private void GetBVHVerticesAndIndices(BVHNode bvh, int level = 0)
{
var vertBase = _bvhVerts.Count;
var corners = bvh.Bounds.GetCorners();
if (level == 9) {
_bvhVerts.AddRange(corners.Select(c => {
var color = Color.White;
switch (_aabCount % 4) {
case 1:
color = Color.Blue;
break;
case 2:
color = Color.Magenta;
break;
case 3:
color = Color.Yellow;
break;
}
return new VertexPC(c, color);
}));
_aabCount++;
_bvhIndices.AddRange(
new[] {0, 1, 1, 2, 2, 3, 3, 0, 4, 5, 5, 6, 6, 7, 7, 4, 4, 0, 5, 1, 7, 3, 6, 2}.Select(
i => i + vertBase));
}
if (bvh.Children!=null) {
foreach (var child in bvh.Children) {
GetBVHVerticesAndIndices(child, level+1);
}
}
}
private BVHNode BuildBvh(Vector2 tl, Vector2 br)
{
var minMaxY = GetMinMaxY(tl, br);
var minX = tl.X*Info.CellSpacing - Width/2;
var maxX = br.X*Info.CellSpacing - Width/2;
var minZ = -tl.Y * Info.CellSpacing + Depth / 2;
var maxZ = -br.Y * Info.CellSpacing + Depth / 2;
var bvh = new BVHNode {Bounds = new BoundingBox(new Vector3(minX, minMaxY.X, minZ), new Vector3(maxX, minMaxY.Y, maxZ))};
var width = (int)Math.Floor((br.X - tl.X)/2);
var depth = (int)Math.Floor((br.Y - tl.Y)/2);
if (width >= 4 && depth >= 4) {
bvh.Children = new[] {
BuildBvh(tl, new Vector2(tl.X + width, tl.Y + depth)),
BuildBvh(new Vector2(tl.X + width, tl.Y), new Vector2(br.X, tl.Y + depth) ),
BuildBvh(new Vector2(tl.X, tl.Y+depth), new Vector2(tl.X+depth, br.Y) ),
BuildBvh(new Vector2(tl.X+width, tl.Y+depth), br )
};
}
return bvh;
}