1/*
2** License Applicability. Except to the extent portions of this file are
3** made subject to an alternative license as permitted in the SGI Free
4** Software License B, Version 1.1 (the "License"), the contents of this
5** file are subject only to the provisions of the License. You may not use
6** this file except in compliance with the License. You may obtain a copy
7** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
8** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
9**
10** http://oss.sgi.com/projects/FreeB
11**
12** Note that, as provided in the License, the Software is distributed on an
13** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
14** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
15** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
16** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
17**
18** Original Code. The Original Code is: OpenGL Sample Implementation,
19** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
20** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
21** Copyright in any portions created by third parties is as indicated
22** elsewhere herein. All Rights Reserved.
23**
24** Additional Notice Provisions: The application programming interfaces
25** established by SGI in conjunction with the Original Code are The
26** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
27** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
28** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
29** Window System(R) (Version 1.3), released October 19, 1998. This software
30** was created using the OpenGL(R) version 1.2.1 Sample Implementation
31** published by SGI, but has not been independently verified as being
32** compliant with the OpenGL(R) version 1.2.1 Specification.
33**
34*/
35/*
36** Author: Eric Veach, July 1994.
37**
38** $Date$ $Revision$
39** $Header: //depot/main/gfx/lib/glu/libtess/tess.h#6 $
40*/
41
42#ifndef __tess_h_
43#define __tess_h_
44
45#include <sk_glu.h>
46#include <setjmp.h>
47#include "mesh.h"
48#include "dict.h"
49#include "priorityq.h"
50
51/* The begin/end calls must be properly nested.  We keep track of
52 * the current state to enforce the ordering.
53 */
54enum TessState { T_DORMANT, T_IN_POLYGON, T_IN_CONTOUR };
55
56/* We cache vertex data for single-contour polygons so that we can
57 * try a quick-and-dirty decomposition first.
58 */
59#define TESS_MAX_CACHE	100
60
61typedef struct CachedVertex {
62  GLdouble	coords[3];
63  void		*data;
64} CachedVertex;
65
66struct GLUtesselator {
67
68  /*** state needed for collecting the input data ***/
69
70  enum TessState state;		/* what begin/end calls have we seen? */
71
72  GLUhalfEdge	*lastEdge;	/* lastEdge->Org is the most recent vertex */
73  GLUmesh	*mesh;		/* stores the input contours, and eventually
74                                   the tessellation itself */
75
76  void		(GLAPIENTRY *callError)( GLenum errnum );
77
78  /*** state needed for projecting onto the sweep plane ***/
79
80  GLdouble	normal[3];	/* user-specified normal (if provided) */
81  GLdouble	sUnit[3];	/* unit vector in s-direction (debugging) */
82  GLdouble	tUnit[3];	/* unit vector in t-direction (debugging) */
83
84  /*** state needed for the line sweep ***/
85
86  GLdouble	relTolerance;	/* tolerance for merging features */
87  GLenum	windingRule;	/* rule for determining polygon interior */
88  GLboolean	fatalError;	/* fatal error: needed combine callback */
89
90  Dict		*dict;		/* edge dictionary for sweep line */
91  PriorityQ	*pq;		/* priority queue of vertex events */
92  GLUvertex	*event;		/* current sweep event being processed */
93
94  void		(GLAPIENTRY *callCombine)( GLdouble coords[3], void *data[4],
95			        GLfloat weight[4], void **outData );
96
97  /*** state needed for rendering callbacks (see render.c) ***/
98
99  GLboolean	flagBoundary;	/* mark boundary edges (use EdgeFlag) */
100  GLboolean	boundaryOnly;	/* Extract contours, not triangles */
101  GLUface	*lonelyTriList;
102    /* list of triangles which could not be rendered as strips or fans */
103
104  void		(GLAPIENTRY *callBegin)( GLenum type );
105  void		(GLAPIENTRY *callEdgeFlag)( GLboolean boundaryEdge );
106  void		(GLAPIENTRY *callVertex)( void *data );
107  void		(GLAPIENTRY *callEnd)( void );
108  void		(GLAPIENTRY *callMesh)( GLUmesh *mesh );
109
110
111  /*** state needed to cache single-contour polygons for renderCache() */
112
113  GLboolean	emptyCache;		/* empty cache on next vertex() call */
114  int		cacheCount;		/* number of cached vertices */
115  CachedVertex	cache[TESS_MAX_CACHE];	/* the vertex data */
116
117  /*** rendering callbacks that also pass polygon data  ***/
118  void		(GLAPIENTRY *callBeginData)( GLenum type, void *polygonData );
119  void		(GLAPIENTRY *callEdgeFlagData)( GLboolean boundaryEdge,
120				     void *polygonData );
121  void		(GLAPIENTRY *callVertexData)( void *data, void *polygonData );
122  void		(GLAPIENTRY *callEndData)( void *polygonData );
123  void		(GLAPIENTRY *callErrorData)( GLenum errnum, void *polygonData );
124  void		(GLAPIENTRY *callCombineData)( GLdouble coords[3], void *data[4],
125				    GLfloat weight[4], void **outData,
126				    void *polygonData );
127
128  jmp_buf env;			/* place to jump to when memAllocs fail */
129
130  void *polygonData;		/* client data for current polygon */
131};
132
133void GLAPIENTRY __gl_noBeginData( GLenum type, void *polygonData );
134void GLAPIENTRY __gl_noEdgeFlagData( GLboolean boundaryEdge, void *polygonData );
135void GLAPIENTRY __gl_noVertexData( void *data, void *polygonData );
136void GLAPIENTRY __gl_noEndData( void *polygonData );
137void GLAPIENTRY __gl_noErrorData( GLenum errnum, void *polygonData );
138void GLAPIENTRY __gl_noCombineData( GLdouble coords[3], void *data[4],
139			 GLfloat weight[4], void **outData,
140			 void *polygonData );
141
142#define CALL_BEGIN_OR_BEGIN_DATA(a) \
143   if (tess->callBeginData != &__gl_noBeginData) \
144      (*tess->callBeginData)((a),tess->polygonData); \
145   else (*tess->callBegin)((a));
146
147#define CALL_VERTEX_OR_VERTEX_DATA(a) \
148   if (tess->callVertexData != &__gl_noVertexData) \
149      (*tess->callVertexData)((a),tess->polygonData); \
150   else (*tess->callVertex)((a));
151
152#define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
153   if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
154      (*tess->callEdgeFlagData)((a),tess->polygonData); \
155   else (*tess->callEdgeFlag)((a));
156
157#define CALL_END_OR_END_DATA() \
158   if (tess->callEndData != &__gl_noEndData) \
159      (*tess->callEndData)(tess->polygonData); \
160   else (*tess->callEnd)();
161
162#define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
163   if (tess->callCombineData != &__gl_noCombineData) \
164      (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
165   else (*tess->callCombine)((a),(b),(c),(d));
166
167#define CALL_ERROR_OR_ERROR_DATA(a) \
168   if (tess->callErrorData != &__gl_noErrorData) \
169      (*tess->callErrorData)((a),tess->polygonData); \
170   else (*tess->callError)((a));
171
172#endif
173