| public IsWindingInside ( int numCrossings ) : bool | ||
| numCrossings | int | |
| Результат | bool | |
static void ComputeWinding(Tesselator tess, ActiveRegion reg)
{
reg.windingNumber = reg.RegionAbove().windingNumber + reg.upperHalfEdge.winding;
reg.inside = tess.IsWindingInside(reg.windingNumber);
}
static void AddRightEdges(Tesselator tess, ActiveRegion regUp,
HalfEdge eFirst, HalfEdge eLast, HalfEdge eTopLeft,
bool 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;
HalfEdge e, ePrev;
bool firstTime = true;
/* Insert the new right-going edges in the dictionary */
e = eFirst;
do
{
if (!e.originVertex.VertLeq(e.directionVertex))
{
throw new Exception();
}
AddRegionBelow(tess, regUp, e.otherHalfOfThisEdge);
e = e.nextEdgeCCWAroundOrigin;
} 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).upperHalfEdge.Rprev;
}
regPrev = regUp;
ePrev = eTopLeft;
for (;;)
{
reg = RegionBelow(regPrev);
e = reg.upperHalfEdge.otherHalfOfThisEdge;
if (e.originVertex != ePrev.originVertex) break;
if (e.nextEdgeCCWAroundOrigin != ePrev)
{
/* Unlink e from its current position, and relink below ePrev */
Mesh.meshSplice(e.Oprev, e);
Mesh.meshSplice(ePrev.Oprev, e);
}
/* Compute the winding number and "inside" flag for the new regions */
reg.windingNumber = regPrev.windingNumber - e.winding;
reg.inside = tess.IsWindingInside(reg.windingNumber);
/* Check for two outgoing edges with same slope -- process these
* before any intersection tests (see example in __gl_computeInterior).
*/
regPrev.dirty = true;
if (!firstTime && CheckForRightSplice(tess, regPrev))
{
AddWinding(e, ePrev);
DeleteRegion(regPrev);
Mesh.DeleteHalfEdge(ePrev);
}
firstTime = false;
regPrev = reg;
ePrev = e;
}
regPrev.dirty = true;
if (regPrev.windingNumber - e.winding != reg.windingNumber)
{
throw new Exception();
}
if (cleanUp)
{
/* Check for intersections between newly adjacent edges. */
WalkDirtyRegions(tess, regPrev);
}
}
/*
* 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.
*/
static void AddRightEdges(Tesselator tess, ActiveRegion regUp,
HalfEdge eFirst, HalfEdge eLast, HalfEdge eTopLeft,
bool cleanUp)
{
ActiveRegion reg, regPrev;
HalfEdge e, ePrev;
bool firstTime = true;
/* Insert the new right-going edges in the dictionary */
e = eFirst;
do
{
if (!e.originVertex.VertLeq(e.directionVertex))
{
throw new Exception();
}
AddRegionBelow(tess, regUp, e.otherHalfOfThisEdge);
e = e.nextEdgeCCWAroundOrigin;
} 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).upperHalfEdge.Rprev;
}
regPrev = regUp;
ePrev = eTopLeft;
for (; ; )
{
reg = RegionBelow(regPrev);
e = reg.upperHalfEdge.otherHalfOfThisEdge;
if (e.originVertex != ePrev.originVertex) break;
if (e.nextEdgeCCWAroundOrigin != ePrev)
{
/* Unlink e from its current position, and relink below ePrev */
Mesh.meshSplice(e.Oprev, e);
Mesh.meshSplice(ePrev.Oprev, e);
}
/* Compute the winding number and "inside" flag for the new regions */
reg.windingNumber = regPrev.windingNumber - e.winding;
reg.inside = tess.IsWindingInside(reg.windingNumber);
/* Check for two outgoing edges with same slope -- process these
* before any intersection tests (see example in __gl_computeInterior).
*/
regPrev.dirty = true;
if (!firstTime && CheckForRightSplice(tess, regPrev))
{
AddWinding(e, ePrev);
DeleteRegion(regPrev);
Mesh.DeleteHalfEdge(ePrev);
}
firstTime = false;
regPrev = reg;
ePrev = e;
}
regPrev.dirty = true;
if (regPrev.windingNumber - e.winding != reg.windingNumber)
{
throw new Exception();
}
if (cleanUp)
{
/* Check for intersections between newly adjacent edges. */
WalkDirtyRegions(tess, regPrev);
}
}
