Function rcBuildPolyMesh

Source/ThirdParty/recastnavigation/RecastMesh.cpp:989–1305

@par @note If the mesh data is to be used to construct a Detour navigation mesh, then the upper limit must be retricted to <= #DT_VERTS_PER_POLYGON. @see rcAllocPolyMesh, rcContourSet, rcPolyMesh, rcConfig

///
/// @see rcAllocPolyMesh, rcContourSet, rcPolyMesh, rcConfig
bool rcBuildPolyMesh(rcContext* ctx, const rcContourSet& cset, const int nvp, rcPolyMesh& mesh)
{
	rcAssert(ctx);
	
	rcScopedTimer timer(ctx, RC_TIMER_BUILD_POLYMESH);

	rcVcopy(mesh.bmin, cset.bmin);
	rcVcopy(mesh.bmax, cset.bmax);
	mesh.cs = cset.cs;
	mesh.ch = cset.ch;
	mesh.borderSize = cset.borderSize;
	mesh.maxEdgeError = cset.maxError;
	
	int maxVertices = 0;
	int maxTris = 0;
	int maxVertsPerCont = 0;
	for (int i = 0; i < cset.nconts; ++i)
	{
		// Skip null contours.
		if (cset.conts[i].nverts < 3) continue;
		maxVertices += cset.conts[i].nverts;
		maxTris += cset.conts[i].nverts - 2;
		maxVertsPerCont = rcMax(maxVertsPerCont, cset.conts[i].nverts);
	}
	
	if (maxVertices >= 0xfffe)
	{
		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Too many vertices %d.", maxVertices);
		return false;
	}
		
	rcScopedDelete<unsigned char> vflags((unsigned char*)rcAlloc(sizeof(unsigned char)*maxVertices, RC_ALLOC_TEMP));
	if (!vflags)
	{
		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'vflags' (%d).", maxVertices);
		return false;
	}
	memset(vflags, 0, maxVertices);
	
	mesh.verts = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxVertices*3, RC_ALLOC_PERM);
	if (!mesh.verts)
	{
		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'mesh.verts' (%d).", maxVertices);
		return false;
	}
	mesh.polys = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxTris*nvp*2, RC_ALLOC_PERM);
	if (!mesh.polys)
	{
		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'mesh.polys' (%d).", maxTris*nvp*2);
		return false;
	}
	mesh.regs = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxTris, RC_ALLOC_PERM);
	if (!mesh.regs)
	{
		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'mesh.regs' (%d).", maxTris);
		return false;
	}
	mesh.areas = (unsigned char*)rcAlloc(sizeof(unsigned char)*maxTris, RC_ALLOC_PERM);