2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
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28 * Silicon Graphics, Inc.
31 ** Author: Eric Veach, July 1994.
42 typedef struct Dict Dict
;
46 /* Since we support deletion the data structure is a little more
47 * complicated than an ordinary heap. "nodes" is the heap itself;
48 * active nodes are stored in the range 1..pq->size. When the
49 * heap exceeds its allocated size (pq->max), its size doubles.
50 * The children of node i are nodes 2i and 2i+1.
52 * Each node stores an index into an array "handles". Each handle
53 * stores a key, plus a pointer back to the node which currently
54 * represents that key (ie. nodes[handles[i].node].handle == i).
58 typedef long PQhandle
;
59 typedef struct PriorityQSort PriorityQSort
;
61 PriorityQSort
*__gl_pqSortNewPriorityQ( int (*leq
)(PQkey key1
, PQkey key2
) );
62 void __gl_pqSortDeletePriorityQ( PriorityQSort
*pq
);
64 int __gl_pqSortInit( PriorityQSort
*pq
);
65 PQhandle
__gl_pqSortInsert( PriorityQSort
*pq
, PQkey key
);
66 PQkey
__gl_pqSortExtractMin( PriorityQSort
*pq
);
67 void __gl_pqSortDelete( PriorityQSort
*pq
, PQhandle handle
);
69 PQkey
__gl_pqSortMinimum( PriorityQSort
*pq
);
70 int __gl_pqSortIsEmpty( PriorityQSort
*pq
);
73 #define VertEq(u,v) ((u)->s == (v)->s && (u)->t == (v)->t)
74 #define VertLeq(u,v) (((u)->s < (v)->s) || \
75 ((u)->s == (v)->s && (u)->t <= (v)->t))
76 #define EdgeEval(u,v,w) __gl_edgeEval(u,v,w)
77 #define EdgeSign(u,v,w) __gl_edgeSign(u,v,w)
79 /* Versions of VertLeq, EdgeSign, EdgeEval with s and t transposed. */
81 #define TransLeq(u,v) (((u)->t < (v)->t) || \
82 ((u)->t == (v)->t && (u)->s <= (v)->s))
83 #define TransEval(u,v,w) __gl_transEval(u,v,w)
84 #define TransSign(u,v,w) __gl_transSign(u,v,w)
87 #define EdgeGoesLeft(e) VertLeq( (e)->Dst, (e)->Org )
88 #define EdgeGoesRight(e) VertLeq( (e)->Org, (e)->Dst )
91 #define ABS(x) ((x) < 0 ? -(x) : (x))
92 #define VertL1dist(u,v) (ABS(u->s - v->s) + ABS(u->t - v->t))
94 #define VertCCW(u,v,w) __gl_vertCCW(u,v,w)
96 int __gl_vertLeq( GLUvertex
*u
, GLUvertex
*v
);
97 GLdouble
__gl_edgeEval( GLUvertex
*u
, GLUvertex
*v
, GLUvertex
*w
);
98 GLdouble
__gl_edgeSign( GLUvertex
*u
, GLUvertex
*v
, GLUvertex
*w
);
99 GLdouble
__gl_transEval( GLUvertex
*u
, GLUvertex
*v
, GLUvertex
*w
);
100 GLdouble
__gl_transSign( GLUvertex
*u
, GLUvertex
*v
, GLUvertex
*w
);
101 int __gl_vertCCW( GLUvertex
*u
, GLUvertex
*v
, GLUvertex
*w
);
102 void __gl_edgeIntersect( GLUvertex
*o1
, GLUvertex
*d1
,
103 GLUvertex
*o2
, GLUvertex
*d2
,
106 /* The begin/end calls must be properly nested. We keep track of
107 * the current state to enforce the ordering.
109 enum TessState
{ T_DORMANT
, T_IN_POLYGON
, T_IN_CONTOUR
};
111 /* We cache vertex data for single-contour polygons so that we can
112 * try a quick-and-dirty decomposition first.
114 #define TESS_MAX_CACHE 100
116 typedef struct CachedVertex
{
121 struct GLUtesselator
{
123 /*** state needed for collecting the input data ***/
125 enum TessState state
; /* what begin/end calls have we seen? */
127 GLUhalfEdge
*lastEdge
; /* lastEdge->Org is the most recent vertex */
128 GLUmesh
*mesh
; /* stores the input contours, and eventually
129 the tessellation itself */
131 void (GLAPIENTRY
*callError
)( GLenum errnum
);
133 /*** state needed for projecting onto the sweep plane ***/
135 GLdouble normal
[3]; /* user-specified normal (if provided) */
136 GLdouble sUnit
[3]; /* unit vector in s-direction (debugging) */
137 GLdouble tUnit
[3]; /* unit vector in t-direction (debugging) */
139 /*** state needed for the line sweep ***/
141 GLdouble relTolerance
; /* tolerance for merging features */
142 GLenum windingRule
; /* rule for determining polygon interior */
143 GLboolean fatalError
; /* fatal error: needed combine callback */
145 Dict
*dict
; /* edge dictionary for sweep line */
146 PriorityQSort
*pq
; /* priority queue of vertex events */
147 GLUvertex
*event
; /* current sweep event being processed */
149 void (GLAPIENTRY
*callCombine
)( GLdouble coords
[3], void *data
[4],
150 GLfloat weight
[4], void **outData
);
152 /*** state needed for rendering callbacks (see render.c) ***/
154 GLboolean flagBoundary
; /* mark boundary edges (use EdgeFlag) */
155 GLboolean boundaryOnly
; /* Extract contours, not triangles */
156 GLUface
*lonelyTriList
;
157 /* list of triangles which could not be rendered as strips or fans */
159 void (GLAPIENTRY
*callBegin
)( GLenum type
);
160 void (GLAPIENTRY
*callEdgeFlag
)( GLboolean boundaryEdge
);
161 void (GLAPIENTRY
*callVertex
)( void *data
);
162 void (GLAPIENTRY
*callEnd
)( void );
163 void (GLAPIENTRY
*callMesh
)( GLUmesh
*mesh
);
166 /*** state needed to cache single-contour polygons for renderCache() */
168 GLboolean emptyCache
; /* empty cache on next vertex() call */
169 int cacheCount
; /* number of cached vertices */
170 CachedVertex cache
[TESS_MAX_CACHE
]; /* the vertex data */
172 /*** rendering callbacks that also pass polygon data ***/
173 void (GLAPIENTRY
*callBeginData
)( GLenum type
, void *polygonData
);
174 void (GLAPIENTRY
*callEdgeFlagData
)( GLboolean boundaryEdge
,
176 void (GLAPIENTRY
*callVertexData
)( void *data
, void *polygonData
);
177 void (GLAPIENTRY
*callEndData
)( void *polygonData
);
178 void (GLAPIENTRY
*callErrorData
)( GLenum errnum
, void *polygonData
);
179 void (GLAPIENTRY
*callCombineData
)( GLdouble coords
[3], void *data
[4],
180 GLfloat weight
[4], void **outData
,
183 jmp_buf env
; /* place to jump to when memAllocs fail */
185 void *polygonData
; /* client data for current polygon */
188 void GLAPIENTRY
__gl_noBeginData( GLenum type
, void *polygonData
);
189 void GLAPIENTRY
__gl_noEdgeFlagData( GLboolean boundaryEdge
, void *polygonData
);
190 void GLAPIENTRY
__gl_noVertexData( void *data
, void *polygonData
);
191 void GLAPIENTRY
__gl_noEndData( void *polygonData
);
192 void GLAPIENTRY
__gl_noErrorData( GLenum errnum
, void *polygonData
);
193 void GLAPIENTRY
__gl_noCombineData( GLdouble coords
[3], void *data
[4],
194 GLfloat weight
[4], void **outData
,
197 #define CALL_BEGIN_OR_BEGIN_DATA(a) \
198 if (tess->callBeginData != &__gl_noBeginData) \
199 (*tess->callBeginData)((a),tess->polygonData); \
200 else (*tess->callBegin)((a));
202 #define CALL_VERTEX_OR_VERTEX_DATA(a) \
203 if (tess->callVertexData != &__gl_noVertexData) \
204 (*tess->callVertexData)((a),tess->polygonData); \
205 else (*tess->callVertex)((a));
207 #define CALL_EDGE_FLAG_OR_EDGE_FLAG_DATA(a) \
208 if (tess->callEdgeFlagData != &__gl_noEdgeFlagData) \
209 (*tess->callEdgeFlagData)((a),tess->polygonData); \
210 else (*tess->callEdgeFlag)((a));
212 #define CALL_END_OR_END_DATA() \
213 if (tess->callEndData != &__gl_noEndData) \
214 (*tess->callEndData)(tess->polygonData); \
215 else (*tess->callEnd)();
217 #define CALL_COMBINE_OR_COMBINE_DATA(a,b,c,d) \
218 if (tess->callCombineData != &__gl_noCombineData) \
219 (*tess->callCombineData)((a),(b),(c),(d),tess->polygonData); \
220 else (*tess->callCombine)((a),(b),(c),(d));
222 #define CALL_ERROR_OR_ERROR_DATA(a) \
223 if (tess->callErrorData != &__gl_noErrorData) \
224 (*tess->callErrorData)((a),tess->polygonData); \
225 else (*tess->callError)((a));
227 void __gl_renderMesh( GLUtesselator
*tess
, GLUmesh
*mesh
);
228 void __gl_renderBoundary( GLUtesselator
*tess
, GLUmesh
*mesh
);
230 GLboolean
__gl_renderCache( GLUtesselator
*tess
);
232 /* __gl_computeInterior( tess ) computes the planar arrangement specified
233 * by the given contours, and further subdivides this arrangement
234 * into regions. Each region is marked "inside" if it belongs
235 * to the polygon, according to the rule given by tess->windingRule.
236 * Each interior region is guaranteed be monotone.
238 int __gl_computeInterior( GLUtesselator
*tess
);