1/*
2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice including the dates of first publication and
13 * either this permission notice or a reference to
14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * Except as contained in this notice, the name of Silicon Graphics, Inc.
26 * shall not be used in advertising or otherwise to promote the sale, use or
27 * other dealings in this Software without prior written authorization from
28 * Silicon Graphics, Inc.
29 */
30/*
31** Author: Eric Veach, July 1994.
32**
33*/
34
35#ifndef __tess_h_
36#define __tess_h_
37
38#include <GL/glu.h>
39#include <setjmp.h>
40#include "mesh.h"
41#include "dict.h"
42#include "priorityq.h"
43
44/* The begin/end calls must be properly nested.  We keep track of
45 * the current state to enforce the ordering.
46 */
47enum TessState { T_DORMANT, T_IN_POLYGON, T_IN_CONTOUR };
48
49/* We cache vertex data for single-contour polygons so that we can
50 * try a quick-and-dirty decomposition first.
51 */
52#define TESS_MAX_CACHE	100
53
54typedef struct CachedVertex {
55  GLdouble	coords[3];
56  void		*data;
57} CachedVertex;
58
59struct GLUtesselator {
60
61  /*** state needed for collecting the input data ***/
62
63  enum TessState state;		/* what begin/end calls have we seen? */
64
65  GLUhalfEdge	*lastEdge;	/* lastEdge->Org is the most recent vertex */
66  GLUmesh	*mesh;		/* stores the input contours, and eventually
67                                   the tessellation itself */
68
69  void		(GLAPIENTRY *callError)( GLenum errnum );
70
71  /*** state needed for projecting onto the sweep plane ***/
72
73  GLdouble	normal[3];	/* user-specified normal (if provided) */
74  GLdouble	sUnit[3];	/* unit vector in s-direction (debugging) */
75  GLdouble	tUnit[3];	/* unit vector in t-direction (debugging) */
76
77  /*** state needed for the line sweep ***/
78
79  GLdouble	relTolerance;	/* tolerance for merging features */
80  GLenum	windingRule;	/* rule for determining polygon interior */
81  GLboolean	fatalError;	/* fatal error: needed combine callback */
82
83  Dict		*dict;		/* edge dictionary for sweep line */
84  PriorityQ	*pq;		/* priority queue of vertex events */
85  GLUvertex	*event;		/* current sweep event being processed */
86
87  void		(GLAPIENTRY *callCombine)( GLdouble coords[3], void *data[4],
88			        GLfloat weight[4], void **outData );
89
90  /*** state needed for rendering callbacks (see render.c) ***/
91
92  GLboolean	flagBoundary;	/* mark boundary edges (use EdgeFlag) */
93  GLboolean	boundaryOnly;	/* Extract contours, not triangles */
94  GLUface	*lonelyTriList;
95    /* list of triangles which could not be rendered as strips or fans */
96
97  void		(GLAPIENTRY *callBegin)( GLenum type );
98  void		(GLAPIENTRY *callEdgeFlag)( GLboolean boundaryEdge );
99  void		(GLAPIENTRY *callVertex)( void *data );
100  void		(GLAPIENTRY *callEnd)( void );
101  void		(GLAPIENTRY *callMesh)( GLUmesh *mesh );
102
103
104  /*** state needed to cache single-contour polygons for renderCache() */
105
106  GLboolean	emptyCache;		/* empty cache on next vertex() call */
107  int		cacheCount;		/* number of cached vertices */
108  CachedVertex	cache[TESS_MAX_CACHE];	/* the vertex data */
109
110  /*** rendering callbacks that also pass polygon data  ***/
111  void		(GLAPIENTRY *callBeginData)( GLenum type, void *polygonData );
112  void		(GLAPIENTRY *callEdgeFlagData)( GLboolean boundaryEdge,
113				     void *polygonData );
114  void		(GLAPIENTRY *callVertexData)( void *data, void *polygonData );
115  void		(GLAPIENTRY *callEndData)( void *polygonData );
116  void		(GLAPIENTRY *callErrorData)( GLenum errnum, void *polygonData );
117  void		(GLAPIENTRY *callCombineData)( GLdouble coords[3], void *data[4],
118				    GLfloat weight[4], void **outData,
119				    void *polygonData );
120
121  jmp_buf env;			/* place to jump to when memAllocs fail */
122
123  void *polygonData;		/* client data for current polygon */
124};
125
126void GLAPIENTRY __gl_noBeginData( GLenum type, void *polygonData );
127void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge, void *polygonData );
128void GLAPIENTRY __gl_noVertexData( void *data, void *polygonData );
129void GLAPIENTRY __gl_noEndData( void *polygonData );
130void GLAPIENTRY __gl_noErrorData( GLenum errnum, void *polygonData );
131void GLAPIENTRY __gl_noCombineData( GLdouble coords[3], void *data[4],
132			 GLfloat weight[4], void **outData,
133			 void *polygonData );
134
135#define CALL_BEGIN_OR_BEGIN_DATA(a) \
136   if (tess->callBeginData != &__gl_noBeginData) \
137      (*tess->callBeginData)((a),tess->polygonData); \
138   else (*tess->callBegin)((a));
139
140#define CALL_VERTEX_OR_VERTEX_DATA(a) \
141   if (tess->callVertexData != &__gl_noVertexData) \
142      (*tess->callVertexData)((a),tess->polygonData); \
143   else (*tess->callVertex)((a));
144
145#define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
146   if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
147      (*tess->callEdgeFlagData)((a),tess->polygonData); \
148   else (*tess->callEdgeFlag)((a));
149
150#define CALL_END_OR_END_DATA() \
151   if (tess->callEndData != &__gl_noEndData) \
152      (*tess->callEndData)(tess->polygonData); \
153   else (*tess->callEnd)();
154
155#define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
156   if (tess->callCombineData != &__gl_noCombineData) \
157      (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
158   else (*tess->callCombine)((a),(b),(c),(d));
159
160#define CALL_ERROR_OR_ERROR_DATA(a) \
161   if (tess->callErrorData != &__gl_noErrorData) \
162      (*tess->callErrorData)((a),tess->polygonData); \
163   else (*tess->callError)((a));
164
165#endif
166