" flag is copied from the old face.
+ * Other internal data (v->data, v->activeRegion, f->data, f->marked,
+ * f->trail, e->winding) is set to zero.
+ *
+ * ********************** Basic Edge Operations **************************
+ *
+ * __gl_meshMakeEdge( mesh ) creates one edge, two vertices, and a loop.
+ * The loop (face) consists of the two new half-edges.
+ *
+ * __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the
+ * mesh connectivity and topology. It changes the mesh so that
+ * eOrg->Onext <- OLD( eDst->Onext )
+ * eDst->Onext <- OLD( eOrg->Onext )
+ * where OLD(...) means the value before the meshSplice operation.
+ *
+ * This can have two effects on the vertex structure:
+ * - if eOrg->Org != eDst->Org, the two vertices are merged together
+ * - if eOrg->Org == eDst->Org, the origin is split into two vertices
+ * In both cases, eDst->Org is changed and eOrg->Org is untouched.
+ *
+ * Similarly (and independently) for the face structure,
+ * - if eOrg->Lface == eDst->Lface, one loop is split into two
+ * - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one
+ * In both cases, eDst->Lface is changed and eOrg->Lface is unaffected.
+ *
+ * __gl_meshDelete( eDel ) removes the edge eDel. There are several cases:
+ * if (eDel->Lface != eDel->Rface), we join two loops into one; the loop
+ * eDel->Lface is deleted. Otherwise, we are splitting one loop into two;
+ * the newly created loop will contain eDel->Dst. If the deletion of eDel
+ * would create isolated vertices, those are deleted as well.
+ *
+ * ********************** Other Edge Operations **************************
+ *
+ * __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that
+ * eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex.
+ * eOrg and eNew will have the same left face.
+ *
+ * __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew,
+ * such that eNew == eOrg->Lnext. The new vertex is eOrg->Dst == eNew->Org.
+ * eOrg and eNew will have the same left face.
+ *
+ * __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst
+ * to eDst->Org, and returns the corresponding half-edge eNew.
+ * If eOrg->Lface == eDst->Lface, this splits one loop into two,
+ * and the newly created loop is eNew->Lface. Otherwise, two disjoint
+ * loops are merged into one, and the loop eDst->Lface is destroyed.
+ *
+ * ************************ Other Operations *****************************
+ *
+ * __gl_meshNewMesh() creates a new mesh with no edges, no vertices,
+ * and no loops (what we usually call a "face").
+ *
+ * __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in
+ * both meshes, and returns the new mesh (the old meshes are destroyed).
+ *
+ * __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
+ *
+ * __gl_meshZapFace( fZap ) destroys a face and removes it from the
+ * global face list. All edges of fZap will have a NULL pointer as their
+ * left face. Any edges which also have a NULL pointer as their right face
+ * are deleted entirely (along with any isolated vertices this produces).
+ * An entire mesh can be deleted by zapping its faces, one at a time,
+ * in any order. Zapped faces cannot be used in further mesh operations!
+ *
+ * __gl_meshCheckMesh( mesh ) checks a mesh for self-consistency.
+ */
+
+GLUhalfEdge *__gl_meshMakeEdge( GLUmesh *mesh );
+int __gl_meshSplice( GLUhalfEdge *eOrg, GLUhalfEdge *eDst );
+int __gl_meshDelete( GLUhalfEdge *eDel );
+
+GLUhalfEdge *__gl_meshAddEdgeVertex( GLUhalfEdge *eOrg );
+GLUhalfEdge *__gl_meshSplitEdge( GLUhalfEdge *eOrg );
+GLUhalfEdge *__gl_meshConnect( GLUhalfEdge *eOrg, GLUhalfEdge *eDst );
+
+GLUmesh *__gl_meshNewMesh( void );
+GLUmesh *__gl_meshUnion( GLUmesh *mesh1, GLUmesh *mesh2 );
+void __gl_meshDeleteMesh( GLUmesh *mesh );
+void __gl_meshZapFace( GLUface *fZap );
+
+#ifdef NDEBUG
+#define __gl_meshCheckMesh( mesh )
+#else
+void __gl_meshCheckMesh( GLUmesh *mesh );
+#endif
+
+#endif
diff --git a/cogl/tesselator/normal.c b/cogl/tesselator/normal.c
new file mode 100644
index 000000000..7ab83167b
--- /dev/null
+++ b/cogl/tesselator/normal.c
@@ -0,0 +1,253 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include "mesh.h"
+#include "tess.h"
+#include "normal.h"
+#include
+#include
+
+#define TRUE 1
+#define FALSE 0
+
+#define Dot(u,v) (u[0]*v[0] + u[1]*v[1] + u[2]*v[2])
+
+#if 0
+static void Normalize( GLdouble v[3] )
+{
+ GLdouble len = v[0]*v[0] + v[1]*v[1] + v[2]*v[2];
+
+ assert( len > 0 );
+ len = sqrt( len );
+ v[0] /= len;
+ v[1] /= len;
+ v[2] /= len;
+}
+#endif
+
+#undef ABS
+#define ABS(x) ((x) < 0 ? -(x) : (x))
+
+static int LongAxis( GLdouble v[3] )
+{
+ int i = 0;
+
+ if( ABS(v[1]) > ABS(v[0]) ) { i = 1; }
+ if( ABS(v[2]) > ABS(v[i]) ) { i = 2; }
+ return i;
+}
+
+static void ComputeNormal( GLUtesselator *tess, GLdouble norm[3] )
+{
+ GLUvertex *v, *v1, *v2;
+ GLdouble c, tLen2, maxLen2;
+ GLdouble maxVal[3], minVal[3], d1[3], d2[3], tNorm[3];
+ GLUvertex *maxVert[3], *minVert[3];
+ GLUvertex *vHead = &tess->mesh->vHead;
+ int i;
+
+ maxVal[0] = maxVal[1] = maxVal[2] = -2 * GLU_TESS_MAX_COORD;
+ minVal[0] = minVal[1] = minVal[2] = 2 * GLU_TESS_MAX_COORD;
+
+ for( v = vHead->next; v != vHead; v = v->next ) {
+ for( i = 0; i < 3; ++i ) {
+ c = v->coords[i];
+ if( c < minVal[i] ) { minVal[i] = c; minVert[i] = v; }
+ if( c > maxVal[i] ) { maxVal[i] = c; maxVert[i] = v; }
+ }
+ }
+
+ /* Find two vertices separated by at least 1/sqrt(3) of the maximum
+ * distance between any two vertices
+ */
+ i = 0;
+ if( maxVal[1] - minVal[1] > maxVal[0] - minVal[0] ) { i = 1; }
+ if( maxVal[2] - minVal[2] > maxVal[i] - minVal[i] ) { i = 2; }
+ if( minVal[i] >= maxVal[i] ) {
+ /* All vertices are the same -- normal doesn't matter */
+ norm[0] = 0; norm[1] = 0; norm[2] = 1;
+ return;
+ }
+
+ /* Look for a third vertex which forms the triangle with maximum area
+ * (Length of normal == twice the triangle area)
+ */
+ maxLen2 = 0;
+ v1 = minVert[i];
+ v2 = maxVert[i];
+ d1[0] = v1->coords[0] - v2->coords[0];
+ d1[1] = v1->coords[1] - v2->coords[1];
+ d1[2] = v1->coords[2] - v2->coords[2];
+ for( v = vHead->next; v != vHead; v = v->next ) {
+ d2[0] = v->coords[0] - v2->coords[0];
+ d2[1] = v->coords[1] - v2->coords[1];
+ d2[2] = v->coords[2] - v2->coords[2];
+ tNorm[0] = d1[1]*d2[2] - d1[2]*d2[1];
+ tNorm[1] = d1[2]*d2[0] - d1[0]*d2[2];
+ tNorm[2] = d1[0]*d2[1] - d1[1]*d2[0];
+ tLen2 = tNorm[0]*tNorm[0] + tNorm[1]*tNorm[1] + tNorm[2]*tNorm[2];
+ if( tLen2 > maxLen2 ) {
+ maxLen2 = tLen2;
+ norm[0] = tNorm[0];
+ norm[1] = tNorm[1];
+ norm[2] = tNorm[2];
+ }
+ }
+
+ if( maxLen2 <= 0 ) {
+ /* All points lie on a single line -- any decent normal will do */
+ norm[0] = norm[1] = norm[2] = 0;
+ norm[LongAxis(d1)] = 1;
+ }
+}
+
+
+static void CheckOrientation( GLUtesselator *tess )
+{
+ GLdouble area;
+ GLUface *f, *fHead = &tess->mesh->fHead;
+ GLUvertex *v, *vHead = &tess->mesh->vHead;
+ GLUhalfEdge *e;
+
+ /* When we compute the normal automatically, we choose the orientation
+ * so that the sum of the signed areas of all contours is non-negative.
+ */
+ area = 0;
+ for( f = fHead->next; f != fHead; f = f->next ) {
+ e = f->anEdge;
+ if( e->winding <= 0 ) continue;
+ do {
+ area += (e->Org->s - e->Dst->s) * (e->Org->t + e->Dst->t);
+ e = e->Lnext;
+ } while( e != f->anEdge );
+ }
+ if( area < 0 ) {
+ /* Reverse the orientation by flipping all the t-coordinates */
+ for( v = vHead->next; v != vHead; v = v->next ) {
+ v->t = - v->t;
+ }
+ tess->tUnit[0] = - tess->tUnit[0];
+ tess->tUnit[1] = - tess->tUnit[1];
+ tess->tUnit[2] = - tess->tUnit[2];
+ }
+}
+
+#ifdef FOR_TRITE_TEST_PROGRAM
+#include
+extern int RandomSweep;
+#define S_UNIT_X (RandomSweep ? (2*drand48()-1) : 1.0)
+#define S_UNIT_Y (RandomSweep ? (2*drand48()-1) : 0.0)
+#else
+#if defined(SLANTED_SWEEP)
+/* The "feature merging" is not intended to be complete. There are
+ * special cases where edges are nearly parallel to the sweep line
+ * which are not implemented. The algorithm should still behave
+ * robustly (ie. produce a reasonable tesselation) in the presence
+ * of such edges, however it may miss features which could have been
+ * merged. We could minimize this effect by choosing the sweep line
+ * direction to be something unusual (ie. not parallel to one of the
+ * coordinate axes).
+ */
+#define S_UNIT_X 0.50941539564955385 /* Pre-normalized */
+#define S_UNIT_Y 0.86052074622010633
+#else
+#define S_UNIT_X 1.0
+#define S_UNIT_Y 0.0
+#endif
+#endif
+
+/* Determine the polygon normal and project vertices onto the plane
+ * of the polygon.
+ */
+void __gl_projectPolygon( GLUtesselator *tess )
+{
+ GLUvertex *v, *vHead = &tess->mesh->vHead;
+ GLdouble norm[3];
+ GLdouble *sUnit, *tUnit;
+ int i, computedNormal = FALSE;
+
+ norm[0] = tess->normal[0];
+ norm[1] = tess->normal[1];
+ norm[2] = tess->normal[2];
+ if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) {
+ ComputeNormal( tess, norm );
+ computedNormal = TRUE;
+ }
+ sUnit = tess->sUnit;
+ tUnit = tess->tUnit;
+ i = LongAxis( norm );
+
+#if defined(FOR_TRITE_TEST_PROGRAM) || defined(TRUE_PROJECT)
+ /* Choose the initial sUnit vector to be approximately perpendicular
+ * to the normal.
+ */
+ Normalize( norm );
+
+ sUnit[i] = 0;
+ sUnit[(i+1)%3] = S_UNIT_X;
+ sUnit[(i+2)%3] = S_UNIT_Y;
+
+ /* Now make it exactly perpendicular */
+ w = Dot( sUnit, norm );
+ sUnit[0] -= w * norm[0];
+ sUnit[1] -= w * norm[1];
+ sUnit[2] -= w * norm[2];
+ Normalize( sUnit );
+
+ /* Choose tUnit so that (sUnit,tUnit,norm) form a right-handed frame */
+ tUnit[0] = norm[1]*sUnit[2] - norm[2]*sUnit[1];
+ tUnit[1] = norm[2]*sUnit[0] - norm[0]*sUnit[2];
+ tUnit[2] = norm[0]*sUnit[1] - norm[1]*sUnit[0];
+ Normalize( tUnit );
+#else
+ /* Project perpendicular to a coordinate axis -- better numerically */
+ sUnit[i] = 0;
+ sUnit[(i+1)%3] = S_UNIT_X;
+ sUnit[(i+2)%3] = S_UNIT_Y;
+
+ tUnit[i] = 0;
+ tUnit[(i+1)%3] = (norm[i] > 0) ? -S_UNIT_Y : S_UNIT_Y;
+ tUnit[(i+2)%3] = (norm[i] > 0) ? S_UNIT_X : -S_UNIT_X;
+#endif
+
+ /* Project the vertices onto the sweep plane */
+ for( v = vHead->next; v != vHead; v = v->next ) {
+ v->s = Dot( v->coords, sUnit );
+ v->t = Dot( v->coords, tUnit );
+ }
+ if( computedNormal ) {
+ CheckOrientation( tess );
+ }
+}
diff --git a/cogl/tesselator/normal.h b/cogl/tesselator/normal.h
new file mode 100644
index 000000000..c376ca445
--- /dev/null
+++ b/cogl/tesselator/normal.h
@@ -0,0 +1,45 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __normal_h_
+#define __normal_h_
+
+#include "tess.h"
+
+/* __gl_projectPolygon( tess ) determines the polygon normal
+ * and project vertices onto the plane of the polygon.
+ */
+void __gl_projectPolygon( GLUtesselator *tess );
+
+#endif
diff --git a/cogl/tesselator/priorityq-heap.c b/cogl/tesselator/priorityq-heap.c
new file mode 100644
index 000000000..e3a6c6068
--- /dev/null
+++ b/cogl/tesselator/priorityq-heap.c
@@ -0,0 +1,252 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include
+#include
+#include "priorityq-heap.h"
+#include "memalloc.h"
+
+#define INIT_SIZE 32
+
+#define TRUE 1
+#define FALSE 0
+
+#ifdef FOR_TRITE_TEST_PROGRAM
+#define LEQ(x,y) (*pq->leq)(x,y)
+#else
+/* Violates modularity, but a little faster */
+#include "geom.h"
+#define LEQ(x,y) VertLeq((GLUvertex *)x, (GLUvertex *)y)
+#endif
+
+/* really __gl_pqHeapNewPriorityQ */
+PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
+{
+ PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
+ if (pq == NULL) return NULL;
+
+ pq->size = 0;
+ pq->max = INIT_SIZE;
+ pq->nodes = (PQnode *)memAlloc( (INIT_SIZE + 1) * sizeof(pq->nodes[0]) );
+ if (pq->nodes == NULL) {
+ memFree(pq);
+ return NULL;
+ }
+
+ pq->handles = (PQhandleElem *)memAlloc( (INIT_SIZE + 1) * sizeof(pq->handles[0]) );
+ if (pq->handles == NULL) {
+ memFree(pq->nodes);
+ memFree(pq);
+ return NULL;
+ }
+
+ pq->initialized = FALSE;
+ pq->freeList = 0;
+ pq->leq = leq;
+
+ pq->nodes[1].handle = 1; /* so that Minimum() returns NULL */
+ pq->handles[1].key = NULL;
+ return pq;
+}
+
+/* really __gl_pqHeapDeletePriorityQ */
+void pqDeletePriorityQ( PriorityQ *pq )
+{
+ memFree( pq->handles );
+ memFree( pq->nodes );
+ memFree( pq );
+}
+
+
+static void FloatDown( PriorityQ *pq, long curr )
+{
+ PQnode *n = pq->nodes;
+ PQhandleElem *h = pq->handles;
+ PQhandle hCurr, hChild;
+ long child;
+
+ hCurr = n[curr].handle;
+ for( ;; ) {
+ child = curr << 1;
+ if( child < pq->size && LEQ( h[n[child+1].handle].key,
+ h[n[child].handle].key )) {
+ ++child;
+ }
+
+ assert(child <= pq->max);
+
+ hChild = n[child].handle;
+ if( child > pq->size || LEQ( h[hCurr].key, h[hChild].key )) {
+ n[curr].handle = hCurr;
+ h[hCurr].node = curr;
+ break;
+ }
+ n[curr].handle = hChild;
+ h[hChild].node = curr;
+ curr = child;
+ }
+}
+
+
+static void FloatUp( PriorityQ *pq, long curr )
+{
+ PQnode *n = pq->nodes;
+ PQhandleElem *h = pq->handles;
+ PQhandle hCurr, hParent;
+ long parent;
+
+ hCurr = n[curr].handle;
+ for( ;; ) {
+ parent = curr >> 1;
+ hParent = n[parent].handle;
+ if( parent == 0 || LEQ( h[hParent].key, h[hCurr].key )) {
+ n[curr].handle = hCurr;
+ h[hCurr].node = curr;
+ break;
+ }
+ n[curr].handle = hParent;
+ h[hParent].node = curr;
+ curr = parent;
+ }
+}
+
+/* really __gl_pqHeapInit */
+void pqInit( PriorityQ *pq )
+{
+ long i;
+
+ /* This method of building a heap is O(n), rather than O(n lg n). */
+
+ for( i = pq->size; i >= 1; --i ) {
+ FloatDown( pq, i );
+ }
+ pq->initialized = TRUE;
+}
+
+/* really __gl_pqHeapInsert */
+/* returns LONG_MAX iff out of memory */
+PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
+{
+ long curr;
+ PQhandle free;
+
+ curr = ++ pq->size;
+ if( (curr*2) > pq->max ) {
+ PQnode *saveNodes= pq->nodes;
+ PQhandleElem *saveHandles= pq->handles;
+
+ /* If the heap overflows, double its size. */
+ pq->max <<= 1;
+ pq->nodes = (PQnode *)memRealloc( pq->nodes,
+ (size_t)
+ ((pq->max + 1) * sizeof( pq->nodes[0] )));
+ if (pq->nodes == NULL) {
+ pq->nodes = saveNodes; /* restore ptr to free upon return */
+ return LONG_MAX;
+ }
+ pq->handles = (PQhandleElem *)memRealloc( pq->handles,
+ (size_t)
+ ((pq->max + 1) *
+ sizeof( pq->handles[0] )));
+ if (pq->handles == NULL) {
+ pq->handles = saveHandles; /* restore ptr to free upon return */
+ return LONG_MAX;
+ }
+ }
+
+ if( pq->freeList == 0 ) {
+ free = curr;
+ } else {
+ free = pq->freeList;
+ pq->freeList = pq->handles[free].node;
+ }
+
+ pq->nodes[curr].handle = free;
+ pq->handles[free].node = curr;
+ pq->handles[free].key = keyNew;
+
+ if( pq->initialized ) {
+ FloatUp( pq, curr );
+ }
+ assert(free != LONG_MAX);
+ return free;
+}
+
+/* really __gl_pqHeapExtractMin */
+PQkey pqExtractMin( PriorityQ *pq )
+{
+ PQnode *n = pq->nodes;
+ PQhandleElem *h = pq->handles;
+ PQhandle hMin = n[1].handle;
+ PQkey min = h[hMin].key;
+
+ if( pq->size > 0 ) {
+ n[1].handle = n[pq->size].handle;
+ h[n[1].handle].node = 1;
+
+ h[hMin].key = NULL;
+ h[hMin].node = pq->freeList;
+ pq->freeList = hMin;
+
+ if( -- pq->size > 0 ) {
+ FloatDown( pq, 1 );
+ }
+ }
+ return min;
+}
+
+/* really __gl_pqHeapDelete */
+void pqDelete( PriorityQ *pq, PQhandle hCurr )
+{
+ PQnode *n = pq->nodes;
+ PQhandleElem *h = pq->handles;
+ long curr;
+
+ assert( hCurr >= 1 && hCurr <= pq->max && h[hCurr].key != NULL );
+
+ curr = h[hCurr].node;
+ n[curr].handle = n[pq->size].handle;
+ h[n[curr].handle].node = curr;
+
+ if( curr <= -- pq->size ) {
+ if( curr <= 1 || LEQ( h[n[curr>>1].handle].key, h[n[curr].handle].key )) {
+ FloatDown( pq, curr );
+ } else {
+ FloatUp( pq, curr );
+ }
+ }
+ h[hCurr].key = NULL;
+ h[hCurr].node = pq->freeList;
+ pq->freeList = hCurr;
+}
diff --git a/cogl/tesselator/priorityq-heap.h b/cogl/tesselator/priorityq-heap.h
new file mode 100644
index 000000000..dc9aaef87
--- /dev/null
+++ b/cogl/tesselator/priorityq-heap.h
@@ -0,0 +1,107 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __priorityq_heap_h_
+#define __priorityq_heap_h_
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey PQHeapKey
+#define PQhandle PQHeapHandle
+#define PriorityQ PriorityQHeap
+
+#define pqNewPriorityQ(leq) __gl_pqHeapNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq) __gl_pqHeapDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit. In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq) __gl_pqHeapInit(pq)
+#define pqInsert(pq,key) __gl_pqHeapInsert(pq,key)
+#define pqMinimum(pq) __gl_pqHeapMinimum(pq)
+#define pqExtractMin(pq) __gl_pqHeapExtractMin(pq)
+#define pqDelete(pq,handle) __gl_pqHeapDelete(pq,handle)
+#define pqIsEmpty(pq) __gl_pqHeapIsEmpty(pq)
+
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap. "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size. When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles". Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef void *PQkey;
+typedef long PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+typedef struct { PQhandle handle; } PQnode;
+typedef struct { PQkey key; PQhandle node; } PQhandleElem;
+
+struct PriorityQ {
+ PQnode *nodes;
+ PQhandleElem *handles;
+ long size, max;
+ PQhandle freeList;
+ int initialized;
+ int (*leq)(PQkey key1, PQkey key2);
+};
+
+PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
+void pqDeletePriorityQ( PriorityQ *pq );
+
+void pqInit( PriorityQ *pq );
+PQhandle pqInsert( PriorityQ *pq, PQkey key );
+PQkey pqExtractMin( PriorityQ *pq );
+void pqDelete( PriorityQ *pq, PQhandle handle );
+
+
+#define __gl_pqHeapMinimum(pq) ((pq)->handles[(pq)->nodes[1].handle].key)
+#define __gl_pqHeapIsEmpty(pq) ((pq)->size == 0)
+
+#endif
diff --git a/cogl/tesselator/priorityq-sort.h b/cogl/tesselator/priorityq-sort.h
new file mode 100644
index 000000000..746cf5fa6
--- /dev/null
+++ b/cogl/tesselator/priorityq-sort.h
@@ -0,0 +1,117 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __priorityq_sort_h_
+#define __priorityq_sort_h_
+
+#include "priorityq-heap.h"
+
+#undef PQkey
+#undef PQhandle
+#undef PriorityQ
+#undef pqNewPriorityQ
+#undef pqDeletePriorityQ
+#undef pqInit
+#undef pqInsert
+#undef pqMinimum
+#undef pqExtractMin
+#undef pqDelete
+#undef pqIsEmpty
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey PQSortKey
+#define PQhandle PQSortHandle
+#define PriorityQ PriorityQSort
+
+#define pqNewPriorityQ(leq) __gl_pqSortNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq) __gl_pqSortDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit. In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq) __gl_pqSortInit(pq)
+#define pqInsert(pq,key) __gl_pqSortInsert(pq,key)
+#define pqMinimum(pq) __gl_pqSortMinimum(pq)
+#define pqExtractMin(pq) __gl_pqSortExtractMin(pq)
+#define pqDelete(pq,handle) __gl_pqSortDelete(pq,handle)
+#define pqIsEmpty(pq) __gl_pqSortIsEmpty(pq)
+
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap. "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size. When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles". Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef PQHeapKey PQkey;
+typedef PQHeapHandle PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+struct PriorityQ {
+ PriorityQHeap *heap;
+ PQkey *keys;
+ PQkey **order;
+ PQhandle size, max;
+ int initialized;
+ int (*leq)(PQkey key1, PQkey key2);
+};
+
+PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
+void pqDeletePriorityQ( PriorityQ *pq );
+
+int pqInit( PriorityQ *pq );
+PQhandle pqInsert( PriorityQ *pq, PQkey key );
+PQkey pqExtractMin( PriorityQ *pq );
+void pqDelete( PriorityQ *pq, PQhandle handle );
+
+PQkey pqMinimum( PriorityQ *pq );
+int pqIsEmpty( PriorityQ *pq );
+
+#endif
diff --git a/cogl/tesselator/priorityq.c b/cogl/tesselator/priorityq.c
new file mode 100644
index 000000000..11f0263ac
--- /dev/null
+++ b/cogl/tesselator/priorityq.c
@@ -0,0 +1,260 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include
+#include /* LONG_MAX */
+#include "memalloc.h"
+
+/* Include all the code for the regular heap-based queue here. */
+
+#include "priorityq-heap.c"
+
+/* Now redefine all the function names to map to their "Sort" versions. */
+
+#include "priorityq-sort.h"
+
+/* really __gl_pqSortNewPriorityQ */
+PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) )
+{
+ PriorityQ *pq = (PriorityQ *)memAlloc( sizeof( PriorityQ ));
+ if (pq == NULL) return NULL;
+
+ pq->heap = __gl_pqHeapNewPriorityQ( leq );
+ if (pq->heap == NULL) {
+ memFree(pq);
+ return NULL;
+ }
+
+ pq->keys = (PQHeapKey *)memAlloc( INIT_SIZE * sizeof(pq->keys[0]) );
+ if (pq->keys == NULL) {
+ __gl_pqHeapDeletePriorityQ(pq->heap);
+ memFree(pq);
+ return NULL;
+ }
+
+ pq->size = 0;
+ pq->max = INIT_SIZE;
+ pq->initialized = FALSE;
+ pq->leq = leq;
+ return pq;
+}
+
+/* really __gl_pqSortDeletePriorityQ */
+void pqDeletePriorityQ( PriorityQ *pq )
+{
+ assert(pq != NULL);
+ if (pq->heap != NULL) __gl_pqHeapDeletePriorityQ( pq->heap );
+ if (pq->order != NULL) memFree( pq->order );
+ if (pq->keys != NULL) memFree( pq->keys );
+ memFree( pq );
+}
+
+
+#define LT(x,y) (! LEQ(y,x))
+#define GT(x,y) (! LEQ(x,y))
+#define Swap(a,b) if(1){PQkey *tmp = *a; *a = *b; *b = tmp;}else
+
+/* really __gl_pqSortInit */
+int pqInit( PriorityQ *pq )
+{
+ PQkey **p, **r, **i, **j, *piv;
+ struct { PQkey **p, **r; } Stack[50], *top = Stack;
+ unsigned long seed = 2016473283;
+
+ /* Create an array of indirect pointers to the keys, so that we
+ * the handles we have returned are still valid.
+ */
+/*
+ pq->order = (PQHeapKey **)memAlloc( (size_t)
+ (pq->size * sizeof(pq->order[0])) );
+*/
+ pq->order = (PQHeapKey **)memAlloc( (size_t)
+ ((pq->size+1) * sizeof(pq->order[0])) );
+/* the previous line is a patch to compensate for the fact that IBM */
+/* machines return a null on a malloc of zero bytes (unlike SGI), */
+/* so we have to put in this defense to guard against a memory */
+/* fault four lines down. from fossum@austin.ibm.com. */
+ if (pq->order == NULL) return 0;
+
+ p = pq->order;
+ r = p + pq->size - 1;
+ for( piv = pq->keys, i = p; i <= r; ++piv, ++i ) {
+ *i = piv;
+ }
+
+ /* Sort the indirect pointers in descending order,
+ * using randomized Quicksort
+ */
+ top->p = p; top->r = r; ++top;
+ while( --top >= Stack ) {
+ p = top->p;
+ r = top->r;
+ while( r > p + 10 ) {
+ seed = seed * 1539415821 + 1;
+ i = p + seed % (r - p + 1);
+ piv = *i;
+ *i = *p;
+ *p = piv;
+ i = p - 1;
+ j = r + 1;
+ do {
+ do { ++i; } while( GT( **i, *piv ));
+ do { --j; } while( LT( **j, *piv ));
+ Swap( i, j );
+ } while( i < j );
+ Swap( i, j ); /* Undo last swap */
+ if( i - p < r - j ) {
+ top->p = j+1; top->r = r; ++top;
+ r = i-1;
+ } else {
+ top->p = p; top->r = i-1; ++top;
+ p = j+1;
+ }
+ }
+ /* Insertion sort small lists */
+ for( i = p+1; i <= r; ++i ) {
+ piv = *i;
+ for( j = i; j > p && LT( **(j-1), *piv ); --j ) {
+ *j = *(j-1);
+ }
+ *j = piv;
+ }
+ }
+ pq->max = pq->size;
+ pq->initialized = TRUE;
+ __gl_pqHeapInit( pq->heap ); /* always succeeds */
+
+#ifndef NDEBUG
+ p = pq->order;
+ r = p + pq->size - 1;
+ for( i = p; i < r; ++i ) {
+ assert( LEQ( **(i+1), **i ));
+ }
+#endif
+
+ return 1;
+}
+
+/* really __gl_pqSortInsert */
+/* returns LONG_MAX iff out of memory */
+PQhandle pqInsert( PriorityQ *pq, PQkey keyNew )
+{
+ long curr;
+
+ if( pq->initialized ) {
+ return __gl_pqHeapInsert( pq->heap, keyNew );
+ }
+ curr = pq->size;
+ if( ++ pq->size >= pq->max ) {
+ PQkey *saveKey= pq->keys;
+
+ /* If the heap overflows, double its size. */
+ pq->max <<= 1;
+ pq->keys = (PQHeapKey *)memRealloc( pq->keys,
+ (size_t)
+ (pq->max * sizeof( pq->keys[0] )));
+ if (pq->keys == NULL) {
+ pq->keys = saveKey; /* restore ptr to free upon return */
+ return LONG_MAX;
+ }
+ }
+ assert(curr != LONG_MAX);
+ pq->keys[curr] = keyNew;
+
+ /* Negative handles index the sorted array. */
+ return -(curr+1);
+}
+
+/* really __gl_pqSortExtractMin */
+PQkey pqExtractMin( PriorityQ *pq )
+{
+ PQkey sortMin, heapMin;
+
+ if( pq->size == 0 ) {
+ return __gl_pqHeapExtractMin( pq->heap );
+ }
+ sortMin = *(pq->order[pq->size-1]);
+ if( ! __gl_pqHeapIsEmpty( pq->heap )) {
+ heapMin = __gl_pqHeapMinimum( pq->heap );
+ if( LEQ( heapMin, sortMin )) {
+ return __gl_pqHeapExtractMin( pq->heap );
+ }
+ }
+ do {
+ -- pq->size;
+ } while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL );
+ return sortMin;
+}
+
+/* really __gl_pqSortMinimum */
+PQkey pqMinimum( PriorityQ *pq )
+{
+ PQkey sortMin, heapMin;
+
+ if( pq->size == 0 ) {
+ return __gl_pqHeapMinimum( pq->heap );
+ }
+ sortMin = *(pq->order[pq->size-1]);
+ if( ! __gl_pqHeapIsEmpty( pq->heap )) {
+ heapMin = __gl_pqHeapMinimum( pq->heap );
+ if( LEQ( heapMin, sortMin )) {
+ return heapMin;
+ }
+ }
+ return sortMin;
+}
+
+/* really __gl_pqSortIsEmpty */
+int pqIsEmpty( PriorityQ *pq )
+{
+ return (pq->size == 0) && __gl_pqHeapIsEmpty( pq->heap );
+}
+
+/* really __gl_pqSortDelete */
+void pqDelete( PriorityQ *pq, PQhandle curr )
+{
+ if( curr >= 0 ) {
+ __gl_pqHeapDelete( pq->heap, curr );
+ return;
+ }
+ curr = -(curr+1);
+ assert( curr < pq->max && pq->keys[curr] != NULL );
+
+ pq->keys[curr] = NULL;
+ while( pq->size > 0 && *(pq->order[pq->size-1]) == NULL ) {
+ -- pq->size;
+ }
+}
diff --git a/cogl/tesselator/priorityq.h b/cogl/tesselator/priorityq.h
new file mode 100644
index 000000000..746cf5fa6
--- /dev/null
+++ b/cogl/tesselator/priorityq.h
@@ -0,0 +1,117 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __priorityq_sort_h_
+#define __priorityq_sort_h_
+
+#include "priorityq-heap.h"
+
+#undef PQkey
+#undef PQhandle
+#undef PriorityQ
+#undef pqNewPriorityQ
+#undef pqDeletePriorityQ
+#undef pqInit
+#undef pqInsert
+#undef pqMinimum
+#undef pqExtractMin
+#undef pqDelete
+#undef pqIsEmpty
+
+/* Use #define's so that another heap implementation can use this one */
+
+#define PQkey PQSortKey
+#define PQhandle PQSortHandle
+#define PriorityQ PriorityQSort
+
+#define pqNewPriorityQ(leq) __gl_pqSortNewPriorityQ(leq)
+#define pqDeletePriorityQ(pq) __gl_pqSortDeletePriorityQ(pq)
+
+/* The basic operations are insertion of a new key (pqInsert),
+ * and examination/extraction of a key whose value is minimum
+ * (pqMinimum/pqExtractMin). Deletion is also allowed (pqDelete);
+ * for this purpose pqInsert returns a "handle" which is supplied
+ * as the argument.
+ *
+ * An initial heap may be created efficiently by calling pqInsert
+ * repeatedly, then calling pqInit. In any case pqInit must be called
+ * before any operations other than pqInsert are used.
+ *
+ * If the heap is empty, pqMinimum/pqExtractMin will return a NULL key.
+ * This may also be tested with pqIsEmpty.
+ */
+#define pqInit(pq) __gl_pqSortInit(pq)
+#define pqInsert(pq,key) __gl_pqSortInsert(pq,key)
+#define pqMinimum(pq) __gl_pqSortMinimum(pq)
+#define pqExtractMin(pq) __gl_pqSortExtractMin(pq)
+#define pqDelete(pq,handle) __gl_pqSortDelete(pq,handle)
+#define pqIsEmpty(pq) __gl_pqSortIsEmpty(pq)
+
+
+/* Since we support deletion the data structure is a little more
+ * complicated than an ordinary heap. "nodes" is the heap itself;
+ * active nodes are stored in the range 1..pq->size. When the
+ * heap exceeds its allocated size (pq->max), its size doubles.
+ * The children of node i are nodes 2i and 2i+1.
+ *
+ * Each node stores an index into an array "handles". Each handle
+ * stores a key, plus a pointer back to the node which currently
+ * represents that key (ie. nodes[handles[i].node].handle == i).
+ */
+
+typedef PQHeapKey PQkey;
+typedef PQHeapHandle PQhandle;
+typedef struct PriorityQ PriorityQ;
+
+struct PriorityQ {
+ PriorityQHeap *heap;
+ PQkey *keys;
+ PQkey **order;
+ PQhandle size, max;
+ int initialized;
+ int (*leq)(PQkey key1, PQkey key2);
+};
+
+PriorityQ *pqNewPriorityQ( int (*leq)(PQkey key1, PQkey key2) );
+void pqDeletePriorityQ( PriorityQ *pq );
+
+int pqInit( PriorityQ *pq );
+PQhandle pqInsert( PriorityQ *pq, PQkey key );
+PQkey pqExtractMin( PriorityQ *pq );
+void pqDelete( PriorityQ *pq, PQhandle handle );
+
+PQkey pqMinimum( PriorityQ *pq );
+int pqIsEmpty( PriorityQ *pq );
+
+#endif
diff --git a/cogl/tesselator/render.c b/cogl/tesselator/render.c
new file mode 100644
index 000000000..4f376f7f4
--- /dev/null
+++ b/cogl/tesselator/render.c
@@ -0,0 +1,498 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include
+#include "mesh.h"
+#include "tess.h"
+#include "render.h"
+
+#define TRUE 1
+#define FALSE 0
+
+/* This structure remembers the information we need about a primitive
+ * to be able to render it later, once we have determined which
+ * primitive is able to use the most triangles.
+ */
+struct FaceCount {
+ long size; /* number of triangles used */
+ GLUhalfEdge *eStart; /* edge where this primitive starts */
+ void (*render)(GLUtesselator *, GLUhalfEdge *, long);
+ /* routine to render this primitive */
+};
+
+static struct FaceCount MaximumFan( GLUhalfEdge *eOrig );
+static struct FaceCount MaximumStrip( GLUhalfEdge *eOrig );
+
+static void RenderFan( GLUtesselator *tess, GLUhalfEdge *eStart, long size );
+static void RenderStrip( GLUtesselator *tess, GLUhalfEdge *eStart, long size );
+static void RenderTriangle( GLUtesselator *tess, GLUhalfEdge *eStart,
+ long size );
+
+static void RenderMaximumFaceGroup( GLUtesselator *tess, GLUface *fOrig );
+static void RenderLonelyTriangles( GLUtesselator *tess, GLUface *head );
+
+
+
+/************************ Strips and Fans decomposition ******************/
+
+/* __gl_renderMesh( tess, mesh ) takes a mesh and breaks it into triangle
+ * fans, strips, and separate triangles. A substantial effort is made
+ * to use as few rendering primitives as possible (ie. to make the fans
+ * and strips as large as possible).
+ *
+ * The rendering output is provided as callbacks (see the api).
+ */
+void __gl_renderMesh( GLUtesselator *tess, GLUmesh *mesh )
+{
+ GLUface *f;
+
+ /* Make a list of separate triangles so we can render them all at once */
+ tess->lonelyTriList = NULL;
+
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+ f->marked = FALSE;
+ }
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+
+ /* We examine all faces in an arbitrary order. Whenever we find
+ * an unprocessed face F, we output a group of faces including F
+ * whose size is maximum.
+ */
+ if( f->inside && ! f->marked ) {
+ RenderMaximumFaceGroup( tess, f );
+ assert( f->marked );
+ }
+ }
+ if( tess->lonelyTriList != NULL ) {
+ RenderLonelyTriangles( tess, tess->lonelyTriList );
+ tess->lonelyTriList = NULL;
+ }
+}
+
+
+static void RenderMaximumFaceGroup( GLUtesselator *tess, GLUface *fOrig )
+{
+ /* We want to find the largest triangle fan or strip of unmarked faces
+ * which includes the given face fOrig. There are 3 possible fans
+ * passing through fOrig (one centered at each vertex), and 3 possible
+ * strips (one for each CCW permutation of the vertices). Our strategy
+ * is to try all of these, and take the primitive which uses the most
+ * triangles (a greedy approach).
+ */
+ GLUhalfEdge *e = fOrig->anEdge;
+ struct FaceCount max, newFace;
+
+ max.size = 1;
+ max.eStart = e;
+ max.render = &RenderTriangle;
+
+ if( ! tess->flagBoundary ) {
+ newFace = MaximumFan( e ); if( newFace.size > max.size ) { max = newFace; }
+ newFace = MaximumFan( e->Lnext ); if( newFace.size > max.size ) { max = newFace; }
+ newFace = MaximumFan( e->Lprev ); if( newFace.size > max.size ) { max = newFace; }
+
+ newFace = MaximumStrip( e ); if( newFace.size > max.size ) { max = newFace; }
+ newFace = MaximumStrip( e->Lnext ); if( newFace.size > max.size ) { max = newFace; }
+ newFace = MaximumStrip( e->Lprev ); if( newFace.size > max.size ) { max = newFace; }
+ }
+ (*(max.render))( tess, max.eStart, max.size );
+}
+
+
+/* Macros which keep track of faces we have marked temporarily, and allow
+ * us to backtrack when necessary. With triangle fans, this is not
+ * really necessary, since the only awkward case is a loop of triangles
+ * around a single origin vertex. However with strips the situation is
+ * more complicated, and we need a general tracking method like the
+ * one here.
+ */
+#define Marked(f) (! (f)->inside || (f)->marked)
+
+#define AddToTrail(f,t) ((f)->trail = (t), (t) = (f), (f)->marked = TRUE)
+
+#define FreeTrail(t) if( 1 ) { \
+ while( (t) != NULL ) { \
+ (t)->marked = FALSE; t = (t)->trail; \
+ } \
+ } else /* absorb trailing semicolon */
+
+
+
+static struct FaceCount MaximumFan( GLUhalfEdge *eOrig )
+{
+ /* eOrig->Lface is the face we want to render. We want to find the size
+ * of a maximal fan around eOrig->Org. To do this we just walk around
+ * the origin vertex as far as possible in both directions.
+ */
+ struct FaceCount newFace = { 0, NULL, &RenderFan };
+ GLUface *trail = NULL;
+ GLUhalfEdge *e;
+
+ for( e = eOrig; ! Marked( e->Lface ); e = e->Onext ) {
+ AddToTrail( e->Lface, trail );
+ ++newFace.size;
+ }
+ for( e = eOrig; ! Marked( e->Rface ); e = e->Oprev ) {
+ AddToTrail( e->Rface, trail );
+ ++newFace.size;
+ }
+ newFace.eStart = e;
+ /*LINTED*/
+ FreeTrail( trail );
+ return newFace;
+}
+
+
+#define IsEven(n) (((n) & 1) == 0)
+
+static struct FaceCount MaximumStrip( GLUhalfEdge *eOrig )
+{
+ /* Here we are looking for a maximal strip that contains the vertices
+ * eOrig->Org, eOrig->Dst, eOrig->Lnext->Dst (in that order or the
+ * reverse, such that all triangles are oriented CCW).
+ *
+ * Again we walk forward and backward as far as possible. However for
+ * strips there is a twist: to get CCW orientations, there must be
+ * an *even* number of triangles in the strip on one side of eOrig.
+ * We walk the strip starting on a side with an even number of triangles;
+ * if both side have an odd number, we are forced to shorten one side.
+ */
+ struct FaceCount newFace = { 0, NULL, &RenderStrip };
+ long headSize = 0, tailSize = 0;
+ GLUface *trail = NULL;
+ GLUhalfEdge *e, *eTail, *eHead;
+
+ for( e = eOrig; ! Marked( e->Lface ); ++tailSize, e = e->Onext ) {
+ AddToTrail( e->Lface, trail );
+ ++tailSize;
+ e = e->Dprev;
+ if( Marked( e->Lface )) break;
+ AddToTrail( e->Lface, trail );
+ }
+ eTail = e;
+
+ for( e = eOrig; ! Marked( e->Rface ); ++headSize, e = e->Dnext ) {
+ AddToTrail( e->Rface, trail );
+ ++headSize;
+ e = e->Oprev;
+ if( Marked( e->Rface )) break;
+ AddToTrail( e->Rface, trail );
+ }
+ eHead = e;
+
+ newFace.size = tailSize + headSize;
+ if( IsEven( tailSize )) {
+ newFace.eStart = eTail->Sym;
+ } else if( IsEven( headSize )) {
+ newFace.eStart = eHead;
+ } else {
+ /* Both sides have odd length, we must shorten one of them. In fact,
+ * we must start from eHead to guarantee inclusion of eOrig->Lface.
+ */
+ --newFace.size;
+ newFace.eStart = eHead->Onext;
+ }
+ /*LINTED*/
+ FreeTrail( trail );
+ return newFace;
+}
+
+
+static void RenderTriangle( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+ /* Just add the triangle to a triangle list, so we can render all
+ * the separate triangles at once.
+ */
+ assert( size == 1 );
+ AddToTrail( e->Lface, tess->lonelyTriList );
+}
+
+
+static void RenderLonelyTriangles( GLUtesselator *tess, GLUface *f )
+{
+ /* Now we render all the separate triangles which could not be
+ * grouped into a triangle fan or strip.
+ */
+ GLUhalfEdge *e;
+ int newState;
+ int edgeState = -1; /* force edge state output for first vertex */
+
+ CALL_BEGIN_OR_BEGIN_DATA( GL_TRIANGLES );
+
+ for( ; f != NULL; f = f->trail ) {
+ /* Loop once for each edge (there will always be 3 edges) */
+
+ e = f->anEdge;
+ do {
+ if( tess->flagBoundary ) {
+ /* Set the "edge state" to TRUE just before we output the
+ * first vertex of each edge on the polygon boundary.
+ */
+ newState = ! e->Rface->inside;
+ if( edgeState != newState ) {
+ edgeState = newState;
+ CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA( edgeState );
+ }
+ }
+ CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+
+ e = e->Lnext;
+ } while( e != f->anEdge );
+ }
+ CALL_END_OR_END_DATA();
+}
+
+
+static void RenderFan( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+ /* Render as many CCW triangles as possible in a fan starting from
+ * edge "e". The fan *should* contain exactly "size" triangles
+ * (otherwise we've goofed up somewhere).
+ */
+ CALL_BEGIN_OR_BEGIN_DATA( GL_TRIANGLE_FAN );
+ CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+ CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data );
+
+ while( ! Marked( e->Lface )) {
+ e->Lface->marked = TRUE;
+ --size;
+ e = e->Onext;
+ CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data );
+ }
+
+ assert( size == 0 );
+ CALL_END_OR_END_DATA();
+}
+
+
+static void RenderStrip( GLUtesselator *tess, GLUhalfEdge *e, long size )
+{
+ /* Render as many CCW triangles as possible in a strip starting from
+ * edge "e". The strip *should* contain exactly "size" triangles
+ * (otherwise we've goofed up somewhere).
+ */
+ CALL_BEGIN_OR_BEGIN_DATA( GL_TRIANGLE_STRIP );
+ CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+ CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data );
+
+ while( ! Marked( e->Lface )) {
+ e->Lface->marked = TRUE;
+ --size;
+ e = e->Dprev;
+ CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+ if( Marked( e->Lface )) break;
+
+ e->Lface->marked = TRUE;
+ --size;
+ e = e->Onext;
+ CALL_VERTEX_OR_VERTEX_DATA( e->Dst->data );
+ }
+
+ assert( size == 0 );
+ CALL_END_OR_END_DATA();
+}
+
+
+/************************ Boundary contour decomposition ******************/
+
+/* __gl_renderBoundary( tess, mesh ) takes a mesh, and outputs one
+ * contour for each face marked "inside". The rendering output is
+ * provided as callbacks (see the api).
+ */
+void __gl_renderBoundary( GLUtesselator *tess, GLUmesh *mesh )
+{
+ GLUface *f;
+ GLUhalfEdge *e;
+
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = f->next ) {
+ if( f->inside ) {
+ CALL_BEGIN_OR_BEGIN_DATA( GL_LINE_LOOP );
+ e = f->anEdge;
+ do {
+ CALL_VERTEX_OR_VERTEX_DATA( e->Org->data );
+ e = e->Lnext;
+ } while( e != f->anEdge );
+ CALL_END_OR_END_DATA();
+ }
+ }
+}
+
+
+/************************ Quick-and-dirty decomposition ******************/
+
+#define SIGN_INCONSISTENT 2
+
+static int ComputeNormal( GLUtesselator *tess, GLdouble norm[3], int check )
+/*
+ * If check==FALSE, we compute the polygon normal and place it in norm[].
+ * If check==TRUE, we check that each triangle in the fan from v0 has a
+ * consistent orientation with respect to norm[]. If triangles are
+ * consistently oriented CCW, return 1; if CW, return -1; if all triangles
+ * are degenerate return 0; otherwise (no consistent orientation) return
+ * SIGN_INCONSISTENT.
+ */
+{
+ CachedVertex *v0 = tess->cache;
+ CachedVertex *vn = v0 + tess->cacheCount;
+ CachedVertex *vc;
+ GLdouble dot, xc, yc, zc, xp, yp, zp, n[3];
+ int sign = 0;
+
+ /* Find the polygon normal. It is important to get a reasonable
+ * normal even when the polygon is self-intersecting (eg. a bowtie).
+ * Otherwise, the computed normal could be very tiny, but perpendicular
+ * to the true plane of the polygon due to numerical noise. Then all
+ * the triangles would appear to be degenerate and we would incorrectly
+ * decompose the polygon as a fan (or simply not render it at all).
+ *
+ * We use a sum-of-triangles normal algorithm rather than the more
+ * efficient sum-of-trapezoids method (used in CheckOrientation()
+ * in normal.c). This lets us explicitly reverse the signed area
+ * of some triangles to get a reasonable normal in the self-intersecting
+ * case.
+ */
+ if( ! check ) {
+ norm[0] = norm[1] = norm[2] = 0.0;
+ }
+
+ vc = v0 + 1;
+ xc = vc->coords[0] - v0->coords[0];
+ yc = vc->coords[1] - v0->coords[1];
+ zc = vc->coords[2] - v0->coords[2];
+ while( ++vc < vn ) {
+ xp = xc; yp = yc; zp = zc;
+ xc = vc->coords[0] - v0->coords[0];
+ yc = vc->coords[1] - v0->coords[1];
+ zc = vc->coords[2] - v0->coords[2];
+
+ /* Compute (vp - v0) cross (vc - v0) */
+ n[0] = yp*zc - zp*yc;
+ n[1] = zp*xc - xp*zc;
+ n[2] = xp*yc - yp*xc;
+
+ dot = n[0]*norm[0] + n[1]*norm[1] + n[2]*norm[2];
+ if( ! check ) {
+ /* Reverse the contribution of back-facing triangles to get
+ * a reasonable normal for self-intersecting polygons (see above)
+ */
+ if( dot >= 0 ) {
+ norm[0] += n[0]; norm[1] += n[1]; norm[2] += n[2];
+ } else {
+ norm[0] -= n[0]; norm[1] -= n[1]; norm[2] -= n[2];
+ }
+ } else if( dot != 0 ) {
+ /* Check the new orientation for consistency with previous triangles */
+ if( dot > 0 ) {
+ if( sign < 0 ) return SIGN_INCONSISTENT;
+ sign = 1;
+ } else {
+ if( sign > 0 ) return SIGN_INCONSISTENT;
+ sign = -1;
+ }
+ }
+ }
+ return sign;
+}
+
+/* __gl_renderCache( tess ) takes a single contour and tries to render it
+ * as a triangle fan. This handles convex polygons, as well as some
+ * non-convex polygons if we get lucky.
+ *
+ * Returns TRUE if the polygon was successfully rendered. The rendering
+ * output is provided as callbacks (see the api).
+ */
+GLboolean __gl_renderCache( GLUtesselator *tess )
+{
+ CachedVertex *v0 = tess->cache;
+ CachedVertex *vn = v0 + tess->cacheCount;
+ CachedVertex *vc;
+ GLdouble norm[3];
+ int sign;
+
+ if( tess->cacheCount < 3 ) {
+ /* Degenerate contour -- no output */
+ return TRUE;
+ }
+
+ norm[0] = tess->normal[0];
+ norm[1] = tess->normal[1];
+ norm[2] = tess->normal[2];
+ if( norm[0] == 0 && norm[1] == 0 && norm[2] == 0 ) {
+ ComputeNormal( tess, norm, FALSE );
+ }
+
+ sign = ComputeNormal( tess, norm, TRUE );
+ if( sign == SIGN_INCONSISTENT ) {
+ /* Fan triangles did not have a consistent orientation */
+ return FALSE;
+ }
+ if( sign == 0 ) {
+ /* All triangles were degenerate */
+ return TRUE;
+ }
+
+ /* Make sure we do the right thing for each winding rule */
+ switch( tess->windingRule ) {
+ case GLU_TESS_WINDING_ODD:
+ case GLU_TESS_WINDING_NONZERO:
+ break;
+ case GLU_TESS_WINDING_POSITIVE:
+ if( sign < 0 ) return TRUE;
+ break;
+ case GLU_TESS_WINDING_NEGATIVE:
+ if( sign > 0 ) return TRUE;
+ break;
+ case GLU_TESS_WINDING_ABS_GEQ_TWO:
+ return TRUE;
+ }
+
+ CALL_BEGIN_OR_BEGIN_DATA( tess->boundaryOnly ? GL_LINE_LOOP
+ : (tess->cacheCount > 3) ? GL_TRIANGLE_FAN
+ : GL_TRIANGLES );
+
+ CALL_VERTEX_OR_VERTEX_DATA( v0->data );
+ if( sign > 0 ) {
+ for( vc = v0+1; vc < vn; ++vc ) {
+ CALL_VERTEX_OR_VERTEX_DATA( vc->data );
+ }
+ } else {
+ for( vc = vn-1; vc > v0; --vc ) {
+ CALL_VERTEX_OR_VERTEX_DATA( vc->data );
+ }
+ }
+ CALL_END_OR_END_DATA();
+ return TRUE;
+}
diff --git a/cogl/tesselator/render.h b/cogl/tesselator/render.h
new file mode 100644
index 000000000..a298c9a94
--- /dev/null
+++ b/cogl/tesselator/render.h
@@ -0,0 +1,52 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __render_h_
+#define __render_h_
+
+#include "mesh.h"
+
+/* __gl_renderMesh( tess, mesh ) takes a mesh and breaks it into triangle
+ * fans, strips, and separate triangles. A substantial effort is made
+ * to use as few rendering primitives as possible (ie. to make the fans
+ * and strips as large as possible).
+ *
+ * The rendering output is provided as callbacks (see the api).
+ */
+void __gl_renderMesh( GLUtesselator *tess, GLUmesh *mesh );
+void __gl_renderBoundary( GLUtesselator *tess, GLUmesh *mesh );
+
+GLboolean __gl_renderCache( GLUtesselator *tess );
+
+#endif
diff --git a/cogl/tesselator/sweep.c b/cogl/tesselator/sweep.c
new file mode 100644
index 000000000..744be6b47
--- /dev/null
+++ b/cogl/tesselator/sweep.c
@@ -0,0 +1,1357 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include
+#include /* longjmp */
+#include /* LONG_MAX */
+
+#include "mesh.h"
+#include "geom.h"
+#include "tess.h"
+#include "dict.h"
+#include "priorityq.h"
+#include "memalloc.h"
+#include "sweep.h"
+
+#define TRUE 1
+#define FALSE 0
+
+#ifdef FOR_TRITE_TEST_PROGRAM
+extern void DebugEvent( GLUtesselator *tess );
+#else
+#define DebugEvent( tess )
+#endif
+
+/*
+ * Invariants for the Edge Dictionary.
+ * - each pair of adjacent edges e2=Succ(e1) satisfies EdgeLeq(e1,e2)
+ * at any valid location of the sweep event
+ * - if EdgeLeq(e2,e1) as well (at any valid sweep event), then e1 and e2
+ * share a common endpoint
+ * - for each e, e->Dst has been processed, but not e->Org
+ * - each edge e satisfies VertLeq(e->Dst,event) && VertLeq(event,e->Org)
+ * where "event" is the current sweep line event.
+ * - no edge e has zero length
+ *
+ * Invariants for the Mesh (the processed portion).
+ * - the portion of the mesh left of the sweep line is a planar graph,
+ * ie. there is *some* way to embed it in the plane
+ * - no processed edge has zero length
+ * - no two processed vertices have identical coordinates
+ * - each "inside" region is monotone, ie. can be broken into two chains
+ * of monotonically increasing vertices according to VertLeq(v1,v2)
+ * - a non-invariant: these chains may intersect (very slightly)
+ *
+ * Invariants for the Sweep.
+ * - if none of the edges incident to the event vertex have an activeRegion
+ * (ie. none of these edges are in the edge dictionary), then the vertex
+ * has only right-going edges.
+ * - if an edge is marked "fixUpperEdge" (it is a temporary edge introduced
+ * by ConnectRightVertex), then it is the only right-going edge from
+ * its associated vertex. (This says that these edges exist only
+ * when it is necessary.)
+ */
+
+#undef MAX
+#undef MIN
+#define MAX(x,y) ((x) >= (y) ? (x) : (y))
+#define MIN(x,y) ((x) <= (y) ? (x) : (y))
+
+/* When we merge two edges into one, we need to compute the combined
+ * winding of the new edge.
+ */
+#define AddWinding(eDst,eSrc) (eDst->winding += eSrc->winding, \
+ eDst->Sym->winding += eSrc->Sym->winding)
+
+static void SweepEvent( GLUtesselator *tess, GLUvertex *vEvent );
+static void WalkDirtyRegions( GLUtesselator *tess, ActiveRegion *regUp );
+static int CheckForRightSplice( GLUtesselator *tess, ActiveRegion *regUp );
+
+static int EdgeLeq( GLUtesselator *tess, ActiveRegion *reg1,
+ ActiveRegion *reg2 )
+/*
+ * Both edges must be directed from right to left (this is the canonical
+ * direction for the upper edge of each region).
+ *
+ * The strategy is to evaluate a "t" value for each edge at the
+ * current sweep line position, given by tess->event. The calculations
+ * are designed to be very stable, but of course they are not perfect.
+ *
+ * Special case: if both edge destinations are at the sweep event,
+ * we sort the edges by slope (they would otherwise compare equally).
+ */
+{
+ GLUvertex *event = tess->event;
+ GLUhalfEdge *e1, *e2;
+ GLdouble t1, t2;
+
+ e1 = reg1->eUp;
+ e2 = reg2->eUp;
+
+ if( e1->Dst == event ) {
+ if( e2->Dst == event ) {
+ /* Two edges right of the sweep line which meet at the sweep event.
+ * Sort them by slope.
+ */
+ if( VertLeq( e1->Org, e2->Org )) {
+ return EdgeSign( e2->Dst, e1->Org, e2->Org ) <= 0;
+ }
+ return EdgeSign( e1->Dst, e2->Org, e1->Org ) >= 0;
+ }
+ return EdgeSign( e2->Dst, event, e2->Org ) <= 0;
+ }
+ if( e2->Dst == event ) {
+ return EdgeSign( e1->Dst, event, e1->Org ) >= 0;
+ }
+
+ /* General case - compute signed distance *from* e1, e2 to event */
+ t1 = EdgeEval( e1->Dst, event, e1->Org );
+ t2 = EdgeEval( e2->Dst, event, e2->Org );
+ return (t1 >= t2);
+}
+
+
+static void DeleteRegion( GLUtesselator *tess, ActiveRegion *reg )
+{
+ if( reg->fixUpperEdge ) {
+ /* It was created with zero winding number, so it better be
+ * deleted with zero winding number (ie. it better not get merged
+ * with a real edge).
+ */
+ assert( reg->eUp->winding == 0 );
+ }
+ reg->eUp->activeRegion = NULL;
+ dictDelete( tess->dict, reg->nodeUp ); /* __gl_dictListDelete */
+ memFree( reg );
+}
+
+
+static int FixUpperEdge( ActiveRegion *reg, GLUhalfEdge *newEdge )
+/*
+ * Replace an upper edge which needs fixing (see ConnectRightVertex).
+ */
+{
+ assert( reg->fixUpperEdge );
+ if ( !__gl_meshDelete( reg->eUp ) ) return 0;
+ reg->fixUpperEdge = FALSE;
+ reg->eUp = newEdge;
+ newEdge->activeRegion = reg;
+
+ return 1;
+}
+
+static ActiveRegion *TopLeftRegion( ActiveRegion *reg )
+{
+ GLUvertex *org = reg->eUp->Org;
+ GLUhalfEdge *e;
+
+ /* Find the region above the uppermost edge with the same origin */
+ do {
+ reg = RegionAbove( reg );
+ } while( reg->eUp->Org == org );
+
+ /* If the edge above was a temporary edge introduced by ConnectRightVertex,
+ * now is the time to fix it.
+ */
+ if( reg->fixUpperEdge ) {
+ e = __gl_meshConnect( RegionBelow(reg)->eUp->Sym, reg->eUp->Lnext );
+ if (e == NULL) return NULL;
+ if ( !FixUpperEdge( reg, e ) ) return NULL;
+ reg = RegionAbove( reg );
+ }
+ return reg;
+}
+
+static ActiveRegion *TopRightRegion( ActiveRegion *reg )
+{
+ GLUvertex *dst = reg->eUp->Dst;
+
+ /* Find the region above the uppermost edge with the same destination */
+ do {
+ reg = RegionAbove( reg );
+ } while( reg->eUp->Dst == dst );
+ return reg;
+}
+
+static ActiveRegion *AddRegionBelow( GLUtesselator *tess,
+ ActiveRegion *regAbove,
+ GLUhalfEdge *eNewUp )
+/*
+ * Add a new active region to the sweep line, *somewhere* below "regAbove"
+ * (according to where the new edge belongs in the sweep-line dictionary).
+ * The upper edge of the new region will be "eNewUp".
+ * Winding number and "inside" flag are not updated.
+ */
+{
+ ActiveRegion *regNew = (ActiveRegion *)memAlloc( sizeof( ActiveRegion ));
+ if (regNew == NULL) longjmp(tess->env,1);
+
+ regNew->eUp = eNewUp;
+ /* __gl_dictListInsertBefore */
+ regNew->nodeUp = dictInsertBefore( tess->dict, regAbove->nodeUp, regNew );
+ if (regNew->nodeUp == NULL) longjmp(tess->env,1);
+ regNew->fixUpperEdge = FALSE;
+ regNew->sentinel = FALSE;
+ regNew->dirty = FALSE;
+
+ eNewUp->activeRegion = regNew;
+ return regNew;
+}
+
+static GLboolean IsWindingInside( GLUtesselator *tess, int n )
+{
+ switch( tess->windingRule ) {
+ case GLU_TESS_WINDING_ODD:
+ return (n & 1);
+ case GLU_TESS_WINDING_NONZERO:
+ return (n != 0);
+ case GLU_TESS_WINDING_POSITIVE:
+ return (n > 0);
+ case GLU_TESS_WINDING_NEGATIVE:
+ return (n < 0);
+ case GLU_TESS_WINDING_ABS_GEQ_TWO:
+ return (n >= 2) || (n <= -2);
+ }
+ /*LINTED*/
+ assert( FALSE );
+ /*NOTREACHED*/
+ return GL_FALSE; /* avoid compiler complaints */
+}
+
+
+static void ComputeWinding( GLUtesselator *tess, ActiveRegion *reg )
+{
+ reg->windingNumber = RegionAbove(reg)->windingNumber + reg->eUp->winding;
+ reg->inside = IsWindingInside( tess, reg->windingNumber );
+}
+
+
+static void FinishRegion( GLUtesselator *tess, ActiveRegion *reg )
+/*
+ * Delete a region from the sweep line. This happens when the upper
+ * and lower chains of a region meet (at a vertex on the sweep line).
+ * The "inside" flag is copied to the appropriate mesh face (we could
+ * not do this before -- since the structure of the mesh is always
+ * changing, this face may not have even existed until now).
+ */
+{
+ GLUhalfEdge *e = reg->eUp;
+ GLUface *f = e->Lface;
+
+ f->inside = reg->inside;
+ f->anEdge = e; /* optimization for __gl_meshTessellateMonoRegion() */
+ DeleteRegion( tess, reg );
+}
+
+
+static GLUhalfEdge *FinishLeftRegions( GLUtesselator *tess,
+ ActiveRegion *regFirst, ActiveRegion *regLast )
+/*
+ * We are given a vertex with one or more left-going edges. All affected
+ * edges should be in the edge dictionary. Starting at regFirst->eUp,
+ * we walk down deleting all regions where both edges have the same
+ * origin vOrg. At the same time we copy the "inside" flag from the
+ * active region to the face, since at this point each face will belong
+ * to at most one region (this was not necessarily true until this point
+ * in the sweep). The walk stops at the region above regLast; if regLast
+ * is NULL we walk as far as possible. At the same time we relink the
+ * mesh if necessary, so that the ordering of edges around vOrg is the
+ * same as in the dictionary.
+ */
+{
+ ActiveRegion *reg, *regPrev;
+ GLUhalfEdge *e, *ePrev;
+
+ regPrev = regFirst;
+ ePrev = regFirst->eUp;
+ while( regPrev != regLast ) {
+ regPrev->fixUpperEdge = FALSE; /* placement was OK */
+ reg = RegionBelow( regPrev );
+ e = reg->eUp;
+ if( e->Org != ePrev->Org ) {
+ if( ! reg->fixUpperEdge ) {
+ /* Remove the last left-going edge. Even though there are no further
+ * edges in the dictionary with this origin, there may be further
+ * such edges in the mesh (if we are adding left edges to a vertex
+ * that has already been processed). Thus it is important to call
+ * FinishRegion rather than just DeleteRegion.
+ */
+ FinishRegion( tess, regPrev );
+ break;
+ }
+ /* If the edge below was a temporary edge introduced by
+ * ConnectRightVertex, now is the time to fix it.
+ */
+ e = __gl_meshConnect( ePrev->Lprev, e->Sym );
+ if (e == NULL) longjmp(tess->env,1);
+ if ( !FixUpperEdge( reg, e ) ) longjmp(tess->env,1);
+ }
+
+ /* Relink edges so that ePrev->Onext == e */
+ if( ePrev->Onext != e ) {
+ if ( !__gl_meshSplice( e->Oprev, e ) ) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( ePrev, e ) ) longjmp(tess->env,1);
+ }
+ FinishRegion( tess, regPrev ); /* may change reg->eUp */
+ ePrev = reg->eUp;
+ regPrev = reg;
+ }
+ return ePrev;
+}
+
+
+static void AddRightEdges( GLUtesselator *tess, ActiveRegion *regUp,
+ GLUhalfEdge *eFirst, GLUhalfEdge *eLast, GLUhalfEdge *eTopLeft,
+ GLboolean cleanUp )
+/*
+ * Purpose: insert right-going edges into the edge dictionary, and update
+ * winding numbers and mesh connectivity appropriately. All right-going
+ * edges share a common origin vOrg. Edges are inserted CCW starting at
+ * eFirst; the last edge inserted is eLast->Oprev. If vOrg has any
+ * left-going edges already processed, then eTopLeft must be the edge
+ * such that an imaginary upward vertical segment from vOrg would be
+ * contained between eTopLeft->Oprev and eTopLeft; otherwise eTopLeft
+ * should be NULL.
+ */
+{
+ ActiveRegion *reg, *regPrev;
+ GLUhalfEdge *e, *ePrev;
+ int firstTime = TRUE;
+
+ /* Insert the new right-going edges in the dictionary */
+ e = eFirst;
+ do {
+ assert( VertLeq( e->Org, e->Dst ));
+ AddRegionBelow( tess, regUp, e->Sym );
+ e = e->Onext;
+ } while ( e != eLast );
+
+ /* Walk *all* right-going edges from e->Org, in the dictionary order,
+ * updating the winding numbers of each region, and re-linking the mesh
+ * edges to match the dictionary ordering (if necessary).
+ */
+ if( eTopLeft == NULL ) {
+ eTopLeft = RegionBelow( regUp )->eUp->Rprev;
+ }
+ regPrev = regUp;
+ ePrev = eTopLeft;
+ for( ;; ) {
+ reg = RegionBelow( regPrev );
+ e = reg->eUp->Sym;
+ if( e->Org != ePrev->Org ) break;
+
+ if( e->Onext != ePrev ) {
+ /* Unlink e from its current position, and relink below ePrev */
+ if ( !__gl_meshSplice( e->Oprev, e ) ) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( ePrev->Oprev, e ) ) longjmp(tess->env,1);
+ }
+ /* Compute the winding number and "inside" flag for the new regions */
+ reg->windingNumber = regPrev->windingNumber - e->winding;
+ reg->inside = IsWindingInside( tess, reg->windingNumber );
+
+ /* Check for two outgoing edges with same slope -- process these
+ * before any intersection tests (see example in __gl_computeInterior).
+ */
+ regPrev->dirty = TRUE;
+ if( ! firstTime && CheckForRightSplice( tess, regPrev )) {
+ AddWinding( e, ePrev );
+ DeleteRegion( tess, regPrev );
+ if ( !__gl_meshDelete( ePrev ) ) longjmp(tess->env,1);
+ }
+ firstTime = FALSE;
+ regPrev = reg;
+ ePrev = e;
+ }
+ regPrev->dirty = TRUE;
+ assert( regPrev->windingNumber - e->winding == reg->windingNumber );
+
+ if( cleanUp ) {
+ /* Check for intersections between newly adjacent edges. */
+ WalkDirtyRegions( tess, regPrev );
+ }
+}
+
+
+static void CallCombine( GLUtesselator *tess, GLUvertex *isect,
+ void *data[4], GLfloat weights[4], int needed )
+{
+ GLdouble coords[3];
+
+ /* Copy coord data in case the callback changes it. */
+ coords[0] = isect->coords[0];
+ coords[1] = isect->coords[1];
+ coords[2] = isect->coords[2];
+
+ isect->data = NULL;
+ CALL_COMBINE_OR_COMBINE_DATA( coords, data, weights, &isect->data );
+ if( isect->data == NULL ) {
+ if( ! needed ) {
+ isect->data = data[0];
+ } else if( ! tess->fatalError ) {
+ /* The only way fatal error is when two edges are found to intersect,
+ * but the user has not provided the callback necessary to handle
+ * generated intersection points.
+ */
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_NEED_COMBINE_CALLBACK );
+ tess->fatalError = TRUE;
+ }
+ }
+}
+
+static void SpliceMergeVertices( GLUtesselator *tess, GLUhalfEdge *e1,
+ GLUhalfEdge *e2 )
+/*
+ * Two vertices with idential coordinates are combined into one.
+ * e1->Org is kept, while e2->Org is discarded.
+ */
+{
+ void *data[4] = { NULL, NULL, NULL, NULL };
+ GLfloat weights[4] = { 0.5, 0.5, 0.0, 0.0 };
+
+ data[0] = e1->Org->data;
+ data[1] = e2->Org->data;
+ CallCombine( tess, e1->Org, data, weights, FALSE );
+ if ( !__gl_meshSplice( e1, e2 ) ) longjmp(tess->env,1);
+}
+
+static void VertexWeights( GLUvertex *isect, GLUvertex *org, GLUvertex *dst,
+ GLfloat *weights )
+/*
+ * Find some weights which describe how the intersection vertex is
+ * a linear combination of "org" and "dest". Each of the two edges
+ * which generated "isect" is allocated 50% of the weight; each edge
+ * splits the weight between its org and dst according to the
+ * relative distance to "isect".
+ */
+{
+ GLdouble t1 = VertL1dist( org, isect );
+ GLdouble t2 = VertL1dist( dst, isect );
+
+ weights[0] = 0.5 * t2 / (t1 + t2);
+ weights[1] = 0.5 * t1 / (t1 + t2);
+ isect->coords[0] += weights[0]*org->coords[0] + weights[1]*dst->coords[0];
+ isect->coords[1] += weights[0]*org->coords[1] + weights[1]*dst->coords[1];
+ isect->coords[2] += weights[0]*org->coords[2] + weights[1]*dst->coords[2];
+}
+
+
+static void GetIntersectData( GLUtesselator *tess, GLUvertex *isect,
+ GLUvertex *orgUp, GLUvertex *dstUp,
+ GLUvertex *orgLo, GLUvertex *dstLo )
+/*
+ * We've computed a new intersection point, now we need a "data" pointer
+ * from the user so that we can refer to this new vertex in the
+ * rendering callbacks.
+ */
+{
+ void *data[4];
+ GLfloat weights[4];
+
+ data[0] = orgUp->data;
+ data[1] = dstUp->data;
+ data[2] = orgLo->data;
+ data[3] = dstLo->data;
+
+ isect->coords[0] = isect->coords[1] = isect->coords[2] = 0;
+ VertexWeights( isect, orgUp, dstUp, &weights[0] );
+ VertexWeights( isect, orgLo, dstLo, &weights[2] );
+
+ CallCombine( tess, isect, data, weights, TRUE );
+}
+
+static int CheckForRightSplice( GLUtesselator *tess, ActiveRegion *regUp )
+/*
+ * Check the upper and lower edge of "regUp", to make sure that the
+ * eUp->Org is above eLo, or eLo->Org is below eUp (depending on which
+ * origin is leftmost).
+ *
+ * The main purpose is to splice right-going edges with the same
+ * dest vertex and nearly identical slopes (ie. we can't distinguish
+ * the slopes numerically). However the splicing can also help us
+ * to recover from numerical errors. For example, suppose at one
+ * point we checked eUp and eLo, and decided that eUp->Org is barely
+ * above eLo. Then later, we split eLo into two edges (eg. from
+ * a splice operation like this one). This can change the result of
+ * our test so that now eUp->Org is incident to eLo, or barely below it.
+ * We must correct this condition to maintain the dictionary invariants.
+ *
+ * One possibility is to check these edges for intersection again
+ * (ie. CheckForIntersect). This is what we do if possible. However
+ * CheckForIntersect requires that tess->event lies between eUp and eLo,
+ * so that it has something to fall back on when the intersection
+ * calculation gives us an unusable answer. So, for those cases where
+ * we can't check for intersection, this routine fixes the problem
+ * by just splicing the offending vertex into the other edge.
+ * This is a guaranteed solution, no matter how degenerate things get.
+ * Basically this is a combinatorial solution to a numerical problem.
+ */
+{
+ ActiveRegion *regLo = RegionBelow(regUp);
+ GLUhalfEdge *eUp = regUp->eUp;
+ GLUhalfEdge *eLo = regLo->eUp;
+
+ if( VertLeq( eUp->Org, eLo->Org )) {
+ if( EdgeSign( eLo->Dst, eUp->Org, eLo->Org ) > 0 ) return FALSE;
+
+ /* eUp->Org appears to be below eLo */
+ if( ! VertEq( eUp->Org, eLo->Org )) {
+ /* Splice eUp->Org into eLo */
+ if ( __gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eUp, eLo->Oprev ) ) longjmp(tess->env,1);
+ regUp->dirty = regLo->dirty = TRUE;
+
+ } else if( eUp->Org != eLo->Org ) {
+ /* merge the two vertices, discarding eUp->Org */
+ pqDelete( tess->pq, eUp->Org->pqHandle ); /* __gl_pqSortDelete */
+ SpliceMergeVertices( tess, eLo->Oprev, eUp );
+ }
+ } else {
+ if( EdgeSign( eUp->Dst, eLo->Org, eUp->Org ) < 0 ) return FALSE;
+
+ /* eLo->Org appears to be above eUp, so splice eLo->Org into eUp */
+ RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
+ if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eLo->Oprev, eUp ) ) longjmp(tess->env,1);
+ }
+ return TRUE;
+}
+
+static int CheckForLeftSplice( GLUtesselator *tess, ActiveRegion *regUp )
+/*
+ * Check the upper and lower edge of "regUp", to make sure that the
+ * eUp->Dst is above eLo, or eLo->Dst is below eUp (depending on which
+ * destination is rightmost).
+ *
+ * Theoretically, this should always be true. However, splitting an edge
+ * into two pieces can change the results of previous tests. For example,
+ * suppose at one point we checked eUp and eLo, and decided that eUp->Dst
+ * is barely above eLo. Then later, we split eLo into two edges (eg. from
+ * a splice operation like this one). This can change the result of
+ * the test so that now eUp->Dst is incident to eLo, or barely below it.
+ * We must correct this condition to maintain the dictionary invariants
+ * (otherwise new edges might get inserted in the wrong place in the
+ * dictionary, and bad stuff will happen).
+ *
+ * We fix the problem by just splicing the offending vertex into the
+ * other edge.
+ */
+{
+ ActiveRegion *regLo = RegionBelow(regUp);
+ GLUhalfEdge *eUp = regUp->eUp;
+ GLUhalfEdge *eLo = regLo->eUp;
+ GLUhalfEdge *e;
+
+ assert( ! VertEq( eUp->Dst, eLo->Dst ));
+
+ if( VertLeq( eUp->Dst, eLo->Dst )) {
+ if( EdgeSign( eUp->Dst, eLo->Dst, eUp->Org ) < 0 ) return FALSE;
+
+ /* eLo->Dst is above eUp, so splice eLo->Dst into eUp */
+ RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
+ e = __gl_meshSplitEdge( eUp );
+ if (e == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eLo->Sym, e ) ) longjmp(tess->env,1);
+ e->Lface->inside = regUp->inside;
+ } else {
+ if( EdgeSign( eLo->Dst, eUp->Dst, eLo->Org ) > 0 ) return FALSE;
+
+ /* eUp->Dst is below eLo, so splice eUp->Dst into eLo */
+ regUp->dirty = regLo->dirty = TRUE;
+ e = __gl_meshSplitEdge( eLo );
+ if (e == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eUp->Lnext, eLo->Sym ) ) longjmp(tess->env,1);
+ e->Rface->inside = regUp->inside;
+ }
+ return TRUE;
+}
+
+
+static int CheckForIntersect( GLUtesselator *tess, ActiveRegion *regUp )
+/*
+ * Check the upper and lower edges of the given region to see if
+ * they intersect. If so, create the intersection and add it
+ * to the data structures.
+ *
+ * Returns TRUE if adding the new intersection resulted in a recursive
+ * call to AddRightEdges(); in this case all "dirty" regions have been
+ * checked for intersections, and possibly regUp has been deleted.
+ */
+{
+ ActiveRegion *regLo = RegionBelow(regUp);
+ GLUhalfEdge *eUp = regUp->eUp;
+ GLUhalfEdge *eLo = regLo->eUp;
+ GLUvertex *orgUp = eUp->Org;
+ GLUvertex *orgLo = eLo->Org;
+ GLUvertex *dstUp = eUp->Dst;
+ GLUvertex *dstLo = eLo->Dst;
+ GLdouble tMinUp, tMaxLo;
+ GLUvertex isect, *orgMin;
+ GLUhalfEdge *e;
+
+ assert( ! VertEq( dstLo, dstUp ));
+ assert( EdgeSign( dstUp, tess->event, orgUp ) <= 0 );
+ assert( EdgeSign( dstLo, tess->event, orgLo ) >= 0 );
+ assert( orgUp != tess->event && orgLo != tess->event );
+ assert( ! regUp->fixUpperEdge && ! regLo->fixUpperEdge );
+
+ if( orgUp == orgLo ) return FALSE; /* right endpoints are the same */
+
+ tMinUp = MIN( orgUp->t, dstUp->t );
+ tMaxLo = MAX( orgLo->t, dstLo->t );
+ if( tMinUp > tMaxLo ) return FALSE; /* t ranges do not overlap */
+
+ if( VertLeq( orgUp, orgLo )) {
+ if( EdgeSign( dstLo, orgUp, orgLo ) > 0 ) return FALSE;
+ } else {
+ if( EdgeSign( dstUp, orgLo, orgUp ) < 0 ) return FALSE;
+ }
+
+ /* At this point the edges intersect, at least marginally */
+ DebugEvent( tess );
+
+ __gl_edgeIntersect( dstUp, orgUp, dstLo, orgLo, &isect );
+ /* The following properties are guaranteed: */
+ assert( MIN( orgUp->t, dstUp->t ) <= isect.t );
+ assert( isect.t <= MAX( orgLo->t, dstLo->t ));
+ assert( MIN( dstLo->s, dstUp->s ) <= isect.s );
+ assert( isect.s <= MAX( orgLo->s, orgUp->s ));
+
+ if( VertLeq( &isect, tess->event )) {
+ /* The intersection point lies slightly to the left of the sweep line,
+ * so move it until it''s slightly to the right of the sweep line.
+ * (If we had perfect numerical precision, this would never happen
+ * in the first place). The easiest and safest thing to do is
+ * replace the intersection by tess->event.
+ */
+ isect.s = tess->event->s;
+ isect.t = tess->event->t;
+ }
+ /* Similarly, if the computed intersection lies to the right of the
+ * rightmost origin (which should rarely happen), it can cause
+ * unbelievable inefficiency on sufficiently degenerate inputs.
+ * (If you have the test program, try running test54.d with the
+ * "X zoom" option turned on).
+ */
+ orgMin = VertLeq( orgUp, orgLo ) ? orgUp : orgLo;
+ if( VertLeq( orgMin, &isect )) {
+ isect.s = orgMin->s;
+ isect.t = orgMin->t;
+ }
+
+ if( VertEq( &isect, orgUp ) || VertEq( &isect, orgLo )) {
+ /* Easy case -- intersection at one of the right endpoints */
+ (void) CheckForRightSplice( tess, regUp );
+ return FALSE;
+ }
+
+ if( (! VertEq( dstUp, tess->event )
+ && EdgeSign( dstUp, tess->event, &isect ) >= 0)
+ || (! VertEq( dstLo, tess->event )
+ && EdgeSign( dstLo, tess->event, &isect ) <= 0 ))
+ {
+ /* Very unusual -- the new upper or lower edge would pass on the
+ * wrong side of the sweep event, or through it. This can happen
+ * due to very small numerical errors in the intersection calculation.
+ */
+ if( dstLo == tess->event ) {
+ /* Splice dstLo into eUp, and process the new region(s) */
+ if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eLo->Sym, eUp ) ) longjmp(tess->env,1);
+ regUp = TopLeftRegion( regUp );
+ if (regUp == NULL) longjmp(tess->env,1);
+ eUp = RegionBelow(regUp)->eUp;
+ FinishLeftRegions( tess, RegionBelow(regUp), regLo );
+ AddRightEdges( tess, regUp, eUp->Oprev, eUp, eUp, TRUE );
+ return TRUE;
+ }
+ if( dstUp == tess->event ) {
+ /* Splice dstUp into eLo, and process the new region(s) */
+ if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eUp->Lnext, eLo->Oprev ) ) longjmp(tess->env,1);
+ regLo = regUp;
+ regUp = TopRightRegion( regUp );
+ e = RegionBelow(regUp)->eUp->Rprev;
+ regLo->eUp = eLo->Oprev;
+ eLo = FinishLeftRegions( tess, regLo, NULL );
+ AddRightEdges( tess, regUp, eLo->Onext, eUp->Rprev, e, TRUE );
+ return TRUE;
+ }
+ /* Special case: called from ConnectRightVertex. If either
+ * edge passes on the wrong side of tess->event, split it
+ * (and wait for ConnectRightVertex to splice it appropriately).
+ */
+ if( EdgeSign( dstUp, tess->event, &isect ) >= 0 ) {
+ RegionAbove(regUp)->dirty = regUp->dirty = TRUE;
+ if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
+ eUp->Org->s = tess->event->s;
+ eUp->Org->t = tess->event->t;
+ }
+ if( EdgeSign( dstLo, tess->event, &isect ) <= 0 ) {
+ regUp->dirty = regLo->dirty = TRUE;
+ if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
+ eLo->Org->s = tess->event->s;
+ eLo->Org->t = tess->event->t;
+ }
+ /* leave the rest for ConnectRightVertex */
+ return FALSE;
+ }
+
+ /* General case -- split both edges, splice into new vertex.
+ * When we do the splice operation, the order of the arguments is
+ * arbitrary as far as correctness goes. However, when the operation
+ * creates a new face, the work done is proportional to the size of
+ * the new face. We expect the faces in the processed part of
+ * the mesh (ie. eUp->Lface) to be smaller than the faces in the
+ * unprocessed original contours (which will be eLo->Oprev->Lface).
+ */
+ if (__gl_meshSplitEdge( eUp->Sym ) == NULL) longjmp(tess->env,1);
+ if (__gl_meshSplitEdge( eLo->Sym ) == NULL) longjmp(tess->env,1);
+ if ( !__gl_meshSplice( eLo->Oprev, eUp ) ) longjmp(tess->env,1);
+ eUp->Org->s = isect.s;
+ eUp->Org->t = isect.t;
+ eUp->Org->pqHandle = pqInsert( tess->pq, eUp->Org ); /* __gl_pqSortInsert */
+ if (eUp->Org->pqHandle == LONG_MAX) {
+ pqDeletePriorityQ(tess->pq); /* __gl_pqSortDeletePriorityQ */
+ tess->pq = NULL;
+ longjmp(tess->env,1);
+ }
+ GetIntersectData( tess, eUp->Org, orgUp, dstUp, orgLo, dstLo );
+ RegionAbove(regUp)->dirty = regUp->dirty = regLo->dirty = TRUE;
+ return FALSE;
+}
+
+static void WalkDirtyRegions( GLUtesselator *tess, ActiveRegion *regUp )
+/*
+ * When the upper or lower edge of any region changes, the region is
+ * marked "dirty". This routine walks through all the dirty regions
+ * and makes sure that the dictionary invariants are satisfied
+ * (see the comments at the beginning of this file). Of course
+ * new dirty regions can be created as we make changes to restore
+ * the invariants.
+ */
+{
+ ActiveRegion *regLo = RegionBelow(regUp);
+ GLUhalfEdge *eUp, *eLo;
+
+ for( ;; ) {
+ /* Find the lowest dirty region (we walk from the bottom up). */
+ while( regLo->dirty ) {
+ regUp = regLo;
+ regLo = RegionBelow(regLo);
+ }
+ if( ! regUp->dirty ) {
+ regLo = regUp;
+ regUp = RegionAbove( regUp );
+ if( regUp == NULL || ! regUp->dirty ) {
+ /* We've walked all the dirty regions */
+ return;
+ }
+ }
+ regUp->dirty = FALSE;
+ eUp = regUp->eUp;
+ eLo = regLo->eUp;
+
+ if( eUp->Dst != eLo->Dst ) {
+ /* Check that the edge ordering is obeyed at the Dst vertices. */
+ if( CheckForLeftSplice( tess, regUp )) {
+
+ /* If the upper or lower edge was marked fixUpperEdge, then
+ * we no longer need it (since these edges are needed only for
+ * vertices which otherwise have no right-going edges).
+ */
+ if( regLo->fixUpperEdge ) {
+ DeleteRegion( tess, regLo );
+ if ( !__gl_meshDelete( eLo ) ) longjmp(tess->env,1);
+ regLo = RegionBelow( regUp );
+ eLo = regLo->eUp;
+ } else if( regUp->fixUpperEdge ) {
+ DeleteRegion( tess, regUp );
+ if ( !__gl_meshDelete( eUp ) ) longjmp(tess->env,1);
+ regUp = RegionAbove( regLo );
+ eUp = regUp->eUp;
+ }
+ }
+ }
+ if( eUp->Org != eLo->Org ) {
+ if( eUp->Dst != eLo->Dst
+ && ! regUp->fixUpperEdge && ! regLo->fixUpperEdge
+ && (eUp->Dst == tess->event || eLo->Dst == tess->event) )
+ {
+ /* When all else fails in CheckForIntersect(), it uses tess->event
+ * as the intersection location. To make this possible, it requires
+ * that tess->event lie between the upper and lower edges, and also
+ * that neither of these is marked fixUpperEdge (since in the worst
+ * case it might splice one of these edges into tess->event, and
+ * violate the invariant that fixable edges are the only right-going
+ * edge from their associated vertex).
+ */
+ if( CheckForIntersect( tess, regUp )) {
+ /* WalkDirtyRegions() was called recursively; we're done */
+ return;
+ }
+ } else {
+ /* Even though we can't use CheckForIntersect(), the Org vertices
+ * may violate the dictionary edge ordering. Check and correct this.
+ */
+ (void) CheckForRightSplice( tess, regUp );
+ }
+ }
+ if( eUp->Org == eLo->Org && eUp->Dst == eLo->Dst ) {
+ /* A degenerate loop consisting of only two edges -- delete it. */
+ AddWinding( eLo, eUp );
+ DeleteRegion( tess, regUp );
+ if ( !__gl_meshDelete( eUp ) ) longjmp(tess->env,1);
+ regUp = RegionAbove( regLo );
+ }
+ }
+}
+
+
+static void ConnectRightVertex( GLUtesselator *tess, ActiveRegion *regUp,
+ GLUhalfEdge *eBottomLeft )
+/*
+ * Purpose: connect a "right" vertex vEvent (one where all edges go left)
+ * to the unprocessed portion of the mesh. Since there are no right-going
+ * edges, two regions (one above vEvent and one below) are being merged
+ * into one. "regUp" is the upper of these two regions.
+ *
+ * There are two reasons for doing this (adding a right-going edge):
+ * - if the two regions being merged are "inside", we must add an edge
+ * to keep them separated (the combined region would not be monotone).
+ * - in any case, we must leave some record of vEvent in the dictionary,
+ * so that we can merge vEvent with features that we have not seen yet.
+ * For example, maybe there is a vertical edge which passes just to
+ * the right of vEvent; we would like to splice vEvent into this edge.
+ *
+ * However, we don't want to connect vEvent to just any vertex. We don''t
+ * want the new edge to cross any other edges; otherwise we will create
+ * intersection vertices even when the input data had no self-intersections.
+ * (This is a bad thing; if the user's input data has no intersections,
+ * we don't want to generate any false intersections ourselves.)
+ *
+ * Our eventual goal is to connect vEvent to the leftmost unprocessed
+ * vertex of the combined region (the union of regUp and regLo).
+ * But because of unseen vertices with all right-going edges, and also
+ * new vertices which may be created by edge intersections, we don''t
+ * know where that leftmost unprocessed vertex is. In the meantime, we
+ * connect vEvent to the closest vertex of either chain, and mark the region
+ * as "fixUpperEdge". This flag says to delete and reconnect this edge
+ * to the next processed vertex on the boundary of the combined region.
+ * Quite possibly the vertex we connected to will turn out to be the
+ * closest one, in which case we won''t need to make any changes.
+ */
+{
+ GLUhalfEdge *eNew;
+ GLUhalfEdge *eTopLeft = eBottomLeft->Onext;
+ ActiveRegion *regLo = RegionBelow(regUp);
+ GLUhalfEdge *eUp = regUp->eUp;
+ GLUhalfEdge *eLo = regLo->eUp;
+ int degenerate = FALSE;
+
+ if( eUp->Dst != eLo->Dst ) {
+ (void) CheckForIntersect( tess, regUp );
+ }
+
+ /* Possible new degeneracies: upper or lower edge of regUp may pass
+ * through vEvent, or may coincide with new intersection vertex
+ */
+ if( VertEq( eUp->Org, tess->event )) {
+ if ( !__gl_meshSplice( eTopLeft->Oprev, eUp ) ) longjmp(tess->env,1);
+ regUp = TopLeftRegion( regUp );
+ if (regUp == NULL) longjmp(tess->env,1);
+ eTopLeft = RegionBelow( regUp )->eUp;
+ FinishLeftRegions( tess, RegionBelow(regUp), regLo );
+ degenerate = TRUE;
+ }
+ if( VertEq( eLo->Org, tess->event )) {
+ if ( !__gl_meshSplice( eBottomLeft, eLo->Oprev ) ) longjmp(tess->env,1);
+ eBottomLeft = FinishLeftRegions( tess, regLo, NULL );
+ degenerate = TRUE;
+ }
+ if( degenerate ) {
+ AddRightEdges( tess, regUp, eBottomLeft->Onext, eTopLeft, eTopLeft, TRUE );
+ return;
+ }
+
+ /* Non-degenerate situation -- need to add a temporary, fixable edge.
+ * Connect to the closer of eLo->Org, eUp->Org.
+ */
+ if( VertLeq( eLo->Org, eUp->Org )) {
+ eNew = eLo->Oprev;
+ } else {
+ eNew = eUp;
+ }
+ eNew = __gl_meshConnect( eBottomLeft->Lprev, eNew );
+ if (eNew == NULL) longjmp(tess->env,1);
+
+ /* Prevent cleanup, otherwise eNew might disappear before we've even
+ * had a chance to mark it as a temporary edge.
+ */
+ AddRightEdges( tess, regUp, eNew, eNew->Onext, eNew->Onext, FALSE );
+ eNew->Sym->activeRegion->fixUpperEdge = TRUE;
+ WalkDirtyRegions( tess, regUp );
+}
+
+/* Because vertices at exactly the same location are merged together
+ * before we process the sweep event, some degenerate cases can't occur.
+ * However if someone eventually makes the modifications required to
+ * merge features which are close together, the cases below marked
+ * TOLERANCE_NONZERO will be useful. They were debugged before the
+ * code to merge identical vertices in the main loop was added.
+ */
+#define TOLERANCE_NONZERO FALSE
+
+static void ConnectLeftDegenerate( GLUtesselator *tess,
+ ActiveRegion *regUp, GLUvertex *vEvent )
+/*
+ * The event vertex lies exacty on an already-processed edge or vertex.
+ * Adding the new vertex involves splicing it into the already-processed
+ * part of the mesh.
+ */
+{
+ GLUhalfEdge *e, *eTopLeft, *eTopRight, *eLast;
+ ActiveRegion *reg;
+
+ e = regUp->eUp;
+ if( VertEq( e->Org, vEvent )) {
+ /* e->Org is an unprocessed vertex - just combine them, and wait
+ * for e->Org to be pulled from the queue
+ */
+ assert( TOLERANCE_NONZERO );
+ SpliceMergeVertices( tess, e, vEvent->anEdge );
+ return;
+ }
+
+ if( ! VertEq( e->Dst, vEvent )) {
+ /* General case -- splice vEvent into edge e which passes through it */
+ if (__gl_meshSplitEdge( e->Sym ) == NULL) longjmp(tess->env,1);
+ if( regUp->fixUpperEdge ) {
+ /* This edge was fixable -- delete unused portion of original edge */
+ if ( !__gl_meshDelete( e->Onext ) ) longjmp(tess->env,1);
+ regUp->fixUpperEdge = FALSE;
+ }
+ if ( !__gl_meshSplice( vEvent->anEdge, e ) ) longjmp(tess->env,1);
+ SweepEvent( tess, vEvent ); /* recurse */
+ return;
+ }
+
+ /* vEvent coincides with e->Dst, which has already been processed.
+ * Splice in the additional right-going edges.
+ */
+ assert( TOLERANCE_NONZERO );
+ regUp = TopRightRegion( regUp );
+ reg = RegionBelow( regUp );
+ eTopRight = reg->eUp->Sym;
+ eTopLeft = eLast = eTopRight->Onext;
+ if( reg->fixUpperEdge ) {
+ /* Here e->Dst has only a single fixable edge going right.
+ * We can delete it since now we have some real right-going edges.
+ */
+ assert( eTopLeft != eTopRight ); /* there are some left edges too */
+ DeleteRegion( tess, reg );
+ if ( !__gl_meshDelete( eTopRight ) ) longjmp(tess->env,1);
+ eTopRight = eTopLeft->Oprev;
+ }
+ if ( !__gl_meshSplice( vEvent->anEdge, eTopRight ) ) longjmp(tess->env,1);
+ if( ! EdgeGoesLeft( eTopLeft )) {
+ /* e->Dst had no left-going edges -- indicate this to AddRightEdges() */
+ eTopLeft = NULL;
+ }
+ AddRightEdges( tess, regUp, eTopRight->Onext, eLast, eTopLeft, TRUE );
+}
+
+
+static void ConnectLeftVertex( GLUtesselator *tess, GLUvertex *vEvent )
+/*
+ * Purpose: connect a "left" vertex (one where both edges go right)
+ * to the processed portion of the mesh. Let R be the active region
+ * containing vEvent, and let U and L be the upper and lower edge
+ * chains of R. There are two possibilities:
+ *
+ * - the normal case: split R into two regions, by connecting vEvent to
+ * the rightmost vertex of U or L lying to the left of the sweep line
+ *
+ * - the degenerate case: if vEvent is close enough to U or L, we
+ * merge vEvent into that edge chain. The subcases are:
+ * - merging with the rightmost vertex of U or L
+ * - merging with the active edge of U or L
+ * - merging with an already-processed portion of U or L
+ */
+{
+ ActiveRegion *regUp, *regLo, *reg;
+ GLUhalfEdge *eUp, *eLo, *eNew;
+ ActiveRegion tmp;
+
+ /* assert( vEvent->anEdge->Onext->Onext == vEvent->anEdge ); */
+
+ /* Get a pointer to the active region containing vEvent */
+ tmp.eUp = vEvent->anEdge->Sym;
+ /* __GL_DICTLISTKEY */ /* __gl_dictListSearch */
+ regUp = (ActiveRegion *)dictKey( dictSearch( tess->dict, &tmp ));
+ regLo = RegionBelow( regUp );
+ eUp = regUp->eUp;
+ eLo = regLo->eUp;
+
+ /* Try merging with U or L first */
+ if( EdgeSign( eUp->Dst, vEvent, eUp->Org ) == 0 ) {
+ ConnectLeftDegenerate( tess, regUp, vEvent );
+ return;
+ }
+
+ /* Connect vEvent to rightmost processed vertex of either chain.
+ * e->Dst is the vertex that we will connect to vEvent.
+ */
+ reg = VertLeq( eLo->Dst, eUp->Dst ) ? regUp : regLo;
+
+ if( regUp->inside || reg->fixUpperEdge) {
+ if( reg == regUp ) {
+ eNew = __gl_meshConnect( vEvent->anEdge->Sym, eUp->Lnext );
+ if (eNew == NULL) longjmp(tess->env,1);
+ } else {
+ GLUhalfEdge *tempHalfEdge= __gl_meshConnect( eLo->Dnext, vEvent->anEdge);
+ if (tempHalfEdge == NULL) longjmp(tess->env,1);
+
+ eNew = tempHalfEdge->Sym;
+ }
+ if( reg->fixUpperEdge ) {
+ if ( !FixUpperEdge( reg, eNew ) ) longjmp(tess->env,1);
+ } else {
+ ComputeWinding( tess, AddRegionBelow( tess, regUp, eNew ));
+ }
+ SweepEvent( tess, vEvent );
+ } else {
+ /* The new vertex is in a region which does not belong to the polygon.
+ * We don''t need to connect this vertex to the rest of the mesh.
+ */
+ AddRightEdges( tess, regUp, vEvent->anEdge, vEvent->anEdge, NULL, TRUE );
+ }
+}
+
+
+static void SweepEvent( GLUtesselator *tess, GLUvertex *vEvent )
+/*
+ * Does everything necessary when the sweep line crosses a vertex.
+ * Updates the mesh and the edge dictionary.
+ */
+{
+ ActiveRegion *regUp, *reg;
+ GLUhalfEdge *e, *eTopLeft, *eBottomLeft;
+
+ tess->event = vEvent; /* for access in EdgeLeq() */
+ DebugEvent( tess );
+
+ /* Check if this vertex is the right endpoint of an edge that is
+ * already in the dictionary. In this case we don't need to waste
+ * time searching for the location to insert new edges.
+ */
+ e = vEvent->anEdge;
+ while( e->activeRegion == NULL ) {
+ e = e->Onext;
+ if( e == vEvent->anEdge ) {
+ /* All edges go right -- not incident to any processed edges */
+ ConnectLeftVertex( tess, vEvent );
+ return;
+ }
+ }
+
+ /* Processing consists of two phases: first we "finish" all the
+ * active regions where both the upper and lower edges terminate
+ * at vEvent (ie. vEvent is closing off these regions).
+ * We mark these faces "inside" or "outside" the polygon according
+ * to their winding number, and delete the edges from the dictionary.
+ * This takes care of all the left-going edges from vEvent.
+ */
+ regUp = TopLeftRegion( e->activeRegion );
+ if (regUp == NULL) longjmp(tess->env,1);
+ reg = RegionBelow( regUp );
+ eTopLeft = reg->eUp;
+ eBottomLeft = FinishLeftRegions( tess, reg, NULL );
+
+ /* Next we process all the right-going edges from vEvent. This
+ * involves adding the edges to the dictionary, and creating the
+ * associated "active regions" which record information about the
+ * regions between adjacent dictionary edges.
+ */
+ if( eBottomLeft->Onext == eTopLeft ) {
+ /* No right-going edges -- add a temporary "fixable" edge */
+ ConnectRightVertex( tess, regUp, eBottomLeft );
+ } else {
+ AddRightEdges( tess, regUp, eBottomLeft->Onext, eTopLeft, eTopLeft, TRUE );
+ }
+}
+
+
+/* Make the sentinel coordinates big enough that they will never be
+ * merged with real input features. (Even with the largest possible
+ * input contour and the maximum tolerance of 1.0, no merging will be
+ * done with coordinates larger than 3 * GLU_TESS_MAX_COORD).
+ */
+#define SENTINEL_COORD (4 * GLU_TESS_MAX_COORD)
+
+static void AddSentinel( GLUtesselator *tess, GLdouble t )
+/*
+ * We add two sentinel edges above and below all other edges,
+ * to avoid special cases at the top and bottom.
+ */
+{
+ GLUhalfEdge *e;
+ ActiveRegion *reg = (ActiveRegion *)memAlloc( sizeof( ActiveRegion ));
+ if (reg == NULL) longjmp(tess->env,1);
+
+ e = __gl_meshMakeEdge( tess->mesh );
+ if (e == NULL) longjmp(tess->env,1);
+
+ e->Org->s = SENTINEL_COORD;
+ e->Org->t = t;
+ e->Dst->s = -SENTINEL_COORD;
+ e->Dst->t = t;
+ tess->event = e->Dst; /* initialize it */
+
+ reg->eUp = e;
+ reg->windingNumber = 0;
+ reg->inside = FALSE;
+ reg->fixUpperEdge = FALSE;
+ reg->sentinel = TRUE;
+ reg->dirty = FALSE;
+ reg->nodeUp = dictInsert( tess->dict, reg ); /* __gl_dictListInsertBefore */
+ if (reg->nodeUp == NULL) longjmp(tess->env,1);
+}
+
+
+static void InitEdgeDict( GLUtesselator *tess )
+/*
+ * We maintain an ordering of edge intersections with the sweep line.
+ * This order is maintained in a dynamic dictionary.
+ */
+{
+ /* __gl_dictListNewDict */
+ tess->dict = dictNewDict( tess, (int (*)(void *, DictKey, DictKey)) EdgeLeq );
+ if (tess->dict == NULL) longjmp(tess->env,1);
+
+ AddSentinel( tess, -SENTINEL_COORD );
+ AddSentinel( tess, SENTINEL_COORD );
+}
+
+
+static void DoneEdgeDict( GLUtesselator *tess )
+{
+ ActiveRegion *reg;
+#ifndef NDEBUG
+ int fixedEdges = 0;
+#endif
+
+ /* __GL_DICTLISTKEY */ /* __GL_DICTLISTMIN */
+ while( (reg = (ActiveRegion *)dictKey( dictMin( tess->dict ))) != NULL ) {
+ /*
+ * At the end of all processing, the dictionary should contain
+ * only the two sentinel edges, plus at most one "fixable" edge
+ * created by ConnectRightVertex().
+ */
+ if( ! reg->sentinel ) {
+ assert( reg->fixUpperEdge );
+ assert( ++fixedEdges == 1 );
+ }
+ assert( reg->windingNumber == 0 );
+ DeleteRegion( tess, reg );
+/* __gl_meshDelete( reg->eUp );*/
+ }
+ dictDeleteDict( tess->dict ); /* __gl_dictListDeleteDict */
+}
+
+
+static void RemoveDegenerateEdges( GLUtesselator *tess )
+/*
+ * Remove zero-length edges, and contours with fewer than 3 vertices.
+ */
+{
+ GLUhalfEdge *e, *eNext, *eLnext;
+ GLUhalfEdge *eHead = &tess->mesh->eHead;
+
+ /*LINTED*/
+ for( e = eHead->next; e != eHead; e = eNext ) {
+ eNext = e->next;
+ eLnext = e->Lnext;
+
+ if( VertEq( e->Org, e->Dst ) && e->Lnext->Lnext != e ) {
+ /* Zero-length edge, contour has at least 3 edges */
+
+ SpliceMergeVertices( tess, eLnext, e ); /* deletes e->Org */
+ if ( !__gl_meshDelete( e ) ) longjmp(tess->env,1); /* e is a self-loop */
+ e = eLnext;
+ eLnext = e->Lnext;
+ }
+ if( eLnext->Lnext == e ) {
+ /* Degenerate contour (one or two edges) */
+
+ if( eLnext != e ) {
+ if( eLnext == eNext || eLnext == eNext->Sym ) { eNext = eNext->next; }
+ if ( !__gl_meshDelete( eLnext ) ) longjmp(tess->env,1);
+ }
+ if( e == eNext || e == eNext->Sym ) { eNext = eNext->next; }
+ if ( !__gl_meshDelete( e ) ) longjmp(tess->env,1);
+ }
+ }
+}
+
+static int InitPriorityQ( GLUtesselator *tess )
+/*
+ * Insert all vertices into the priority queue which determines the
+ * order in which vertices cross the sweep line.
+ */
+{
+ PriorityQ *pq;
+ GLUvertex *v, *vHead;
+
+ /* __gl_pqSortNewPriorityQ */
+ pq = tess->pq = pqNewPriorityQ( (int (*)(PQkey, PQkey)) __gl_vertLeq );
+ if (pq == NULL) return 0;
+
+ vHead = &tess->mesh->vHead;
+ for( v = vHead->next; v != vHead; v = v->next ) {
+ v->pqHandle = pqInsert( pq, v ); /* __gl_pqSortInsert */
+ if (v->pqHandle == LONG_MAX) break;
+ }
+ if (v != vHead || !pqInit( pq ) ) { /* __gl_pqSortInit */
+ pqDeletePriorityQ(tess->pq); /* __gl_pqSortDeletePriorityQ */
+ tess->pq = NULL;
+ return 0;
+ }
+
+ return 1;
+}
+
+
+static void DonePriorityQ( GLUtesselator *tess )
+{
+ pqDeletePriorityQ( tess->pq ); /* __gl_pqSortDeletePriorityQ */
+}
+
+
+static int RemoveDegenerateFaces( GLUmesh *mesh )
+/*
+ * Delete any degenerate faces with only two edges. WalkDirtyRegions()
+ * will catch almost all of these, but it won't catch degenerate faces
+ * produced by splice operations on already-processed edges.
+ * The two places this can happen are in FinishLeftRegions(), when
+ * we splice in a "temporary" edge produced by ConnectRightVertex(),
+ * and in CheckForLeftSplice(), where we splice already-processed
+ * edges to ensure that our dictionary invariants are not violated
+ * by numerical errors.
+ *
+ * In both these cases it is *very* dangerous to delete the offending
+ * edge at the time, since one of the routines further up the stack
+ * will sometimes be keeping a pointer to that edge.
+ */
+{
+ GLUface *f, *fNext;
+ GLUhalfEdge *e;
+
+ /*LINTED*/
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) {
+ fNext = f->next;
+ e = f->anEdge;
+ assert( e->Lnext != e );
+
+ if( e->Lnext->Lnext == e ) {
+ /* A face with only two edges */
+ AddWinding( e->Onext, e );
+ if ( !__gl_meshDelete( e ) ) return 0;
+ }
+ }
+ return 1;
+}
+
+int __gl_computeInterior( GLUtesselator *tess )
+/*
+ * __gl_computeInterior( tess ) computes the planar arrangement specified
+ * by the given contours, and further subdivides this arrangement
+ * into regions. Each region is marked "inside" if it belongs
+ * to the polygon, according to the rule given by tess->windingRule.
+ * Each interior region is guaranteed be monotone.
+ */
+{
+ GLUvertex *v, *vNext;
+
+ tess->fatalError = FALSE;
+
+ /* Each vertex defines an event for our sweep line. Start by inserting
+ * all the vertices in a priority queue. Events are processed in
+ * lexicographic order, ie.
+ *
+ * e1 < e2 iff e1.x < e2.x || (e1.x == e2.x && e1.y < e2.y)
+ */
+ RemoveDegenerateEdges( tess );
+ if ( !InitPriorityQ( tess ) ) return 0; /* if error */
+ InitEdgeDict( tess );
+
+ /* __gl_pqSortExtractMin */
+ while( (v = (GLUvertex *)pqExtractMin( tess->pq )) != NULL ) {
+ for( ;; ) {
+ vNext = (GLUvertex *)pqMinimum( tess->pq ); /* __gl_pqSortMinimum */
+ if( vNext == NULL || ! VertEq( vNext, v )) break;
+
+ /* Merge together all vertices at exactly the same location.
+ * This is more efficient than processing them one at a time,
+ * simplifies the code (see ConnectLeftDegenerate), and is also
+ * important for correct handling of certain degenerate cases.
+ * For example, suppose there are two identical edges A and B
+ * that belong to different contours (so without this code they would
+ * be processed by separate sweep events). Suppose another edge C
+ * crosses A and B from above. When A is processed, we split it
+ * at its intersection point with C. However this also splits C,
+ * so when we insert B we may compute a slightly different
+ * intersection point. This might leave two edges with a small
+ * gap between them. This kind of error is especially obvious
+ * when using boundary extraction (GLU_TESS_BOUNDARY_ONLY).
+ */
+ vNext = (GLUvertex *)pqExtractMin( tess->pq ); /* __gl_pqSortExtractMin*/
+ SpliceMergeVertices( tess, v->anEdge, vNext->anEdge );
+ }
+ SweepEvent( tess, v );
+ }
+
+ /* Set tess->event for debugging purposes */
+ /* __GL_DICTLISTKEY */ /* __GL_DICTLISTMIN */
+ tess->event = ((ActiveRegion *) dictKey( dictMin( tess->dict )))->eUp->Org;
+ DebugEvent( tess );
+ DoneEdgeDict( tess );
+ DonePriorityQ( tess );
+
+ if ( !RemoveDegenerateFaces( tess->mesh ) ) return 0;
+ __gl_meshCheckMesh( tess->mesh );
+
+ return 1;
+}
diff --git a/cogl/tesselator/sweep.h b/cogl/tesselator/sweep.h
new file mode 100644
index 000000000..feb68b0ff
--- /dev/null
+++ b/cogl/tesselator/sweep.h
@@ -0,0 +1,77 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __sweep_h_
+#define __sweep_h_
+
+#include "mesh.h"
+
+/* __gl_computeInterior( tess ) computes the planar arrangement specified
+ * by the given contours, and further subdivides this arrangement
+ * into regions. Each region is marked "inside" if it belongs
+ * to the polygon, according to the rule given by tess->windingRule.
+ * Each interior region is guaranteed be monotone.
+ */
+int __gl_computeInterior( GLUtesselator *tess );
+
+
+/* The following is here *only* for access by debugging routines */
+
+#include "dict.h"
+
+/* For each pair of adjacent edges crossing the sweep line, there is
+ * an ActiveRegion to represent the region between them. The active
+ * regions are kept in sorted order in a dynamic dictionary. As the
+ * sweep line crosses each vertex, we update the affected regions.
+ */
+
+struct ActiveRegion {
+ GLUhalfEdge *eUp; /* upper edge, directed right to left */
+ DictNode *nodeUp; /* dictionary node corresponding to eUp */
+ int windingNumber; /* used to determine which regions are
+ * inside the polygon */
+ GLboolean inside; /* is this region inside the polygon? */
+ GLboolean sentinel; /* marks fake edges at t = +/-infinity */
+ GLboolean dirty; /* marks regions where the upper or lower
+ * edge has changed, but we haven't checked
+ * whether they intersect yet */
+ GLboolean fixUpperEdge; /* marks temporary edges introduced when
+ * we process a "right vertex" (one without
+ * any edges leaving to the right) */
+};
+
+#define RegionBelow(r) ((ActiveRegion *) dictKey(dictPred((r)->nodeUp)))
+#define RegionAbove(r) ((ActiveRegion *) dictKey(dictSucc((r)->nodeUp)))
+
+#endif
diff --git a/cogl/tesselator/tess.c b/cogl/tesselator/tess.c
new file mode 100644
index 000000000..029a02c3a
--- /dev/null
+++ b/cogl/tesselator/tess.c
@@ -0,0 +1,628 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include
+#include
+#include "memalloc.h"
+#include "tess.h"
+#include "mesh.h"
+#include "normal.h"
+#include "sweep.h"
+#include "tessmono.h"
+#include "render.h"
+
+#define GLU_TESS_DEFAULT_TOLERANCE 0.0
+#define GLU_TESS_MESH 100112 /* void (*)(GLUmesh *mesh) */
+
+#define TRUE 1
+#define FALSE 0
+
+/*ARGSUSED*/ static void GLAPIENTRY noBegin( GLenum type ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noEdgeFlag( GLboolean boundaryEdge ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noVertex( void *data ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noEnd( void ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noError( GLenum errnum ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noCombine( GLdouble coords[3], void *data[4],
+ GLfloat weight[4], void **dataOut ) {}
+/*ARGSUSED*/ static void GLAPIENTRY noMesh( GLUmesh *mesh ) {}
+
+
+/*ARGSUSED*/ void GLAPIENTRY __gl_noBeginData( GLenum type,
+ void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge,
+ void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noVertexData( void *data,
+ void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noEndData( void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noErrorData( GLenum errnum,
+ void *polygonData ) {}
+/*ARGSUSED*/ void GLAPIENTRY __gl_noCombineData( GLdouble coords[3],
+ void *data[4],
+ GLfloat weight[4],
+ void **outData,
+ void *polygonData ) {}
+
+/* Half-edges are allocated in pairs (see mesh.c) */
+typedef struct { GLUhalfEdge e, eSym; } EdgePair;
+
+#undef MAX
+#define MAX(a,b) ((a) > (b) ? (a) : (b))
+#define MAX_FAST_ALLOC (MAX(sizeof(EdgePair), \
+ MAX(sizeof(GLUvertex),sizeof(GLUface))))
+
+
+GLUtesselator * GLAPIENTRY
+gluNewTess( void )
+{
+ GLUtesselator *tess;
+
+ /* Only initialize fields which can be changed by the api. Other fields
+ * are initialized where they are used.
+ */
+
+ if (memInit( MAX_FAST_ALLOC ) == 0) {
+ return 0; /* out of memory */
+ }
+ tess = (GLUtesselator *)memAlloc( sizeof( GLUtesselator ));
+ if (tess == NULL) {
+ return 0; /* out of memory */
+ }
+
+ tess->state = T_DORMANT;
+
+ tess->normal[0] = 0;
+ tess->normal[1] = 0;
+ tess->normal[2] = 0;
+
+ tess->relTolerance = GLU_TESS_DEFAULT_TOLERANCE;
+ tess->windingRule = GLU_TESS_WINDING_ODD;
+ tess->flagBoundary = FALSE;
+ tess->boundaryOnly = FALSE;
+
+ tess->callBegin = &noBegin;
+ tess->callEdgeFlag = &noEdgeFlag;
+ tess->callVertex = &noVertex;
+ tess->callEnd = &noEnd;
+
+ tess->callError = &noError;
+ tess->callCombine = &noCombine;
+ tess->callMesh = &noMesh;
+
+ tess->callBeginData= &__gl_noBeginData;
+ tess->callEdgeFlagData= &__gl_noEdgeFlagData;
+ tess->callVertexData= &__gl_noVertexData;
+ tess->callEndData= &__gl_noEndData;
+ tess->callErrorData= &__gl_noErrorData;
+ tess->callCombineData= &__gl_noCombineData;
+
+ tess->polygonData= NULL;
+
+ return tess;
+}
+
+static void MakeDormant( GLUtesselator *tess )
+{
+ /* Return the tessellator to its original dormant state. */
+
+ if( tess->mesh != NULL ) {
+ __gl_meshDeleteMesh( tess->mesh );
+ }
+ tess->state = T_DORMANT;
+ tess->lastEdge = NULL;
+ tess->mesh = NULL;
+}
+
+#define RequireState( tess, s ) if( tess->state != s ) GotoState(tess,s)
+
+static void GotoState( GLUtesselator *tess, enum TessState newState )
+{
+ while( tess->state != newState ) {
+ /* We change the current state one level at a time, to get to
+ * the desired state.
+ */
+ if( tess->state < newState ) {
+ switch( tess->state ) {
+ case T_DORMANT:
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_POLYGON );
+ gluTessBeginPolygon( tess, NULL );
+ break;
+ case T_IN_POLYGON:
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_BEGIN_CONTOUR );
+ gluTessBeginContour( tess );
+ break;
+ default:
+ ;
+ }
+ } else {
+ switch( tess->state ) {
+ case T_IN_CONTOUR:
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_CONTOUR );
+ gluTessEndContour( tess );
+ break;
+ case T_IN_POLYGON:
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_MISSING_END_POLYGON );
+ /* gluTessEndPolygon( tess ) is too much work! */
+ MakeDormant( tess );
+ break;
+ default:
+ ;
+ }
+ }
+ }
+}
+
+
+void GLAPIENTRY
+gluDeleteTess( GLUtesselator *tess )
+{
+ RequireState( tess, T_DORMANT );
+ memFree( tess );
+}
+
+
+void GLAPIENTRY
+gluTessProperty( GLUtesselator *tess, GLenum which, GLdouble value )
+{
+ GLenum windingRule;
+
+ switch( which ) {
+ case GLU_TESS_TOLERANCE:
+ if( value < 0.0 || value > 1.0 ) break;
+ tess->relTolerance = value;
+ return;
+
+ case GLU_TESS_WINDING_RULE:
+ windingRule = (GLenum) value;
+ if( windingRule != value ) break; /* not an integer */
+
+ switch( windingRule ) {
+ case GLU_TESS_WINDING_ODD:
+ case GLU_TESS_WINDING_NONZERO:
+ case GLU_TESS_WINDING_POSITIVE:
+ case GLU_TESS_WINDING_NEGATIVE:
+ case GLU_TESS_WINDING_ABS_GEQ_TWO:
+ tess->windingRule = windingRule;
+ return;
+ default:
+ break;
+ }
+
+ case GLU_TESS_BOUNDARY_ONLY:
+ tess->boundaryOnly = (value != 0);
+ return;
+
+ default:
+ CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+ return;
+ }
+ CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_VALUE );
+}
+
+/* Returns tessellator property */
+void GLAPIENTRY
+gluGetTessProperty( GLUtesselator *tess, GLenum which, GLdouble *value )
+{
+ switch (which) {
+ case GLU_TESS_TOLERANCE:
+ /* tolerance should be in range [0..1] */
+ assert(0.0 <= tess->relTolerance && tess->relTolerance <= 1.0);
+ *value= tess->relTolerance;
+ break;
+ case GLU_TESS_WINDING_RULE:
+ assert(tess->windingRule == GLU_TESS_WINDING_ODD ||
+ tess->windingRule == GLU_TESS_WINDING_NONZERO ||
+ tess->windingRule == GLU_TESS_WINDING_POSITIVE ||
+ tess->windingRule == GLU_TESS_WINDING_NEGATIVE ||
+ tess->windingRule == GLU_TESS_WINDING_ABS_GEQ_TWO);
+ *value= tess->windingRule;
+ break;
+ case GLU_TESS_BOUNDARY_ONLY:
+ assert(tess->boundaryOnly == TRUE || tess->boundaryOnly == FALSE);
+ *value= tess->boundaryOnly;
+ break;
+ default:
+ *value= 0.0;
+ CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+ break;
+ }
+} /* gluGetTessProperty() */
+
+void GLAPIENTRY
+gluTessNormal( GLUtesselator *tess, GLdouble x, GLdouble y, GLdouble z )
+{
+ tess->normal[0] = x;
+ tess->normal[1] = y;
+ tess->normal[2] = z;
+}
+
+void GLAPIENTRY
+gluTessCallback( GLUtesselator *tess, GLenum which, _GLUfuncptr fn)
+{
+ switch( which ) {
+ case GLU_TESS_BEGIN:
+ tess->callBegin = (fn == NULL) ? &noBegin : (void (GLAPIENTRY *)(GLenum)) fn;
+ return;
+ case GLU_TESS_BEGIN_DATA:
+ tess->callBeginData = (fn == NULL) ?
+ &__gl_noBeginData : (void (GLAPIENTRY *)(GLenum, void *)) fn;
+ return;
+ case GLU_TESS_EDGE_FLAG:
+ tess->callEdgeFlag = (fn == NULL) ? &noEdgeFlag :
+ (void (GLAPIENTRY *)(GLboolean)) fn;
+ /* If the client wants boundary edges to be flagged,
+ * we render everything as separate triangles (no strips or fans).
+ */
+ tess->flagBoundary = (fn != NULL);
+ return;
+ case GLU_TESS_EDGE_FLAG_DATA:
+ tess->callEdgeFlagData= (fn == NULL) ?
+ &__gl_noEdgeFlagData : (void (GLAPIENTRY *)(GLboolean, void *)) fn;
+ /* If the client wants boundary edges to be flagged,
+ * we render everything as separate triangles (no strips or fans).
+ */
+ tess->flagBoundary = (fn != NULL);
+ return;
+ case GLU_TESS_VERTEX:
+ tess->callVertex = (fn == NULL) ? &noVertex :
+ (void (GLAPIENTRY *)(void *)) fn;
+ return;
+ case GLU_TESS_VERTEX_DATA:
+ tess->callVertexData = (fn == NULL) ?
+ &__gl_noVertexData : (void (GLAPIENTRY *)(void *, void *)) fn;
+ return;
+ case GLU_TESS_END:
+ tess->callEnd = (fn == NULL) ? &noEnd : (void (GLAPIENTRY *)(void)) fn;
+ return;
+ case GLU_TESS_END_DATA:
+ tess->callEndData = (fn == NULL) ? &__gl_noEndData :
+ (void (GLAPIENTRY *)(void *)) fn;
+ return;
+ case GLU_TESS_ERROR:
+ tess->callError = (fn == NULL) ? &noError : (void (GLAPIENTRY *)(GLenum)) fn;
+ return;
+ case GLU_TESS_ERROR_DATA:
+ tess->callErrorData = (fn == NULL) ?
+ &__gl_noErrorData : (void (GLAPIENTRY *)(GLenum, void *)) fn;
+ return;
+ case GLU_TESS_COMBINE:
+ tess->callCombine = (fn == NULL) ? &noCombine :
+ (void (GLAPIENTRY *)(GLdouble [3],void *[4], GLfloat [4], void ** )) fn;
+ return;
+ case GLU_TESS_COMBINE_DATA:
+ tess->callCombineData = (fn == NULL) ? &__gl_noCombineData :
+ (void (GLAPIENTRY *)(GLdouble [3],
+ void *[4],
+ GLfloat [4],
+ void **,
+ void *)) fn;
+ return;
+ case GLU_TESS_MESH:
+ tess->callMesh = (fn == NULL) ? &noMesh : (void (GLAPIENTRY *)(GLUmesh *)) fn;
+ return;
+ default:
+ CALL_ERROR_OR_ERROR_DATA( GLU_INVALID_ENUM );
+ return;
+ }
+}
+
+static int AddVertex( GLUtesselator *tess, GLdouble coords[3], void *data )
+{
+ GLUhalfEdge *e;
+
+ e = tess->lastEdge;
+ if( e == NULL ) {
+ /* Make a self-loop (one vertex, one edge). */
+
+ e = __gl_meshMakeEdge( tess->mesh );
+ if (e == NULL) return 0;
+ if ( !__gl_meshSplice( e, e->Sym ) ) return 0;
+ } else {
+ /* Create a new vertex and edge which immediately follow e
+ * in the ordering around the left face.
+ */
+ if (__gl_meshSplitEdge( e ) == NULL) return 0;
+ e = e->Lnext;
+ }
+
+ /* The new vertex is now e->Org. */
+ e->Org->data = data;
+ e->Org->coords[0] = coords[0];
+ e->Org->coords[1] = coords[1];
+ e->Org->coords[2] = coords[2];
+
+ /* The winding of an edge says how the winding number changes as we
+ * cross from the edge''s right face to its left face. We add the
+ * vertices in such an order that a CCW contour will add +1 to
+ * the winding number of the region inside the contour.
+ */
+ e->winding = 1;
+ e->Sym->winding = -1;
+
+ tess->lastEdge = e;
+
+ return 1;
+}
+
+
+static void CacheVertex( GLUtesselator *tess, GLdouble coords[3], void *data )
+{
+ CachedVertex *v = &tess->cache[tess->cacheCount];
+
+ v->data = data;
+ v->coords[0] = coords[0];
+ v->coords[1] = coords[1];
+ v->coords[2] = coords[2];
+ ++tess->cacheCount;
+}
+
+
+static int EmptyCache( GLUtesselator *tess )
+{
+ CachedVertex *v = tess->cache;
+ CachedVertex *vLast;
+
+ tess->mesh = __gl_meshNewMesh();
+ if (tess->mesh == NULL) return 0;
+
+ for( vLast = v + tess->cacheCount; v < vLast; ++v ) {
+ if ( !AddVertex( tess, v->coords, v->data ) ) return 0;
+ }
+ tess->cacheCount = 0;
+ tess->emptyCache = FALSE;
+
+ return 1;
+}
+
+
+void GLAPIENTRY
+gluTessVertex( GLUtesselator *tess, GLdouble coords[3], void *data )
+{
+ int i, tooLarge = FALSE;
+ GLdouble x, clamped[3];
+
+ RequireState( tess, T_IN_CONTOUR );
+
+ if( tess->emptyCache ) {
+ if ( !EmptyCache( tess ) ) {
+ CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+ return;
+ }
+ tess->lastEdge = NULL;
+ }
+ for( i = 0; i < 3; ++i ) {
+ x = coords[i];
+ if( x < - GLU_TESS_MAX_COORD ) {
+ x = - GLU_TESS_MAX_COORD;
+ tooLarge = TRUE;
+ }
+ if( x > GLU_TESS_MAX_COORD ) {
+ x = GLU_TESS_MAX_COORD;
+ tooLarge = TRUE;
+ }
+ clamped[i] = x;
+ }
+ if( tooLarge ) {
+ CALL_ERROR_OR_ERROR_DATA( GLU_TESS_COORD_TOO_LARGE );
+ }
+
+ if( tess->mesh == NULL ) {
+ if( tess->cacheCount < TESS_MAX_CACHE ) {
+ CacheVertex( tess, clamped, data );
+ return;
+ }
+ if ( !EmptyCache( tess ) ) {
+ CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+ return;
+ }
+ }
+ if ( !AddVertex( tess, clamped, data ) ) {
+ CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+ }
+}
+
+
+void GLAPIENTRY
+gluTessBeginPolygon( GLUtesselator *tess, void *data )
+{
+ RequireState( tess, T_DORMANT );
+
+ tess->state = T_IN_POLYGON;
+ tess->cacheCount = 0;
+ tess->emptyCache = FALSE;
+ tess->mesh = NULL;
+
+ tess->polygonData= data;
+}
+
+
+void GLAPIENTRY
+gluTessBeginContour( GLUtesselator *tess )
+{
+ RequireState( tess, T_IN_POLYGON );
+
+ tess->state = T_IN_CONTOUR;
+ tess->lastEdge = NULL;
+ if( tess->cacheCount > 0 ) {
+ /* Just set a flag so we don't get confused by empty contours
+ * -- these can be generated accidentally with the obsolete
+ * NextContour() interface.
+ */
+ tess->emptyCache = TRUE;
+ }
+}
+
+
+void GLAPIENTRY
+gluTessEndContour( GLUtesselator *tess )
+{
+ RequireState( tess, T_IN_CONTOUR );
+ tess->state = T_IN_POLYGON;
+}
+
+void GLAPIENTRY
+gluTessEndPolygon( GLUtesselator *tess )
+{
+ GLUmesh *mesh;
+
+ if (setjmp(tess->env) != 0) {
+ /* come back here if out of memory */
+ CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
+ return;
+ }
+
+ RequireState( tess, T_IN_POLYGON );
+ tess->state = T_DORMANT;
+
+ if( tess->mesh == NULL ) {
+ if( ! tess->flagBoundary && tess->callMesh == &noMesh ) {
+
+ /* Try some special code to make the easy cases go quickly
+ * (eg. convex polygons). This code does NOT handle multiple contours,
+ * intersections, edge flags, and of course it does not generate
+ * an explicit mesh either.
+ */
+ if( __gl_renderCache( tess )) {
+ tess->polygonData= NULL;
+ return;
+ }
+ }
+ if ( !EmptyCache( tess ) ) longjmp(tess->env,1); /* could've used a label*/
+ }
+
+ /* Determine the polygon normal and project vertices onto the plane
+ * of the polygon.
+ */
+ __gl_projectPolygon( tess );
+
+ /* __gl_computeInterior( tess ) computes the planar arrangement specified
+ * by the given contours, and further subdivides this arrangement
+ * into regions. Each region is marked "inside" if it belongs
+ * to the polygon, according to the rule given by tess->windingRule.
+ * Each interior region is guaranteed be monotone.
+ */
+ if ( !__gl_computeInterior( tess ) ) {
+ longjmp(tess->env,1); /* could've used a label */
+ }
+
+ mesh = tess->mesh;
+ if( ! tess->fatalError ) {
+ int rc = 1;
+
+ /* If the user wants only the boundary contours, we throw away all edges
+ * except those which separate the interior from the exterior.
+ * Otherwise we tessellate all the regions marked "inside".
+ */
+ if( tess->boundaryOnly ) {
+ rc = __gl_meshSetWindingNumber( mesh, 1, TRUE );
+ } else {
+ rc = __gl_meshTessellateInterior( mesh );
+ }
+ if (rc == 0) longjmp(tess->env,1); /* could've used a label */
+
+ __gl_meshCheckMesh( mesh );
+
+ if( tess->callBegin != &noBegin || tess->callEnd != &noEnd
+ || tess->callVertex != &noVertex || tess->callEdgeFlag != &noEdgeFlag
+ || tess->callBeginData != &__gl_noBeginData
+ || tess->callEndData != &__gl_noEndData
+ || tess->callVertexData != &__gl_noVertexData
+ || tess->callEdgeFlagData != &__gl_noEdgeFlagData )
+ {
+ if( tess->boundaryOnly ) {
+ __gl_renderBoundary( tess, mesh ); /* output boundary contours */
+ } else {
+ __gl_renderMesh( tess, mesh ); /* output strips and fans */
+ }
+ }
+ if( tess->callMesh != &noMesh ) {
+
+ /* Throw away the exterior faces, so that all faces are interior.
+ * This way the user doesn't have to check the "inside" flag,
+ * and we don't need to even reveal its existence. It also leaves
+ * the freedom for an implementation to not generate the exterior
+ * faces in the first place.
+ */
+ __gl_meshDiscardExterior( mesh );
+ (*tess->callMesh)( mesh ); /* user wants the mesh itself */
+ tess->mesh = NULL;
+ tess->polygonData= NULL;
+ return;
+ }
+ }
+ __gl_meshDeleteMesh( mesh );
+ tess->polygonData= NULL;
+ tess->mesh = NULL;
+}
+
+
+/*XXXblythe unused function*/
+#if 0
+void GLAPIENTRY
+gluDeleteMesh( GLUmesh *mesh )
+{
+ __gl_meshDeleteMesh( mesh );
+}
+#endif
+
+
+
+/*******************************************************/
+
+/* Obsolete calls -- for backward compatibility */
+
+void GLAPIENTRY
+gluBeginPolygon( GLUtesselator *tess )
+{
+ gluTessBeginPolygon( tess, NULL );
+ gluTessBeginContour( tess );
+}
+
+
+/*ARGSUSED*/
+void GLAPIENTRY
+gluNextContour( GLUtesselator *tess, GLenum type )
+{
+ gluTessEndContour( tess );
+ gluTessBeginContour( tess );
+}
+
+
+void GLAPIENTRY
+gluEndPolygon( GLUtesselator *tess )
+{
+ gluTessEndContour( tess );
+ gluTessEndPolygon( tess );
+}
diff --git a/cogl/tesselator/tess.h b/cogl/tesselator/tess.h
new file mode 100644
index 000000000..162496088
--- /dev/null
+++ b/cogl/tesselator/tess.h
@@ -0,0 +1,165 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __tess_h_
+#define __tess_h_
+
+#include
+#include
+#include "mesh.h"
+#include "dict.h"
+#include "priorityq.h"
+
+/* The begin/end calls must be properly nested. We keep track of
+ * the current state to enforce the ordering.
+ */
+enum TessState { T_DORMANT, T_IN_POLYGON, T_IN_CONTOUR };
+
+/* We cache vertex data for single-contour polygons so that we can
+ * try a quick-and-dirty decomposition first.
+ */
+#define TESS_MAX_CACHE 100
+
+typedef struct CachedVertex {
+ GLdouble coords[3];
+ void *data;
+} CachedVertex;
+
+struct GLUtesselator {
+
+ /*** state needed for collecting the input data ***/
+
+ enum TessState state; /* what begin/end calls have we seen? */
+
+ GLUhalfEdge *lastEdge; /* lastEdge->Org is the most recent vertex */
+ GLUmesh *mesh; /* stores the input contours, and eventually
+ the tessellation itself */
+
+ void (GLAPIENTRY *callError)( GLenum errnum );
+
+ /*** state needed for projecting onto the sweep plane ***/
+
+ GLdouble normal[3]; /* user-specified normal (if provided) */
+ GLdouble sUnit[3]; /* unit vector in s-direction (debugging) */
+ GLdouble tUnit[3]; /* unit vector in t-direction (debugging) */
+
+ /*** state needed for the line sweep ***/
+
+ GLdouble relTolerance; /* tolerance for merging features */
+ GLenum windingRule; /* rule for determining polygon interior */
+ GLboolean fatalError; /* fatal error: needed combine callback */
+
+ Dict *dict; /* edge dictionary for sweep line */
+ PriorityQ *pq; /* priority queue of vertex events */
+ GLUvertex *event; /* current sweep event being processed */
+
+ void (GLAPIENTRY *callCombine)( GLdouble coords[3], void *data[4],
+ GLfloat weight[4], void **outData );
+
+ /*** state needed for rendering callbacks (see render.c) ***/
+
+ GLboolean flagBoundary; /* mark boundary edges (use EdgeFlag) */
+ GLboolean boundaryOnly; /* Extract contours, not triangles */
+ GLUface *lonelyTriList;
+ /* list of triangles which could not be rendered as strips or fans */
+
+ void (GLAPIENTRY *callBegin)( GLenum type );
+ void (GLAPIENTRY *callEdgeFlag)( GLboolean boundaryEdge );
+ void (GLAPIENTRY *callVertex)( void *data );
+ void (GLAPIENTRY *callEnd)( void );
+ void (GLAPIENTRY *callMesh)( GLUmesh *mesh );
+
+
+ /*** state needed to cache single-contour polygons for renderCache() */
+
+ GLboolean emptyCache; /* empty cache on next vertex() call */
+ int cacheCount; /* number of cached vertices */
+ CachedVertex cache[TESS_MAX_CACHE]; /* the vertex data */
+
+ /*** rendering callbacks that also pass polygon data ***/
+ void (GLAPIENTRY *callBeginData)( GLenum type, void *polygonData );
+ void (GLAPIENTRY *callEdgeFlagData)( GLboolean boundaryEdge,
+ void *polygonData );
+ void (GLAPIENTRY *callVertexData)( void *data, void *polygonData );
+ void (GLAPIENTRY *callEndData)( void *polygonData );
+ void (GLAPIENTRY *callErrorData)( GLenum errnum, void *polygonData );
+ void (GLAPIENTRY *callCombineData)( GLdouble coords[3], void *data[4],
+ GLfloat weight[4], void **outData,
+ void *polygonData );
+
+ jmp_buf env; /* place to jump to when memAllocs fail */
+
+ void *polygonData; /* client data for current polygon */
+};
+
+void GLAPIENTRY __gl_noBeginData( GLenum type, void *polygonData );
+void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge, void *polygonData );
+void GLAPIENTRY __gl_noVertexData( void *data, void *polygonData );
+void GLAPIENTRY __gl_noEndData( void *polygonData );
+void GLAPIENTRY __gl_noErrorData( GLenum errnum, void *polygonData );
+void GLAPIENTRY __gl_noCombineData( GLdouble coords[3], void *data[4],
+ GLfloat weight[4], void **outData,
+ void *polygonData );
+
+#define CALL_BEGIN_OR_BEGIN_DATA(a) \
+ if (tess->callBeginData != &__gl_noBeginData) \
+ (*tess->callBeginData)((a),tess->polygonData); \
+ else (*tess->callBegin)((a));
+
+#define CALL_VERTEX_OR_VERTEX_DATA(a) \
+ if (tess->callVertexData != &__gl_noVertexData) \
+ (*tess->callVertexData)((a),tess->polygonData); \
+ else (*tess->callVertex)((a));
+
+#define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
+ if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
+ (*tess->callEdgeFlagData)((a),tess->polygonData); \
+ else (*tess->callEdgeFlag)((a));
+
+#define CALL_END_OR_END_DATA() \
+ if (tess->callEndData != &__gl_noEndData) \
+ (*tess->callEndData)(tess->polygonData); \
+ else (*tess->callEnd)();
+
+#define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
+ if (tess->callCombineData != &__gl_noCombineData) \
+ (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
+ else (*tess->callCombine)((a),(b),(c),(d));
+
+#define CALL_ERROR_OR_ERROR_DATA(a) \
+ if (tess->callErrorData != &__gl_noErrorData) \
+ (*tess->callErrorData)((a),tess->polygonData); \
+ else (*tess->callError)((a));
+
+#endif
diff --git a/cogl/tesselator/tesselator.h b/cogl/tesselator/tesselator.h
new file mode 100644
index 000000000..48fb25e45
--- /dev/null
+++ b/cogl/tesselator/tesselator.h
@@ -0,0 +1,121 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ * Copyright (C) 2010 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+
+#ifndef __TESSELATOR_H__
+#define __TESSELATOR_H__
+
+/* This just includes the defines needed by the tesselator code */
+
+#include "cogl/cogl-defines.h"
+
+typedef struct GLUtesselator GLUtesselator;
+
+#define GLU_TESS_MAX_COORD 1.0e150
+
+GLAPI void GLAPIENTRY gluBeginPolygon (GLUtesselator* tess);
+GLAPI void GLAPIENTRY gluDeleteTess (GLUtesselator* tess);
+GLAPI void GLAPIENTRY gluEndPolygon (GLUtesselator* tess);
+
+typedef void (GLAPIENTRYP _GLUfuncptr)();
+
+GLAPI void GLAPIENTRY gluGetTessProperty (GLUtesselator* tess, GLenum which, GLdouble* data);
+
+GLAPI GLUtesselator* GLAPIENTRY gluNewTess (void);
+GLAPI void GLAPIENTRY gluNextContour (GLUtesselator* tess, GLenum type);
+
+GLAPI void GLAPIENTRY gluTessBeginContour (GLUtesselator* tess);
+GLAPI void GLAPIENTRY gluTessBeginPolygon (GLUtesselator* tess, GLvoid* data);
+GLAPI void GLAPIENTRY gluTessCallback (GLUtesselator* tess, GLenum which, _GLUfuncptr CallBackFunc);
+GLAPI void GLAPIENTRY gluTessEndContour (GLUtesselator* tess);
+GLAPI void GLAPIENTRY gluTessEndPolygon (GLUtesselator* tess);
+GLAPI void GLAPIENTRY gluTessNormal (GLUtesselator* tess, GLdouble valueX, GLdouble valueY, GLdouble valueZ);
+GLAPI void GLAPIENTRY gluTessProperty (GLUtesselator* tess, GLenum which, GLdouble data);
+GLAPI void GLAPIENTRY gluTessVertex (GLUtesselator* tess, GLdouble *location, GLvoid* data);
+
+/* ErrorCode */
+#define GLU_INVALID_ENUM 100900
+#define GLU_INVALID_VALUE 100901
+#define GLU_OUT_OF_MEMORY 100902
+
+/* TessCallback */
+#define GLU_TESS_BEGIN 100100
+#define GLU_BEGIN 100100
+#define GLU_TESS_VERTEX 100101
+#define GLU_VERTEX 100101
+#define GLU_TESS_END 100102
+#define GLU_END 100102
+#define GLU_TESS_ERROR 100103
+#define GLU_TESS_EDGE_FLAG 100104
+#define GLU_EDGE_FLAG 100104
+#define GLU_TESS_COMBINE 100105
+#define GLU_TESS_BEGIN_DATA 100106
+#define GLU_TESS_VERTEX_DATA 100107
+#define GLU_TESS_END_DATA 100108
+#define GLU_TESS_ERROR_DATA 100109
+#define GLU_TESS_EDGE_FLAG_DATA 100110
+#define GLU_TESS_COMBINE_DATA 100111
+
+/* TessContour */
+#define GLU_CW 100120
+#define GLU_CCW 100121
+#define GLU_INTERIOR 100122
+#define GLU_EXTERIOR 100123
+#define GLU_UNKNOWN 100124
+
+/* TessProperty */
+#define GLU_TESS_WINDING_RULE 100140
+#define GLU_TESS_BOUNDARY_ONLY 100141
+#define GLU_TESS_TOLERANCE 100142
+
+/* TessError */
+#define GLU_TESS_ERROR1 100151
+#define GLU_TESS_ERROR2 100152
+#define GLU_TESS_ERROR3 100153
+#define GLU_TESS_ERROR4 100154
+#define GLU_TESS_ERROR5 100155
+#define GLU_TESS_ERROR6 100156
+#define GLU_TESS_ERROR7 100157
+#define GLU_TESS_ERROR8 100158
+#define GLU_TESS_MISSING_BEGIN_POLYGON 100151
+#define GLU_TESS_MISSING_BEGIN_CONTOUR 100152
+#define GLU_TESS_MISSING_END_POLYGON 100153
+#define GLU_TESS_MISSING_END_CONTOUR 100154
+#define GLU_TESS_COORD_TOO_LARGE 100155
+#define GLU_TESS_NEED_COMBINE_CALLBACK 100156
+
+/* TessWinding */
+#define GLU_TESS_WINDING_ODD 100130
+#define GLU_TESS_WINDING_NONZERO 100131
+#define GLU_TESS_WINDING_POSITIVE 100132
+#define GLU_TESS_WINDING_NEGATIVE 100133
+#define GLU_TESS_WINDING_ABS_GEQ_TWO 100134
+
+#endif /* __TESSELATOR_H__ */
diff --git a/cogl/tesselator/tessmono.c b/cogl/tesselator/tessmono.c
new file mode 100644
index 000000000..4d0844005
--- /dev/null
+++ b/cogl/tesselator/tessmono.c
@@ -0,0 +1,201 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#include "gluos.h"
+#include
+#include "geom.h"
+#include "mesh.h"
+#include "tessmono.h"
+#include
+
+#define AddWinding(eDst,eSrc) (eDst->winding += eSrc->winding, \
+ eDst->Sym->winding += eSrc->Sym->winding)
+
+/* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
+ * (what else would it do??) The region must consist of a single
+ * loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
+ * case means that any vertical line intersects the interior of the
+ * region in a single interval.
+ *
+ * Tessellation consists of adding interior edges (actually pairs of
+ * half-edges), to split the region into non-overlapping triangles.
+ *
+ * The basic idea is explained in Preparata and Shamos (which I don''t
+ * have handy right now), although their implementation is more
+ * complicated than this one. The are two edge chains, an upper chain
+ * and a lower chain. We process all vertices from both chains in order,
+ * from right to left.
+ *
+ * The algorithm ensures that the following invariant holds after each
+ * vertex is processed: the untessellated region consists of two
+ * chains, where one chain (say the upper) is a single edge, and
+ * the other chain is concave. The left vertex of the single edge
+ * is always to the left of all vertices in the concave chain.
+ *
+ * Each step consists of adding the rightmost unprocessed vertex to one
+ * of the two chains, and forming a fan of triangles from the rightmost
+ * of two chain endpoints. Determining whether we can add each triangle
+ * to the fan is a simple orientation test. By making the fan as large
+ * as possible, we restore the invariant (check it yourself).
+ */
+int __gl_meshTessellateMonoRegion( GLUface *face )
+{
+ GLUhalfEdge *up, *lo;
+
+ /* All edges are oriented CCW around the boundary of the region.
+ * First, find the half-edge whose origin vertex is rightmost.
+ * Since the sweep goes from left to right, face->anEdge should
+ * be close to the edge we want.
+ */
+ up = face->anEdge;
+ assert( up->Lnext != up && up->Lnext->Lnext != up );
+
+ for( ; VertLeq( up->Dst, up->Org ); up = up->Lprev )
+ ;
+ for( ; VertLeq( up->Org, up->Dst ); up = up->Lnext )
+ ;
+ lo = up->Lprev;
+
+ while( up->Lnext != lo ) {
+ if( VertLeq( up->Dst, lo->Org )) {
+ /* up->Dst is on the left. It is safe to form triangles from lo->Org.
+ * The EdgeGoesLeft test guarantees progress even when some triangles
+ * are CW, given that the upper and lower chains are truly monotone.
+ */
+ while( lo->Lnext != up && (EdgeGoesLeft( lo->Lnext )
+ || EdgeSign( lo->Org, lo->Dst, lo->Lnext->Dst ) <= 0 )) {
+ GLUhalfEdge *tempHalfEdge= __gl_meshConnect( lo->Lnext, lo );
+ if (tempHalfEdge == NULL) return 0;
+ lo = tempHalfEdge->Sym;
+ }
+ lo = lo->Lprev;
+ } else {
+ /* lo->Org is on the left. We can make CCW triangles from up->Dst. */
+ while( lo->Lnext != up && (EdgeGoesRight( up->Lprev )
+ || EdgeSign( up->Dst, up->Org, up->Lprev->Org ) >= 0 )) {
+ GLUhalfEdge *tempHalfEdge= __gl_meshConnect( up, up->Lprev );
+ if (tempHalfEdge == NULL) return 0;
+ up = tempHalfEdge->Sym;
+ }
+ up = up->Lnext;
+ }
+ }
+
+ /* Now lo->Org == up->Dst == the leftmost vertex. The remaining region
+ * can be tessellated in a fan from this leftmost vertex.
+ */
+ assert( lo->Lnext != up );
+ while( lo->Lnext->Lnext != up ) {
+ GLUhalfEdge *tempHalfEdge= __gl_meshConnect( lo->Lnext, lo );
+ if (tempHalfEdge == NULL) return 0;
+ lo = tempHalfEdge->Sym;
+ }
+
+ return 1;
+}
+
+
+/* __gl_meshTessellateInterior( mesh ) tessellates each region of
+ * the mesh which is marked "inside" the polygon. Each such region
+ * must be monotone.
+ */
+int __gl_meshTessellateInterior( GLUmesh *mesh )
+{
+ GLUface *f, *next;
+
+ /*LINTED*/
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = next ) {
+ /* Make sure we don''t try to tessellate the new triangles. */
+ next = f->next;
+ if( f->inside ) {
+ if ( !__gl_meshTessellateMonoRegion( f ) ) return 0;
+ }
+ }
+
+ return 1;
+}
+
+
+/* __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
+ * which are not marked "inside" the polygon. Since further mesh operations
+ * on NULL faces are not allowed, the main purpose is to clean up the
+ * mesh so that exterior loops are not represented in the data structure.
+ */
+void __gl_meshDiscardExterior( GLUmesh *mesh )
+{
+ GLUface *f, *next;
+
+ /*LINTED*/
+ for( f = mesh->fHead.next; f != &mesh->fHead; f = next ) {
+ /* Since f will be destroyed, save its next pointer. */
+ next = f->next;
+ if( ! f->inside ) {
+ __gl_meshZapFace( f );
+ }
+ }
+}
+
+#define MARKED_FOR_DELETION 0x7fffffff
+
+/* __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
+ * winding numbers on all edges so that regions marked "inside" the
+ * polygon have a winding number of "value", and regions outside
+ * have a winding number of 0.
+ *
+ * If keepOnlyBoundary is TRUE, it also deletes all edges which do not
+ * separate an interior region from an exterior one.
+ */
+int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
+ GLboolean keepOnlyBoundary )
+{
+ GLUhalfEdge *e, *eNext;
+
+ for( e = mesh->eHead.next; e != &mesh->eHead; e = eNext ) {
+ eNext = e->next;
+ if( e->Rface->inside != e->Lface->inside ) {
+
+ /* This is a boundary edge (one side is interior, one is exterior). */
+ e->winding = (e->Lface->inside) ? value : -value;
+ } else {
+
+ /* Both regions are interior, or both are exterior. */
+ if( ! keepOnlyBoundary ) {
+ e->winding = 0;
+ } else {
+ if ( !__gl_meshDelete( e ) ) return 0;
+ }
+ }
+ }
+ return 1;
+}
diff --git a/cogl/tesselator/tessmono.h b/cogl/tesselator/tessmono.h
new file mode 100644
index 000000000..8ee1b2fe3
--- /dev/null
+++ b/cogl/tesselator/tessmono.h
@@ -0,0 +1,71 @@
+/*
+ * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
+ * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice including the dates of first publication and
+ * either this permission notice or a reference to
+ * http://oss.sgi.com/projects/FreeB/
+ * shall be included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
+ * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Silicon Graphics, Inc.
+ * shall not be used in advertising or otherwise to promote the sale, use or
+ * other dealings in this Software without prior written authorization from
+ * Silicon Graphics, Inc.
+ */
+/*
+** Author: Eric Veach, July 1994.
+**
+*/
+
+#ifndef __tessmono_h_
+#define __tessmono_h_
+
+/* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
+ * (what else would it do??) The region must consist of a single
+ * loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
+ * case means that any vertical line intersects the interior of the
+ * region in a single interval.
+ *
+ * Tessellation consists of adding interior edges (actually pairs of
+ * half-edges), to split the region into non-overlapping triangles.
+ *
+ * __gl_meshTessellateInterior( mesh ) tessellates each region of
+ * the mesh which is marked "inside" the polygon. Each such region
+ * must be monotone.
+ *
+ * __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
+ * which are not marked "inside" the polygon. Since further mesh operations
+ * on NULL faces are not allowed, the main purpose is to clean up the
+ * mesh so that exterior loops are not represented in the data structure.
+ *
+ * __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
+ * winding numbers on all edges so that regions marked "inside" the
+ * polygon have a winding number of "value", and regions outside
+ * have a winding number of 0.
+ *
+ * If keepOnlyBoundary is TRUE, it also deletes all edges which do not
+ * separate an interior region from an exterior one.
+ */
+
+int __gl_meshTessellateMonoRegion( GLUface *face );
+int __gl_meshTessellateInterior( GLUmesh *mesh );
+void __gl_meshDiscardExterior( GLUmesh *mesh );
+int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
+ GLboolean keepOnlyBoundary );
+
+#endif