brl/mutter
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cogl: Pull in the code for GLU tesselator from Mesa/SGI

Browse Source 
This copies the files for the GLU tesselator from Mesa. The Mesa code
is based on the original SGI code and is released under a BSD license.

The memalloc.h header has been replaced with one that forces the code
to use g_malloc and friends. The rest of the files are not altered
from the original so it should be possible to later upgrade the files
by simply overwriting them.

There is a tesselator.h header which is expected to be included by
rest of Cogl to use the tesselator. This contains a trimmed down
version of glu.h that only includes parts that pertain to the
tesselator. There is also a stub glu.h in the GL directory which is
just provided so that the tesselator code can include <GL/gl.h>
without depending on the system header. It just redirects to
tesselator.h
This commit is contained in:
Neil Roberts 2010-04-16 00:28:15 +01:00
parent d99a8bf694
commit b86e330957
29 changed files with 6601 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
cogl/Makefile.am
View File

@ -2,7 +2,7 @@ include $(top_srcdir)/build/autotools/Makefile.am.silent
NULL = NULL =
SUBDIRS = driver SUBDIRS = driver tesselator
BUILT_SOURCES = BUILT_SOURCES =
EXTRA_DIST = EXTRA_DIST =
@ -159,7 +159,10 @@ include $(top_srcdir)/build/autotools/Makefile.am.enums
noinst_LTLIBRARIES = libclutter-cogl.la 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) libclutter_cogl_la_SOURCES = $(BUILT_SOURCES) $(cogl_sources_c)

26
cogl/tesselator/GL/glu.h Normal file
View File

@ -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 <http://www.gnu.org/licenses/>.
*
*/
/* This is just a wrapper to use our simplified version of glu.h so
that the tesselator code can still #include <GL/glu.h> */
#include "../tesselator.h"

41
cogl/tesselator/Makefile.am Normal file
View File

@ -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

446
cogl/tesselator/README Normal file
View File

@ -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

100
cogl/tesselator/dict-list.h Normal file
View File

@ -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

111
cogl/tesselator/dict.c Normal file
View File

@ -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 <stddef.h>
#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;
}

100
cogl/tesselator/dict.h Normal file
View File

@ -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

264
cogl/tesselator/geom.c Normal file
View File

@ -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 <assert.h>
#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 <stdlib.h>
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 );
}
}

84
cogl/tesselator/geom.h Normal file
View File

@ -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

1
cogl/tesselator/gluos.h Normal file
View File

@ -0,0 +1 @@
/* This is a stub header to avoid having to change tess.c */

42
cogl/tesselator/memalloc.h Normal file
View File

@ -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 <http://www.gnu.org/licenses/>.
*
*
*/
/* 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 <glib.h>
#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__ */

794
cogl/tesselator/mesh.c Normal file
View File

@ -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 <stddef.h>
#include <assert.h>
#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

266
cogl/tesselator/mesh.h Normal file
View File

@ -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 <GL/glu.h>
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

253
cogl/tesselator/normal.c Normal file
View File

@ -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 <math.h>
#include <assert.h>
#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 <stdlib.h>
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 );
}
}

45
cogl/tesselator/normal.h Normal file
View File

@ -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

252
cogl/tesselator/priorityq-heap.c Normal file
View File

@ -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 <stddef.h>
#include <assert.h>
#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;
}

107
cogl/tesselator/priorityq-heap.h Normal file
View File

@ -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

117
cogl/tesselator/priorityq-sort.h Normal file
View File

@ -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

260
cogl/tesselator/priorityq.c Normal file
View File

@ -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 <stddef.h>
#include <assert.h>
#include <limits.h> /* 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;
}
}

117
cogl/tesselator/priorityq.h Normal file
View File

@ -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

498
cogl/tesselator/render.c Normal file
View File

@ -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 <assert.h>
#include <stddef.h>
#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;
}

52
cogl/tesselator/render.h Normal file
View File

@ -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

1357
cogl/tesselator/sweep.c Normal file
View File

File diff suppressed because it is too large Load Diff

77
cogl/tesselator/sweep.h Normal file
View File

@ -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

628
cogl/tesselator/tess.c Normal file
View File

@ -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 <stddef.h>
#include <assert.h>
#include <setjmp.h>
#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 );
}

165
cogl/tesselator/tess.h Normal file
View File

@ -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 <GL/glu.h>
#include <setjmp.h>
#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

121
cogl/tesselator/tesselator.h Normal file
View File

@ -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__ */

201
cogl/tesselator/tessmono.c Normal file
View File

@ -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 <stdlib.h>
#include "geom.h"
#include "mesh.h"
#include "tessmono.h"
#include <assert.h>
#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;
}

71
cogl/tesselator/tessmono.h Normal file
View File

@ -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