7365c3aa77
This splits out the cogl_path_ api into a separate cogl-path sub-library
like cogl-pango and cogl-gst. This enables developers to build Cogl with
this sub-library disabled if they don't need it which can be useful when
its important to keep the size of an application and its dependencies
down to a minimum. The functions cogl_framebuffer_{fill,stroke}_path
have been renamed to cogl_path_{fill,stroke}.
There were a few places in core cogl and cogl-gst that referenced the
CoglPath api and these have been decoupled by using the CoglPrimitive
api instead. In the case of cogl_framebuffer_push_path_clip() the core
clip stack no longer accepts path clips directly but it's now possible
to get a CoglPrimitive for the fill of a path and so the implementation
of cogl_framebuffer_push_path_clip() now lives in cogl-path and works as
a shim that first gets a CoglPrimitive and uses
cogl_framebuffer_push_primitive_clip instead.
We may want to consider renaming cogl_framebuffer_push_path_clip to
put it in the cogl_path_ namespace.
Reviewed-by: Neil Roberts <neil@linux.intel.com>
(cherry picked from commit 8aadfd829239534fb4ec8255cdea813d698c5a3f)
So as to avoid breaking the 1.x API or even the ABI since we are quite
late in the 1.16 development cycle the patch was modified to build
cogl-path as a noinst_LTLIBRARY before building cogl and link the code
directly into libcogl.so as it was previously. This way we can wait
until the start of the 1.18 cycle before splitting the code into a
separate libcogl-path.so.
This also adds shims for cogl_framebuffer_fill/stroke_path() to avoid
breaking the 1.x API/ABI.
267 lines
12 KiB
C
267 lines
12 KiB
C
/*
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* SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
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* Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice including the dates of first publication and
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* either this permission notice or a reference to
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* http://oss.sgi.com/projects/FreeB/
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* shall be included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
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* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
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* OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*
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* Except as contained in this notice, the name of Silicon Graphics, Inc.
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* shall not be used in advertising or otherwise to promote the sale, use or
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* other dealings in this Software without prior written authorization from
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* Silicon Graphics, Inc.
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*/
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/*
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** Author: Eric Veach, July 1994.
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**
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*/
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#ifndef __mesh_h_
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#define __mesh_h_
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#include <GL/glu.h>
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typedef struct GLUmesh GLUmesh;
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typedef struct GLUvertex GLUvertex;
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typedef struct GLUface GLUface;
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typedef struct GLUhalfEdge GLUhalfEdge;
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typedef struct ActiveRegion ActiveRegion; /* Internal data */
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/* The mesh structure is similar in spirit, notation, and operations
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* to the "quad-edge" structure (see L. Guibas and J. Stolfi, Primitives
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* for the manipulation of general subdivisions and the computation of
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* Voronoi diagrams, ACM Transactions on Graphics, 4(2):74-123, April 1985).
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* For a simplified description, see the course notes for CS348a,
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* "Mathematical Foundations of Computer Graphics", available at the
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* Stanford bookstore (and taught during the fall quarter).
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* The implementation also borrows a tiny subset of the graph-based approach
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* use in Mantyla's Geometric Work Bench (see M. Mantyla, An Introduction
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* to Sold Modeling, Computer Science Press, Rockville, Maryland, 1988).
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*
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* The fundamental data structure is the "half-edge". Two half-edges
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* go together to make an edge, but they point in opposite directions.
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* Each half-edge has a pointer to its mate (the "symmetric" half-edge Sym),
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* its origin vertex (Org), the face on its left side (Lface), and the
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* adjacent half-edges in the CCW direction around the origin vertex
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* (Onext) and around the left face (Lnext). There is also a "next"
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* pointer for the global edge list (see below).
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*
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* The notation used for mesh navigation:
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* Sym = the mate of a half-edge (same edge, but opposite direction)
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* Onext = edge CCW around origin vertex (keep same origin)
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* Dnext = edge CCW around destination vertex (keep same dest)
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* Lnext = edge CCW around left face (dest becomes new origin)
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* Rnext = edge CCW around right face (origin becomes new dest)
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*
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* "prev" means to substitute CW for CCW in the definitions above.
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*
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* The mesh keeps global lists of all vertices, faces, and edges,
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* stored as doubly-linked circular lists with a dummy header node.
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* The mesh stores pointers to these dummy headers (vHead, fHead, eHead).
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*
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* The circular edge list is special; since half-edges always occur
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* in pairs (e and e->Sym), each half-edge stores a pointer in only
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* one direction. Starting at eHead and following the e->next pointers
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* will visit each *edge* once (ie. e or e->Sym, but not both).
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* e->Sym stores a pointer in the opposite direction, thus it is
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* always true that e->Sym->next->Sym->next == e.
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*
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* Each vertex has a pointer to next and previous vertices in the
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* circular list, and a pointer to a half-edge with this vertex as
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* the origin (NULL if this is the dummy header). There is also a
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* field "data" for client data.
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*
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* Each face has a pointer to the next and previous faces in the
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* circular list, and a pointer to a half-edge with this face as
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* the left face (NULL if this is the dummy header). There is also
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* a field "data" for client data.
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*
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* Note that what we call a "face" is really a loop; faces may consist
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* of more than one loop (ie. not simply connected), but there is no
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* record of this in the data structure. The mesh may consist of
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* several disconnected regions, so it may not be possible to visit
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* the entire mesh by starting at a half-edge and traversing the edge
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* structure.
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*
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* The mesh does NOT support isolated vertices; a vertex is deleted along
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* with its last edge. Similarly when two faces are merged, one of the
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* faces is deleted (see __gl_meshDelete below). For mesh operations,
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* all face (loop) and vertex pointers must not be NULL. However, once
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* mesh manipulation is finished, __gl_MeshZapFace can be used to delete
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* faces of the mesh, one at a time. All external faces can be "zapped"
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* before the mesh is returned to the client; then a NULL face indicates
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* a region which is not part of the output polygon.
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*/
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struct GLUvertex {
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GLUvertex *next; /* next vertex (never NULL) */
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GLUvertex *prev; /* previous vertex (never NULL) */
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GLUhalfEdge *anEdge; /* a half-edge with this origin */
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void *data; /* client's data */
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/* Internal data (keep hidden) */
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GLdouble coords[3]; /* vertex location in 3D */
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GLdouble s, t; /* projection onto the sweep plane */
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long pqHandle; /* to allow deletion from priority queue */
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};
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struct GLUface {
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GLUface *next; /* next face (never NULL) */
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GLUface *prev; /* previous face (never NULL) */
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GLUhalfEdge *anEdge; /* a half edge with this left face */
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void *data; /* room for client's data */
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/* Internal data (keep hidden) */
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GLUface *trail; /* "stack" for conversion to strips */
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GLboolean marked; /* flag for conversion to strips */
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GLboolean inside; /* this face is in the polygon interior */
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};
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struct GLUhalfEdge {
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GLUhalfEdge *next; /* doubly-linked list (prev==Sym->next) */
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GLUhalfEdge *Sym; /* same edge, opposite direction */
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GLUhalfEdge *Onext; /* next edge CCW around origin */
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GLUhalfEdge *Lnext; /* next edge CCW around left face */
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GLUvertex *Org; /* origin vertex (Overtex too long) */
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GLUface *Lface; /* left face */
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/* Internal data (keep hidden) */
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ActiveRegion *activeRegion; /* a region with this upper edge (sweep.c) */
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int winding; /* change in winding number when crossing
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from the right face to the left face */
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};
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#define Rface Sym->Lface
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#define Dst Sym->Org
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#define Oprev Sym->Lnext
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#define Lprev Onext->Sym
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#define Dprev Lnext->Sym
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#define Rprev Sym->Onext
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#define Dnext Rprev->Sym /* 3 pointers */
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#define Rnext Oprev->Sym /* 3 pointers */
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struct GLUmesh {
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GLUvertex vHead; /* dummy header for vertex list */
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GLUface fHead; /* dummy header for face list */
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GLUhalfEdge eHead; /* dummy header for edge list */
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GLUhalfEdge eHeadSym; /* and its symmetric counterpart */
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};
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/* The mesh operations below have three motivations: completeness,
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* convenience, and efficiency. The basic mesh operations are MakeEdge,
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* Splice, and Delete. All the other edge operations can be implemented
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* in terms of these. The other operations are provided for convenience
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* and/or efficiency.
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*
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* When a face is split or a vertex is added, they are inserted into the
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* global list *before* the existing vertex or face (ie. e->Org or e->Lface).
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* This makes it easier to process all vertices or faces in the global lists
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* without worrying about processing the same data twice. As a convenience,
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* when a face is split, the "inside" flag is copied from the old face.
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* Other internal data (v->data, v->activeRegion, f->data, f->marked,
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* f->trail, e->winding) is set to zero.
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*
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* ********************** Basic Edge Operations **************************
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*
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* __gl_meshMakeEdge( mesh ) creates one edge, two vertices, and a loop.
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* The loop (face) consists of the two new half-edges.
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*
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* __gl_meshSplice( eOrg, eDst ) is the basic operation for changing the
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* mesh connectivity and topology. It changes the mesh so that
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* eOrg->Onext <- OLD( eDst->Onext )
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* eDst->Onext <- OLD( eOrg->Onext )
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* where OLD(...) means the value before the meshSplice operation.
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*
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* This can have two effects on the vertex structure:
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* - if eOrg->Org != eDst->Org, the two vertices are merged together
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* - if eOrg->Org == eDst->Org, the origin is split into two vertices
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* In both cases, eDst->Org is changed and eOrg->Org is untouched.
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*
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* Similarly (and independently) for the face structure,
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* - if eOrg->Lface == eDst->Lface, one loop is split into two
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* - if eOrg->Lface != eDst->Lface, two distinct loops are joined into one
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* In both cases, eDst->Lface is changed and eOrg->Lface is unaffected.
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*
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* __gl_meshDelete( eDel ) removes the edge eDel. There are several cases:
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* if (eDel->Lface != eDel->Rface), we join two loops into one; the loop
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* eDel->Lface is deleted. Otherwise, we are splitting one loop into two;
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* the newly created loop will contain eDel->Dst. If the deletion of eDel
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* would create isolated vertices, those are deleted as well.
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*
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* ********************** Other Edge Operations **************************
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*
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* __gl_meshAddEdgeVertex( eOrg ) creates a new edge eNew such that
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* eNew == eOrg->Lnext, and eNew->Dst is a newly created vertex.
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* eOrg and eNew will have the same left face.
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*
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* __gl_meshSplitEdge( eOrg ) splits eOrg into two edges eOrg and eNew,
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* such that eNew == eOrg->Lnext. The new vertex is eOrg->Dst == eNew->Org.
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* eOrg and eNew will have the same left face.
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*
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* __gl_meshConnect( eOrg, eDst ) creates a new edge from eOrg->Dst
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* to eDst->Org, and returns the corresponding half-edge eNew.
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* If eOrg->Lface == eDst->Lface, this splits one loop into two,
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* and the newly created loop is eNew->Lface. Otherwise, two disjoint
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* loops are merged into one, and the loop eDst->Lface is destroyed.
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*
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* ************************ Other Operations *****************************
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*
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* __gl_meshNewMesh() creates a new mesh with no edges, no vertices,
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* and no loops (what we usually call a "face").
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*
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* __gl_meshUnion( mesh1, mesh2 ) forms the union of all structures in
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* both meshes, and returns the new mesh (the old meshes are destroyed).
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*
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* __gl_meshDeleteMesh( mesh ) will free all storage for any valid mesh.
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*
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* __gl_meshZapFace( fZap ) destroys a face and removes it from the
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* global face list. All edges of fZap will have a NULL pointer as their
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* left face. Any edges which also have a NULL pointer as their right face
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* are deleted entirely (along with any isolated vertices this produces).
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* An entire mesh can be deleted by zapping its faces, one at a time,
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* in any order. Zapped faces cannot be used in further mesh operations!
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*
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* __gl_meshCheckMesh( mesh ) checks a mesh for self-consistency.
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*/
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GLUhalfEdge *__gl_meshMakeEdge( GLUmesh *mesh );
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int __gl_meshSplice( GLUhalfEdge *eOrg, GLUhalfEdge *eDst );
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int __gl_meshDelete( GLUhalfEdge *eDel );
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GLUhalfEdge *__gl_meshAddEdgeVertex( GLUhalfEdge *eOrg );
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GLUhalfEdge *__gl_meshSplitEdge( GLUhalfEdge *eOrg );
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GLUhalfEdge *__gl_meshConnect( GLUhalfEdge *eOrg, GLUhalfEdge *eDst );
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GLUmesh *__gl_meshNewMesh( void );
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GLUmesh *__gl_meshUnion( GLUmesh *mesh1, GLUmesh *mesh2 );
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void __gl_meshDeleteMesh( GLUmesh *mesh );
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void __gl_meshZapFace( GLUface *fZap );
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#ifdef NDEBUG
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#define __gl_meshCheckMesh( mesh )
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#else
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void __gl_meshCheckMesh( GLUmesh *mesh );
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#endif
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#endif
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