/*
=================
idRenderModelDecal::AddDepthFadedWinding
=================
*/
void idRenderModelDecal::AddDepthFadedWinding( const idWinding &w, const idMaterial *decalMaterial, const idPlane fadePlanes[2], float fadeDepth, int startTime ) {
idFixedWinding front, back;
front = w;
if( front.Split( &back, fadePlanes[0], 0.1f ) == SIDE_CROSS ) {
AddWinding( back, decalMaterial, fadePlanes, fadeDepth, startTime );
}
if( front.Split( &back, fadePlanes[1], 0.1f ) == SIDE_CROSS ) {
AddWinding( back, decalMaterial, fadePlanes, fadeDepth, startTime );
}
AddWinding( front, decalMaterial, fadePlanes, fadeDepth, startTime );
}
static int RemoveDegenerateFaces( TESStesselator *tess, TESSmesh *mesh )
/*
* Delete any degenerate faces with only two edges. WalkDirtyRegions()
* will catch almost all of these, but it won't catch degenerate faces
* produced by splice operations on already-processed edges.
* The two places this can happen are in FinishLeftRegions(), when
* we splice in a "temporary" edge produced by ConnectRightVertex(),
* and in CheckForLeftSplice(), where we splice already-processed
* edges to ensure that our dictionary invariants are not violated
* by numerical errors.
*
* In both these cases it is *very* dangerous to delete the offending
* edge at the time, since one of the routines further up the stack
* will sometimes be keeping a pointer to that edge.
*/
{
TESSface *f, *fNext;
TESShalfEdge *e;
/*LINTED*/
for( f = mesh->fHead.next; f != &mesh->fHead; f = fNext ) {
fNext = f->next;
e = f->anEdge;
assert( e->Lnext != e );
if( e->Lnext->Lnext == e ) {
/* A face with only two edges */
AddWinding( e->Onext, e );
if ( !tessMeshDelete( tess->mesh, e ) ) return 0;
}
}
return 1;
}
static void WalkDirtyRegions( TESStesselator *tess, ActiveRegion *regUp )
/*
* When the upper or lower edge of any region changes, the region is
* marked "dirty". This routine walks through all the dirty regions
* and makes sure that the dictionary invariants are satisfied
* (see the comments at the beginning of this file). Of course
* new dirty regions can be created as we make changes to restore
* the invariants.
*/
{
ActiveRegion *regLo = RegionBelow(regUp);
TESShalfEdge *eUp, *eLo;
for( ;; ) {
/* Find the lowest dirty region (we walk from the bottom up). */
while( regLo->dirty ) {
regUp = regLo;
regLo = RegionBelow(regLo);
}
if( ! regUp->dirty ) {
regLo = regUp;
regUp = RegionAbove( regUp );
if( regUp == NULL || ! regUp->dirty ) {
/* We've walked all the dirty regions */
return;
}
}
regUp->dirty = FALSE;
eUp = regUp->eUp;
eLo = regLo->eUp;
if( eUp->Dst != eLo->Dst ) {
/* Check that the edge ordering is obeyed at the Dst vertices. */
if( CheckForLeftSplice( tess, regUp )) {
/* If the upper or lower edge was marked fixUpperEdge, then
* we no longer need it (since these edges are needed only for
* vertices which otherwise have no right-going edges).
*/
if( regLo->fixUpperEdge ) {
DeleteRegion( tess, regLo );
if ( !tessMeshDelete( tess->mesh, eLo ) ) longjmp(tess->env,1);
regLo = RegionBelow( regUp );
eLo = regLo->eUp;
} else if( regUp->fixUpperEdge ) {
DeleteRegion( tess, regUp );
if ( !tessMeshDelete( tess->mesh, eUp ) ) longjmp(tess->env,1);
regUp = RegionAbove( regLo );
eUp = regUp->eUp;
}
}
}
if( eUp->Org != eLo->Org ) {
if( eUp->Dst != eLo->Dst
&& ! regUp->fixUpperEdge && ! regLo->fixUpperEdge
&& (eUp->Dst == tess->event || eLo->Dst == tess->event) )
{
/* When all else fails in CheckForIntersect(), it uses tess->event
* as the intersection location. To make this possible, it requires
* that tess->event lie between the upper and lower edges, and also
* that neither of these is marked fixUpperEdge (since in the worst
* case it might splice one of these edges into tess->event, and
* violate the invariant that fixable edges are the only right-going
* edge from their associated vertex).
*/
if( CheckForIntersect( tess, regUp )) {
/* WalkDirtyRegions() was called recursively; we're done */
return;
}
} else {
/* Even though we can't use CheckForIntersect(), the Org vertices
* may violate the dictionary edge ordering. Check and correct this.
*/
(void) CheckForRightSplice( tess, regUp );
}
}
if( eUp->Org == eLo->Org && eUp->Dst == eLo->Dst ) {
/* A degenerate loop consisting of only two edges -- delete it. */
AddWinding( eLo, eUp );
DeleteRegion( tess, regUp );
if ( !tessMeshDelete( tess->mesh, eUp ) ) longjmp(tess->env,1);
regUp = RegionAbove( regLo );
}
}
}
static void AddRightEdges( TESStesselator *tess, ActiveRegion *regUp,
TESShalfEdge *eFirst, TESShalfEdge *eLast, TESShalfEdge *eTopLeft,
int cleanUp )
/*
* Purpose: insert right-going edges into the edge dictionary, and update
* winding numbers and mesh connectivity appropriately. All right-going
* edges share a common origin vOrg. Edges are inserted CCW starting at
* eFirst; the last edge inserted is eLast->Oprev. If vOrg has any
* left-going edges already processed, then eTopLeft must be the edge
* such that an imaginary upward vertical segment from vOrg would be
* contained between eTopLeft->Oprev and eTopLeft; otherwise eTopLeft
* should be NULL.
*/
{
ActiveRegion *reg, *regPrev;
TESShalfEdge *e, *ePrev;
int firstTime = TRUE;
/* Insert the new right-going edges in the dictionary */
e = eFirst;
do {
assert( VertLeq( e->Org, e->Dst ));
AddRegionBelow( tess, regUp, e->Sym );
e = e->Onext;
} while ( e != eLast );
/* Walk *all* right-going edges from e->Org, in the dictionary order,
* updating the winding numbers of each region, and re-linking the mesh
* edges to match the dictionary ordering (if necessary).
*/
if( eTopLeft == NULL ) {
eTopLeft = RegionBelow( regUp )->eUp->Rprev;
}
regPrev = regUp;
ePrev = eTopLeft;
for( ;; ) {
reg = RegionBelow( regPrev );
e = reg->eUp->Sym;
if( e->Org != ePrev->Org ) break;
if( e->Onext != ePrev ) {
/* Unlink e from its current position, and relink below ePrev */
if ( !tessMeshSplice( tess->mesh, e->Oprev, e ) ) longjmp(tess->env,1);
if ( !tessMeshSplice( tess->mesh, ePrev->Oprev, e ) ) longjmp(tess->env,1);
}
/* Compute the winding number and "inside" flag for the new regions */
reg->windingNumber = regPrev->windingNumber - e->winding;
reg->inside = IsWindingInside( tess, reg->windingNumber );
/* Check for two outgoing edges with same slope -- process these
* before any intersection tests (see example in tessComputeInterior).
*/
regPrev->dirty = TRUE;
if( ! firstTime && CheckForRightSplice( tess, regPrev )) {
AddWinding( e, ePrev );
DeleteRegion( tess, regPrev );
if ( !tessMeshDelete( tess->mesh, ePrev ) ) longjmp(tess->env,1);
}
firstTime = FALSE;
regPrev = reg;
ePrev = e;
}
regPrev->dirty = TRUE;
assert( regPrev->windingNumber - e->winding == reg->windingNumber );
if( cleanUp ) {
/* Check for intersections between newly adjacent edges. */
WalkDirtyRegions( tess, regPrev );
}
}
