public Subdivide Build(BuildContext data)
{
switch (state)
{
case State.None:
Subdivide c = Initialize(data);
state = (c == null) ? State.Complete : State.Right;
return(c);
case State.Right:
state = State.Finalize;
return(data.Get(isplit, imax));
case State.Finalize:
int iescape = data.curNode - icur;
// Negative index means escape.
data.nodes[inode].i = -iescape;
state = State.Complete;
break;
}
return(null);
}
private Subdivide Initialize(BuildContext data)
{
int inum = imax - imin;
icur = data.curNode;
ChunkyTriMeshNode[] nodes = data.nodes;
BoundsItem[] items = data.items;
if (data.curNode > nodes.Length)
{
return(null);
}
inode = data.curNode++;
if (inum <= data.trisPerChunk)
{
// Leaf
DeriveExtents(items
, imin
, imax
, ref nodes[inode]);
// Copy triangles.
nodes[inode].i = data.curTri;
nodes[inode].count = inum;
for (int i = imin; i < imax; ++i)
{
int pi = items[i].i * 3;
int pd = data.curTri * 3;
data.tris[pd + 0] = data.inTris[pi + 0];
data.tris[pd + 1] = data.inTris[pi + 1];
data.tris[pd + 2] = data.inTris[pi + 2];
data.areas[data.curTri] = data.inAreas[items[i].i];
data.curTri++;
}
}
else
{
// Split
DeriveExtents(items, imin, imax, ref nodes[inode]);
int axis =
(nodes[inode].zmax - nodes[inode].zmin
> nodes[inode].xmax - nodes[inode].xmin)
? 1 : 0;
if (axis == 0)
{
// Sort along x-axis
Array.Sort <BoundsItem>(items, imin, inum, mCompareX);
}
else if (axis == 1)
{
// Sort along y-axis
Array.Sort <BoundsItem>(items, imin, inum, mCompareZ);
}
isplit = imin + inum / 2;
// Left
return(data.Get(imin, isplit));
}
return(null);
}
