public static bool buildMeshAdjacency(ushort[] polys, int npolys,
int nverts, int vertsPerPoly)
{
// Based on code by Eric Lengyel from:
// http://www.terathon.com/code/edges.php
int maxEdgeCount = npolys * vertsPerPoly;
ushort[] firstEdge = new ushort[nverts + maxEdgeCount];//(ushort*)rcAlloc(sizeof(ushort)*(nverts + maxEdgeCount), RC_ALLOC_TEMP);
if (firstEdge == null)
return false;
//ushort* nextEdge = firstEdge + nverts;
int nextEdgeIndex = nverts;
int edgeCount = 0;
//rcEdge* edges = (rcEdge*)rcAlloc(sizeof(rcEdge)*maxEdgeCount, RC_ALLOC_TEMP);
rcEdge[] edges = new rcEdge[maxEdgeCount];
rccsArrayItemsCreate(edges);
if (edges == null) {
//rcFree(firstEdge);
firstEdge = null;
return false;
}
for (int i = 0; i < nverts; i++) {
firstEdge[i] = RC_MESH_NULL_IDX;
}
for (int i = 0; i < npolys; ++i) {
int tIndex = i * vertsPerPoly * 2;
//ushort* t = &polys[i*vertsPerPoly*2];
for (int j = 0; j < vertsPerPoly; ++j) {
if (polys[tIndex + j] == RC_MESH_NULL_IDX) break;
ushort v0 = polys[tIndex + j];
ushort v1 = (j + 1 >= vertsPerPoly || polys[tIndex + j + 1] == RC_MESH_NULL_IDX) ? polys[tIndex + 0] : polys[tIndex + j + 1];
if (v0 < v1) {
rcEdge edge = edges[edgeCount];
edge.vert[0] = v0;
edge.vert[1] = v1;
edge.poly[0] = (ushort)i;
edge.polyEdge[0] = (ushort)j;
edge.poly[1] = (ushort)i;
edge.polyEdge[1] = 0;
// Insert edge
firstEdge[nextEdgeIndex + edgeCount] = firstEdge[v0];
firstEdge[v0] = (ushort)edgeCount;
edgeCount++;
}
}
}
for (int i = 0; i < npolys; ++i) {
//ushort* t = &polys[i*vertsPerPoly*2];
int tIndex = i * vertsPerPoly * 2;
for (int j = 0; j < vertsPerPoly; ++j) {
if (polys[tIndex + j] == RC_MESH_NULL_IDX) break;
ushort v0 = polys[tIndex + j];
ushort v1 = (j + 1 >= vertsPerPoly || polys[tIndex + j + 1] == RC_MESH_NULL_IDX) ? polys[tIndex + 0] : polys[tIndex + j + 1];
if (v0 > v1) {
for (ushort e = firstEdge[v1]; e != RC_MESH_NULL_IDX; e = firstEdge[nextEdgeIndex + e]) {
rcEdge edge = edges[e];
if (edge.vert[1] == v0 && edge.poly[0] == edge.poly[1]) {
edge.poly[1] = (ushort)i;
edge.polyEdge[1] = (ushort)j;
break;
}
}
}
}
}
// Store adjacency
for (int i = 0; i < edgeCount; ++i) {
rcEdge e = edges[i];
if (e.poly[0] != e.poly[1]) {
//ushort* p0 = &polys[e.poly[0]*vertsPerPoly*2];
//ushort* p1 = &polys[e.poly[1]*vertsPerPoly*2];
//p0[vertsPerPoly + e.polyEdge[0]] = e.poly[1];
//p1[vertsPerPoly + e.polyEdge[1]] = e.poly[0];
polys[e.poly[0] * vertsPerPoly * 2 + vertsPerPoly + e.polyEdge[0]] = e.poly[1];
polys[e.poly[1] * vertsPerPoly * 2 + vertsPerPoly + e.polyEdge[1]] = e.poly[0];
}
}
//rcFree(firstEdge);
//rcFree(edges);
return true;
}
static bool BuildAdjacency(int nverts, int npolys, ref ushort[] tris)
{
int maxEdgeCount = npolys * nvp;
ushort[] firstEdge = new ushort[nverts + maxEdgeCount];
int edgeCount = 0;
rcEdge[] edges = new rcEdge[maxEdgeCount];
for (int i = 0; i < maxEdgeCount; i++)
{
edges[i] = new rcEdge();
edges[i].vert = new ushort[2] {
0, 0
};
edges[i].polyEdge = new ushort[2] {
0, 0
};
edges[i].poly = new ushort[2] {
0, 0
};
}
for (int i = 0; i < nverts; i++)
{
firstEdge[i] = RC_MESH_NULL_IDX;
}
const int un = nvp * 2;
for (int i = 0; i < npolys; ++i)
{
for (int j = 0; j < nvp; ++j)
{
if (tris[i * un + j] == RC_MESH_NULL_IDX)
{
break;
}
ushort v0 = tris[i * un + j];
ushort v1 = ((j + 1 >= nvp) || (tris[i * un + j + 1] == RC_MESH_NULL_IDX)) ? tris[i * un] : tris[i * un + j + 1];
if (v0 < v1)
{
rcEdge edge = edges[edgeCount];
edge.vert[0] = v0;
edge.vert[1] = v1;
edge.poly[0] = (ushort)i;
edge.polyEdge[0] = (ushort)j;
edge.poly[1] = (ushort)i;
edge.polyEdge[1] = 0;
// Insert edge
firstEdge[nverts + edgeCount] = firstEdge[v0];
firstEdge[v0] = (ushort)edgeCount;
edgeCount++;
}
}
}
for (int i = 0; i < npolys; ++i)
{
for (int j = 0; j < nvp; ++j)
{
if (tris[i * un + j] == RC_MESH_NULL_IDX)
{
break;
}
ushort v0 = tris[i * un + j];
ushort v1 = ((j + 1 >= nvp) || (tris[i * un + j + 1] == RC_MESH_NULL_IDX)) ? tris[i * un] : tris[i * un + j + 1];
if (v0 > v1)
{
for (ushort e = firstEdge[v1]; e != RC_MESH_NULL_IDX; e = firstEdge[nverts + e])
{
rcEdge edge = edges[e];
if (edge.vert[1] == v0 && edge.poly[0] == edge.poly[1])
{
edge.poly[1] = (ushort)i;
edge.polyEdge[1] = (ushort)j;
break;
}
}
}
}
}
// Store adjacency
for (int i = 0; i < edgeCount; ++i)
{
rcEdge e = edges[i];
if (e.poly[0] != e.poly[1])
{
tris[e.poly[0] * un + nvp + e.polyEdge[0]] = e.poly[1];
tris[e.poly[1] * un + nvp + e.polyEdge[1]] = e.poly[0];
}
}
return(true);
}
