public int GetChunksOverlappingRect(float[] bmin, float[] bmax, ref int[] ids, int maxIds)
{
int i = 0;
int n = 0;
while (i < NNodes)
{
ChunkyTriMeshNode node = Nodes[i];
bool overlap = CheckOverlapRect(bmin, bmax, node.bmin, node.bmax);
bool isLeafNode = node.i >= 0;
if (isLeafNode && overlap)
{
if (n < maxIds)
{
ids[n] = i;
n++;
}
}
if (overlap || isLeafNode)
{
i++;
}
else
{
int escapeIndex = -node.i;
i += escapeIndex;
}
}
return(n);
}
private void CalcExtends(BoundsItem[] items, int nitems, int imin, int imax, ref ChunkyTriMeshNode node)
{
node.bmin[0] = items[imin].bmin[0];
node.bmin[1] = items[imin].bmin[1];
node.bmax[0] = items[imin].bmax[0];
node.bmax[1] = items[imin].bmax[1];
for (int i = imin + 1; i < imax; i++)
{
BoundsItem it = items[i];
if (it.bmin[0] < node.bmin[0])
{
node.bmin[0] = it.bmin[0];
}
if (it.bmin[1] < node.bmin[1])
{
node.bmin[1] = it.bmin[1];
}
if (it.bmax[0] > node.bmax[0])
{
node.bmax[0] = it.bmax[0];
}
if (it.bmax[1] > node.bmax[1])
{
node.bmax[1] = it.bmax[1];
}
}
}
public ChunkyTriMesh(RecastVertex[] verts, int[] tris, int ntris, int trisPerChunk)
{
int nchunks = (ntris + trisPerChunk - 1) / trisPerChunk;
Nodes = new ChunkyTriMeshNode[nchunks * 4];
Tris = new int[ntris * 3];
NTris = ntris;
BoundsItem[] items = new BoundsItem[ntris];
for (int i = 0; i < ntris; i++)
{
int t = i * 3;
items[i] = new BoundsItem();
BoundsItem it = items[i];
it.i = i;
it.bmin[0] = it.bmax[0] = verts[tris[t]].X;
it.bmin[1] = it.bmax[1] = verts[tris[t]].Z;
for (int j = 1; j < 3; j++)
{
int v = tris[t + j];
if (verts[v].X < it.bmin[0])
{
it.bmin[0] = verts[v].X;
}
if (verts[v].Z < it.bmin[1])
{
it.bmin[1] = verts[v].Z;
}
if (verts[v].X > it.bmax[0])
{
it.bmax[0] = verts[v].X;
}
if (verts[v].Z > it.bmax[1])
{
it.bmax[1] = verts[v].Z;
}
}
}
int curTri = 0;
int curNode = 0;
Subdivide(ref items, ntris, 0, ntris, trisPerChunk, ref curNode, nchunks * 4, ref curTri, tris);
NNodes = curNode;
MaxTrisPerChunk = 0;
for (int i = 0; i < NNodes; i++)
{
bool isLeaf = Nodes[i].i >= 0;
if (!isLeaf)
{
continue;
}
if (Nodes[i].n > MaxTrisPerChunk)
{
MaxTrisPerChunk = Nodes[i].n;
}
}
}
private void Subdivide(ref BoundsItem[] items, int nitems, int imin, int imax, int trisPerChunk, ref int curNode, int maxNodes, ref int curTri, int[] tris)
{
int inum = imax - imin;
int icur = curNode;
if (curNode > maxNodes)
{
return;
}
var node = Nodes[curNode];
if (Nodes[curNode] == null)
{
node = new ChunkyTriMeshNode();
Nodes[curNode] = node;
}
curNode++;
if (inum <= trisPerChunk)
{
CalcExtends(items, nitems, imin, imax, ref node);
node.i = curTri;
node.n = inum;
for (int i = imin; i < imax; i++)
{
int src = items[i].i * 3;
int dst = curTri * 3;
curTri++;
Tris[dst + 0] = tris[src + 0];
Tris[dst + 1] = tris[src + 1];
Tris[dst + 2] = tris[src + 2];
}
}
else
{
CalcExtends(items, nitems, imin, imax, ref node);
int axis = LongestAxis(node.bmax[0] - node.bmin[0], node.bmax[1] - node.bmin[1]);
if (axis == 0)
{
// sort along x-axis
Array.Sort(items, imin, inum, new CompareItemX());
}
else if (axis == 1)
{
// sort along y-axis
Array.Sort(items, imin, inum, new CompareItemY());
}
int isplit = imin + inum / 2;
Subdivide(ref items, nitems, imin, isplit, trisPerChunk, ref curNode, maxNodes, ref curTri, tris);
Subdivide(ref items, nitems, isplit, imax, trisPerChunk, ref curNode, maxNodes, ref curTri, tris);
int iescape = curNode - icur;
node.i = -iescape;
}
}