//MarchCube performs the Marching Cubes algorithm on a single cube
static void MarchCube(Vector3 pos, float[] cube, List <Vector3> vertList, List <int> indexList, ThreadSafeVoxelisation.Voxelization.AABCGrid grid, Dictionary <string, int> indices, KDTree surface, List <Vector3> parentVerts)
{
int i, j, vert, idx;
int flagIndex = 0;
float offset = 0.0f;
ThreadSafeVoxelisation.GridSize gridSize = grid.GetSize();
Vector3[] edgeVertex = new Vector3[12];
//Find which vertices are inside of the surface and which are outside
for (i = 0; i < 8; i++)
{
if (cube[i] <= target)
{
flagIndex |= 1 << i;
}
}
//Find which edges are intersected by the surface
int edgeFlags = cubeEdgeFlags[flagIndex];
//If the cube is entirely inside or outside of the surface, then there will be no intersections
if (edgeFlags == 0)
{
return;
}
//Find the point of intersection of the surface with each edge
for (i = 0; i < 12; i++)
{
//if there is an intersection on this edge
if ((edgeFlags & (1 << i)) != 0)
{
offset = GetOffset(cube[edgeConnection[i, 0]], cube[edgeConnection[i, 1]]);
edgeVertex[i].x = pos.x + (vertexOffset[edgeConnection[i, 0], 0] + offset * edgeDirection[i, 0]);
edgeVertex[i].y = pos.y + (vertexOffset[edgeConnection[i, 0], 1] + offset * edgeDirection[i, 1]);
edgeVertex[i].z = pos.z + (vertexOffset[edgeConnection[i, 0], 2] + offset * edgeDirection[i, 2]);
}
}
//Save the triangles that were found. There can be up to five per cube
/*for (i = 0; i < 5; i++) {
* if (triangleConnectionTable[flagIndex, 3 * i] < 0) break;
*
* for (j = 0; j < 3; j++) {
* idx = vertList.Count;
* vert = triangleConnectionTable[flagIndex, 3 * i + windingOrder[j]];
*
* Vector3 vertex = edgeVertex[vert];
* string points = vertex.x + "" + vertex.y + "" + vertex.z;
* int index = -1;
*
* bool found = indices.TryGetValue(points, out index);
*
* if (found) {
* indexList.Add(index);
* } else {
* indexList.Add(idx);
* vertList.Add(edgeVertex[vert]);
* indices.Add(points, idx);
* }
* }
*
* }*/
for (i = 0; i < 5; i++)
{
if (triangleConnectionTable[flagIndex, 3 * i] < 0)
{
break;
}
idx = vertList.Count;
for (j = 0; j < 3; j++)
{
vert = triangleConnectionTable[flagIndex, 3 * i + j];
indexList.Add(idx + windingOrder[j]);
vertList.Add(edgeVertex[vert]);
}
}
}