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31 ** Author: Eric Veach, July 1994.
42 #include "priorityq.h"
44 /* The begin/end calls must be properly nested. We keep track of
45 * the current state to enforce the ordering.
47 enum TessState
{ T_DORMANT
, T_IN_POLYGON
, T_IN_CONTOUR
};
49 /* We cache vertex data for single-contour polygons so that we can
50 * try a quick-and-dirty decomposition first.
52 #define TESS_MAX_CACHE 100
54 typedef struct CachedVertex
{
59 struct GLUtesselator
{
61 /*** state needed for collecting the input data ***/
63 enum TessState state
; /* what begin/end calls have we seen? */
65 GLUhalfEdge
*lastEdge
; /* lastEdge->Org is the most recent vertex */
66 GLUmesh
*mesh
; /* stores the input contours, and eventually
67 the tessellation itself */
69 void (GLAPIENTRY
*callError
)( GLenum errnum
);
71 /*** state needed for projecting onto the sweep plane ***/
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) */
77 /*** state needed for the line sweep ***/
79 GLdouble relTolerance
; /* tolerance for merging features */
80 GLenum windingRule
; /* rule for determining polygon interior */
81 GLboolean fatalError
; /* fatal error: needed combine callback */
83 Dict
*dict
; /* edge dictionary for sweep line */
84 PriorityQ
*pq
; /* priority queue of vertex events */
85 GLUvertex
*event
; /* current sweep event being processed */
87 void (GLAPIENTRY
*callCombine
)( GLdouble coords
[3], void *data
[4],
88 GLfloat weight
[4], void **outData
);
90 /*** state needed for rendering callbacks (see render.c) ***/
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 */
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
);
104 /*** state needed to cache single-contour polygons for renderCache() */
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 */
110 /*** rendering callbacks that also pass polygon data ***/
111 void (GLAPIENTRY
*callBeginData
)( GLenum type
, void *polygonData
);
112 void (GLAPIENTRY
*callEdgeFlagData
)( GLboolean boundaryEdge
,
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
,
121 jmp_buf env
; /* place to jump to when memAllocs fail */
123 void *polygonData
; /* client data for current polygon */
126 void GLAPIENTRY
__gl_noBeginData( GLenum type
, void *polygonData
);
127 void GLAPIENTRY
__gl_noEdgeFlagData( GLboolean boundaryEdge
, void *polygonData
);
128 void GLAPIENTRY
__gl_noVertexData( void *data
, void *polygonData
);
129 void GLAPIENTRY
__gl_noEndData( void *polygonData
);
130 void GLAPIENTRY
__gl_noErrorData( GLenum errnum
, void *polygonData
);
131 void GLAPIENTRY
__gl_noCombineData( GLdouble coords
[3], void *data
[4],
132 GLfloat weight
[4], void **outData
,
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));
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));
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));
150 #define CALL_END_OR_END_DATA() \
151 if (tess->callEndData != &__gl_noEndData) \
152 (*tess->callEndData)(tess->polygonData); \
153 else (*tess->callEnd)();
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));
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));