Function dtBuildTileCachePolyMesh

3rdparty/recast/DetourTileCacheBuilder.cpp:1748–1955

dtStatus dtBuildTileCachePolyMesh(dtTileCacheAlloc* alloc,
								  dtTileCacheContourSet& lcset,
								  dtTileCachePolyMesh& mesh)
{
	dtAssert(alloc);
	
	int maxVertices = 0;
	int maxTris = 0;
	int maxVertsPerCont = 0;
	for (int i = 0; i < lcset.nconts; ++i)
	{
		// Skip null contours.
		if (lcset.conts[i].nverts < 3) continue;
		maxVertices += lcset.conts[i].nverts;
		maxTris += lcset.conts[i].nverts - 2;
		maxVertsPerCont = dtMax(maxVertsPerCont, lcset.conts[i].nverts);
	}

	// TODO: warn about too many vertices?
	
	mesh.nvp = MAX_VERTS_PER_POLY;
	
	dtFixedArray<unsigned char> vflags(alloc, maxVertices);
	if (!vflags)
		return DT_FAILURE | DT_OUT_OF_MEMORY;
	memset(vflags, 0, maxVertices);
	
	mesh.verts = (unsigned short*)alloc->alloc(sizeof(unsigned short)*maxVertices*3);
	if (!mesh.verts)
		return DT_FAILURE | DT_OUT_OF_MEMORY;
	
	mesh.polys = (unsigned short*)alloc->alloc(sizeof(unsigned short)*maxTris*MAX_VERTS_PER_POLY*2);
	if (!mesh.polys)
		return DT_FAILURE | DT_OUT_OF_MEMORY;

	mesh.areas = (unsigned char*)alloc->alloc(sizeof(unsigned char)*maxTris);
	if (!mesh.areas)
		return DT_FAILURE | DT_OUT_OF_MEMORY;

	mesh.flags = (unsigned short*)alloc->alloc(sizeof(unsigned short)*maxTris);
	if (!mesh.flags)
		return DT_FAILURE | DT_OUT_OF_MEMORY;

	// Just allocate and clean the mesh flags array. The user is resposible for filling it.
	memset(mesh.flags, 0, sizeof(unsigned short) * maxTris);
		
	mesh.nverts = 0;
	mesh.npolys = 0;
	
	memset(mesh.verts, 0, sizeof(unsigned short)*maxVertices*3);
	memset(mesh.polys, 0xff, sizeof(unsigned short)*maxTris*MAX_VERTS_PER_POLY*2);
	memset(mesh.areas, 0, sizeof(unsigned char)*maxTris);
	
	unsigned short firstVert[VERTEX_BUCKET_COUNT2];
	for (int i = 0; i < VERTEX_BUCKET_COUNT2; ++i)
		firstVert[i] = DT_TILECACHE_NULL_IDX;
	
	dtFixedArray<unsigned short> nextVert(alloc, maxVertices);