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 "glues.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 */ 47 enum 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 54 typedef struct CachedVertex 55 { 56 double coords[3]; 57 void* data; 58 } CachedVertex; 59 60 struct GLUEStesselator 61 { 62 /*** state needed for collecting the input data ***/ 63 enum TessState state; /* what begin/end calls have we seen? */ 64 65 GLUEShalfEdge* lastEdge; /* lastEdge->Org is the most recent vertex */ 66 GLUESmesh* mesh; /* stores the input contours, and eventually 67 the tessellation itself */ 68 69 void (* callError)(GLenum errnum); 70 71 /*** state needed for projecting onto the sweep plane ***/ 72 double normal[3]; /* user-specified normal (if provided) */ 73 GLfloat sUnit[3]; /* unit vector in s-direction (debugging) */ 74 GLfloat tUnit[3]; /* unit vector in t-direction (debugging) */ 75 76 /*** state needed for the line sweep ***/ 77 GLfloat relTolerance; /* tolerance for merging features */ 78 GLenum windingRule; /* rule for determining polygon interior */ 79 GLboolean fatalError; /* fatal error: needed combine callback */ 80 81 Dict* dict; /* edge dictionary for sweep line */ 82 PriorityQ* pq; /* priority queue of vertex events */ 83 GLUESvertex* event; /* current sweep event being processed */ 84 85 void (* callCombine)(double coords[3], void* data[4], 86 GLfloat weight[4], void** outData); 87 88 /*** state needed for rendering callbacks (see render.c) ***/ 89 GLboolean flagBoundary; /* mark boundary edges (use EdgeFlag) */ 90 GLboolean boundaryOnly; /* Extract contours, not triangles */ 91 /* list of triangles which could not be rendered as strips or fans */ 92 GLUESface* lonelyTriList; 93 94 void (* callBegin)(GLenum type); 95 void (* callEdgeFlag)(GLboolean boundaryEdge); 96 void (* callVertex)(void* data); 97 void (* callEnd)(void); 98 void (* callMesh)(GLUESmesh* mesh); 99 100 /*** state needed to cache single-contour polygons for renderCache() */ 101 102 GLboolean emptyCache; /* empty cache on next vertex() call */ 103 int cacheCount; /* number of cached vertices */ 104 CachedVertex cache[TESS_MAX_CACHE]; /* the vertex data */ 105 106 /*** rendering callbacks that also pass polygon data ***/ 107 void (* callBeginData)(GLenum type, void* polygonData); 108 void (* callEdgeFlagData)(GLboolean boundaryEdge, void* polygonData); 109 void (* callVertexData)(void* data, void* polygonData); 110 void (* callEndData)(void* polygonData); 111 void (* callErrorData)(GLenum errnum, void *polygonData); 112 void (* callCombineData)(double coords[3], void* data[4], 113 GLfloat weight[4], void** outData, 114 void* polygonData); 115 116 jmp_buf env; /* place to jump to when memAllocs fail */ 117 118 void* polygonData; /* client data for current polygon */ 119 }; 120 121 void __gl_noBeginData(GLenum type, void* polygonData); 122 void __gl_noEdgeFlagData(GLboolean boundaryEdge, void* polygonData); 123 void __gl_noVertexData(void* data, void* polygonData); 124 void __gl_noEndData(void* polygonData); 125 void __gl_noErrorData(GLenum errnum, void* polygonData); 126 void __gl_noCombineData(double coords[3], void* data[4], 127 GLfloat weight[4], void** outData, 128 void* polygonData); 129 130 #define CALL_BEGIN_OR_BEGIN_DATA(a) \ 131 if (tess->callBeginData != &__gl_noBeginData) \ 132 (*tess->callBeginData)((a),tess->polygonData); \ 133 else (*tess->callBegin)((a)); 134 135 #define CALL_VERTEX_OR_VERTEX_DATA(a) \ 136 if (tess->callVertexData != &__gl_noVertexData) \ 137 (*tess->callVertexData)((a),tess->polygonData); \ 138 else (*tess->callVertex)((a)); 139 140 #define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \ 141 if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \ 142 (*tess->callEdgeFlagData)((a),tess->polygonData); \ 143 else (*tess->callEdgeFlag)((a)); 144 145 #define CALL_END_OR_END_DATA() \ 146 if (tess->callEndData != &__gl_noEndData) \ 147 (*tess->callEndData)(tess->polygonData); \ 148 else (*tess->callEnd)(); 149 150 #define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \ 151 if (tess->callCombineData != &__gl_noCombineData) \ 152 (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \ 153 else (*tess->callCombine)((a),(b),(c),(d)); 154 155 #define CALL_ERROR_OR_ERROR_DATA(a) \ 156 if (tess->callErrorData != &__gl_noErrorData) \ 157 (*tess->callErrorData)((a),tess->polygonData); \ 158 else (*tess->callError)((a)); 159 160 #endif /* __tess_h_ */ 161