/// <summary>
/// In order to build a BspTree, you have to supply the
/// BspTreeBuilder with index an position arrays that are copies of
/// the originals, so that they can be modified during the build
/// process. The supplied epsilon parameter specifies the absolute
/// tolerance value for coplanar triangles.
/// </summary>
public BspTreeBuilder(int[] triangleVertexIndexArray,
V3d[] vertexPositionArray,
double absoluteEpsilon,
int[] triangleAttributeIndexArray)
: base(null, triangleVertexIndexArray, triangleAttributeIndexArray)
{
m_weightsArray = new WeightedIndex[0][];
m_positionArray = vertexPositionArray;
TriangleCountMul3 = m_triangleVertexIndexArray.Length;
int triangleCount = TriangleCountMul3 / 3;
VertexCount = m_positionArray.Length;
m_absoluteEpsilon = absoluteEpsilon;
m_originalVertexCount = VertexCount;
// simple shuffle-algorithm (imagine the array as a square
// from left->right, top->bottom)
// address the array now top->bottom, left->right
int stride = (int)Fun.Ceiling(Fun.Sqrt(triangleCount + 1.0));
for (int offset = 0; offset < stride; offset++)
{
for (int ti = offset; ti < triangleCount; ti += stride)
{
BspNode.AddTriangle(this, ti * 3, ref m_tree);
}
}
TriangleCountMul3 = m_tree.TriangleCount() * 3;
}
internal static void AddTriangle(
BspTreeBuilder builder, int tiMul3, ref Triangle3d tr, V3d triangleNormal,
ref BspNode node)
{
if (node != null)
{
node.AddTriangle(builder, tiMul3, ref tr, triangleNormal);
}
else
{
node = new BspNode(tiMul3, tr.P0, triangleNormal);
}
}