void REGALGLU_CALL
gluTessEndPolygon( GLUtesselator *tess )
{
GLUmesh *mesh;
if (setjmp(tess->env) != 0) {
/* come back here if out of memory */
CALL_ERROR_OR_ERROR_DATA( GLU_OUT_OF_MEMORY );
return;
}
RequireState( tess, T_IN_POLYGON );
tess->state = T_DORMANT;
if( tess->mesh == NULL ) {
if( ! tess->flagBoundary && tess->callMesh == &noMesh ) {
/* Try some special code to make the easy cases go quickly
* (eg. convex polygons). This code does NOT handle multiple contours,
* intersections, edge flags, and of course it does not generate
* an explicit mesh either.
*/
if( __gl_renderCache( tess )) {
tess->polygonData= NULL;
return;
}
}
if ( !EmptyCache( tess ) ) longjmp(tess->env,1); /* could've used a label*/
}
/* Determine the polygon normal and project vertices onto the plane
* of the polygon.
*/
__gl_projectPolygon( tess );
/* __gl_computeInterior( tess ) computes the planar arrangement specified
* by the given contours, and further subdivides this arrangement
* into regions. Each region is marked "inside" if it belongs
* to the polygon, according to the rule given by tess->windingRule.
* Each interior region is guaranteed be monotone.
*/
if ( !__gl_computeInterior( tess ) ) {
longjmp(tess->env,1); /* could've used a label */
}
mesh = tess->mesh;
if( ! tess->fatalError ) {
int rc = 1;
/* If the user wants only the boundary contours, we throw away all edges
* except those which separate the interior from the exterior.
* Otherwise we tessellate all the regions marked "inside".
*/
if( tess->boundaryOnly ) {
rc = __gl_meshSetWindingNumber( mesh, 1, TRUE );
} else {
rc = __gl_meshTessellateInterior( mesh );
}
if (rc == 0) longjmp(tess->env,1); /* could've used a label */
__gl_meshCheckMesh( mesh );
if( tess->callBegin != &noBegin || tess->callEnd != &noEnd
|| tess->callVertex != &noVertex || tess->callEdgeFlag != &noEdgeFlag
|| tess->callBeginData != &__gl_noBeginData
|| tess->callEndData != &__gl_noEndData
|| tess->callVertexData != &__gl_noVertexData
|| tess->callEdgeFlagData != &__gl_noEdgeFlagData )
{
if( tess->boundaryOnly ) {
__gl_renderBoundary( tess, mesh ); /* output boundary contours */
} else {
__gl_renderMesh( tess, mesh ); /* output strips and fans */
}
}
if( tess->callMesh != &noMesh ) {
/* Throw away the exterior faces, so that all faces are interior.
* This way the user doesn't have to check the "inside" flag,
* and we don't need to even reveal its existence. It also leaves
* the freedom for an implementation to not generate the exterior
* faces in the first place.
*/
__gl_meshDiscardExterior( mesh );
(*tess->callMesh)( mesh ); /* user wants the mesh itself */
tess->mesh = NULL;
tess->polygonData= NULL;
return;
}
}
__gl_meshDeleteMesh( mesh );
tess->polygonData= NULL;
tess->mesh = NULL;
}
int __gl_computeInterior( GLUtesselator *tess )
/*
* __gl_computeInterior( tess ) computes the planar arrangement specified
* by the given contours, and further subdivides this arrangement
* into regions. Each region is marked "inside" if it belongs
* to the polygon, according to the rule given by tess->windingRule.
* Each interior region is guaranteed be monotone.
*/
{
GLUvertex *v, *vNext;
tess->fatalError = FALSE;
/* Each vertex defines an event for our sweep line. Start by inserting
* all the vertices in a priority queue. Events are processed in
* lexicographic order, ie.
*
* e1 < e2 iff e1.x < e2.x || (e1.x == e2.x && e1.y < e2.y)
*/
RemoveDegenerateEdges( tess );
if ( !InitPriorityQ( tess ) ) return 0; /* if error */
InitEdgeDict( tess );
/* __gl_pqSortExtractMin */
while( (v = (GLUvertex *)pqExtractMin( tess->pq )) != NULL ) {
for( ;; ) {
vNext = (GLUvertex *)pqMinimum( tess->pq ); /* __gl_pqSortMinimum */
if( vNext == NULL || ! VertEq( vNext, v )) break;
/* Merge together all vertices at exactly the same location.
* This is more efficient than processing them one at a time,
* simplifies the code (see ConnectLeftDegenerate), and is also
* important for correct handling of certain degenerate cases.
* For example, suppose there are two identical edges A and B
* that belong to different contours (so without this code they would
* be processed by separate sweep events). Suppose another edge C
* crosses A and B from above. When A is processed, we split it
* at its intersection point with C. However this also splits C,
* so when we insert B we may compute a slightly different
* intersection point. This might leave two edges with a small
* gap between them. This kind of error is especially obvious
* when using boundary extraction (GLU_TESS_BOUNDARY_ONLY).
*/
vNext = (GLUvertex *)pqExtractMin( tess->pq ); /* __gl_pqSortExtractMin*/
SpliceMergeVertices( tess, v->anEdge, vNext->anEdge );
}
SweepEvent( tess, v );
}
/* Set tess->event for debugging purposes */
/* __GL_DICTLISTKEY */ /* __GL_DICTLISTMIN */
tess->event = ((ActiveRegion *) dictKey( dictMin( tess->dict )))->eUp->Org;
DebugEvent( tess );
DoneEdgeDict( tess );
DonePriorityQ( tess );
if ( !RemoveDegenerateFaces( tess->mesh ) ) return 0;
__gl_meshCheckMesh( tess->mesh );
return 1;
}
