public TransitionCache()
{
const int cacheSize = 0; // 2 * TransvoxelExtractor.BlockWidth * TransvoxelExtractor.BlockWidth;
_cache = new ReuseCell[cacheSize];
for (int i = 0; i < cacheSize; i++)
{
_cache[i] = new ReuseCell(12);
}
}
public RegularCellCache(int chunksize)
{
this.chunkSize = chunksize;
_cache = new ReuseCell[2][];
_cache[0] = new ReuseCell[chunkSize * chunkSize];
_cache[1] = new ReuseCell[chunkSize * chunkSize];
for (int i = 0; i < chunkSize * chunkSize; i++)
{
_cache[0][i] = new ReuseCell(4);
_cache[1][i] = new ReuseCell(4);
}
}
private void PolygonizeCell(Vector3int16 offsetPos, Vector3int16 pos, ref List <TerrainVertex> vertices,
ref List <ushort> indices, int lod)
{
Debug.Assert(lod >= 1, "Level of Detail must be greater than 1");
offsetPos *= Terrain.ChunkSize;
offsetPos += pos * lod;
byte directionMask = (byte)((pos.x > 0 ? 1 : 0) | ((pos.z > 0 ? 1 : 0) << 1) | ((pos.y > 0 ? 1 : 0) << 2));
sbyte[] density = new sbyte[8];
for (int i = 0; i < density.Length; i++)
{
density[i] = _volume[offsetPos + CornerIndex[i] * lod].Density;
}
byte caseCode = GetCaseCode(density);
if ((caseCode ^ ((density[7] >> 7) & 0xFF)) == 0) //for this cases there is no triangulation
{
return;
}
var cornerNormals = new Vector3[8];
for (int i = 0; i < 8; i++)
{
var p = offsetPos + CornerIndex[i] * lod;
float nx = (_volume.GetCell(p.x + 1, p.y, p.z).Density - _volume[p - Vector3int16.Right].Density) * 0.5f;
float ny = (_volume[p + Vector3int16.Up].Density - _volume[p - Vector3int16.Up].Density) * 0.5f;
float nz = (_volume[p + Vector3int16.Backward].Density - _volume[p - Vector3int16.Backward].Density) * 0.5f;
cornerNormals[i].Set(nx, ny, nz);
cornerNormals[i].Normalize();
}
byte regularCellClass = RegularCellClass[caseCode];
ushort[] vertexLocations = RegularVertexData[caseCode];
var c = RegularCellData[regularCellClass];
long vertexCount = c.GetVertexCount();
long triangleCount = c.GetTriangleCount();
byte[] indexOffset = c.Indices(); //index offsets for current cell
ushort[] mappedIndizes = new ushort[indexOffset.Length]; //array with real indizes for current cell
for (int i = 0; i < vertexCount; i++)
{
byte edge = (byte)(vertexLocations[i] >> 8);
byte reuseIndex = (byte)(edge & 0xF); //Vertex id which should be created or reused 1,2 or 3
byte rDir = (byte)(edge >> 4); //the direction to go to reach a previous cell for reusing
byte v1 = (byte)((vertexLocations[i]) & 0x0F); //Second Corner Index
byte v0 = (byte)((vertexLocations[i] >> 4) & 0x0F); //First Corner Index
sbyte d0 = density[v0];
sbyte d1 = density[v1];
//Vector3f n0 = cornerNormals[v0];
//Vector3f n1 = cornerNormals[v1];
Debug.Assert(v1 > v0);
int t = (d1 << 8) / (d1 - d0);
int u = 0x0100 - t;
float t0 = t / 256f;
float t1 = u / 256f;
int index = -1;
if (UseCache && v1 != 7 && (rDir & directionMask) == rDir)
{
Debug.Assert(reuseIndex != 0);
ReuseCell cell = _cache.GetReusedIndex(pos, rDir);
index = cell.Verts[reuseIndex];
}
if (index == -1)
{
var normal = cornerNormals[v0] * t0 + cornerNormals[v1] * t1;
GenerateVertex(ref offsetPos, ref pos, ref vertices, lod, t, ref v0, ref v1, ref d0, ref d1, ref normal);
index = vertices.Count - 1;
}
if ((rDir & 8) != 0)
{
_cache.SetReusableIndex(pos, reuseIndex, (ushort)(vertices.Count - 1));
}
mappedIndizes[i] = (ushort)index;
}
for (int t = 0; t < triangleCount; t++)
{
for (int i = 0; i < 3; i++)
{
indices.Add(mappedIndizes[c.Indices()[t * 3 + i]]);
}
}
}