private void calcExtends(BoundsItem[] items, int imin, int imax, float[] bmin, float[] bmax)
{
bmin[0] = items[imin].bmin[0];
bmin[1] = items[imin].bmin[1];
bmax[0] = items[imin].bmax[0];
bmax[1] = items[imin].bmax[1];
for (int i = imin + 1; i < imax; ++i)
{
BoundsItem it = items[i];
if (it.bmin[0] < bmin[0])
{
bmin[0] = it.bmin[0];
}
if (it.bmin[1] < bmin[1])
{
bmin[1] = it.bmin[1];
}
if (it.bmax[0] > bmax[0])
{
bmax[0] = it.bmax[0];
}
if (it.bmax[1] > bmax[1])
{
bmax[1] = it.bmax[1];
}
}
}
public ChunkyTriMesh(float[] verts, int[] tris, int ntris, int trisPerChunk)
{
int nchunks = (ntris + trisPerChunk - 1) / trisPerChunk;
nodes = new List <ChunkyTriMeshNode>(nchunks);
this.ntris = ntris;
// Build tree
BoundsItem[] items = new BoundsItem[ntris];
for (int i = 0; i < ntris; i++)
{
int t = i * 3;
BoundsItem it = items[i] = new BoundsItem();
it.i = i;
// Calc triangle XZ bounds.
it.bmin[0] = it.bmax[0] = verts[tris[t] * 3 + 0];
it.bmin[1] = it.bmax[1] = verts[tris[t] * 3 + 2];
for (int j = 1; j < 3; ++j)
{
int v = tris[t + j] * 3;
if (verts[v] < it.bmin[0])
{
it.bmin[0] = verts[v];
}
if (verts[v + 2] < it.bmin[1])
{
it.bmin[1] = verts[v + 2];
}
if (verts[v] > it.bmax[0])
{
it.bmax[0] = verts[v];
}
if (verts[v + 2] > it.bmax[1])
{
it.bmax[1] = verts[v + 2];
}
}
}
subdivide(items, 0, ntris, trisPerChunk, nodes, tris);
// Calc max tris per node.
maxTrisPerChunk = 0;
foreach (ChunkyTriMeshNode node in nodes)
{
bool isLeaf = node.i >= 0;
if (!isLeaf)
{
continue;
}
if (node.tris.Length / 3 > maxTrisPerChunk)
{
maxTrisPerChunk = node.tris.Length / 3;
}
}
}
