public static MeshData CreateGreedyMesh(Chunk chunk)
{
var meshData = new MeshData();
int size = Chunk.Size;
var world = chunk.World;
var offset = chunk.Position * Chunk.Size;
Block block1;
Block block2;
for (bool backFace = true, b = false; b != backFace; backFace = backFace && b, b = !b)
{
for (int d = 0; d < 3; d++)
{
int i, j, k, l, w, h, u = (d + 1) % 3, v = (d + 2) % 3;
int[] x = new int[3];
int[] q = new int[3];
int[] mask = new int[size * size];
Direction side = Direction.Left;
if (d == 0)
{
side = backFace ? Direction.Left : Direction.Right;
}
else if (d == 1)
{
side = backFace ? Direction.Down : Direction.Up;
}
else if (d == 2)
{
side = backFace ? Direction.Back : Direction.Forward;
}
q[d] = 1;
for (x[d] = -1; x[d] < size;)
{
// Compute the mask
int n = 0;
for (x[v] = 0; x[v] < size; ++x[v])
{
for (x[u] = 0; x[u] < size; ++x[u])
{
var block1Pos = new Vector3Int(x[0], x[1], x[2]) + offset;
var block2Pos = new Vector3Int(x[0] + q[0], x[1] + q[1], x[2] + q[2]) + offset;
block1 = world.GetBlock(block1Pos); // 0 <= x[d] ? WorldManager.Active.GetBlock(new Vecx[0], x[1], x[2]]) : Block.Null;
block2 = world.GetBlock(block2Pos); //x[d] < size - 1 ? chunk[x[0] + q[0], x[1] + q[1], x[2] + q[2]] : Block.Null;
var one = BlockManager.GetNumericalId(block1.Definition.Identifier);
var two = BlockManager.GetNumericalId(block2.Definition.Identifier);
if ((one != 0) == (two != 0))
{
mask[n] = 0;
}
else if (one != 0)
{
mask[n] = one;
}
else
{
mask[n] = -two;
}
n++;
}
}
// Increment x[d]
++x[d];
// Generate mesh for mask using lexicographic ordering
n = 0;
for (j = 0; j < size; ++j)
{
for (i = 0; i < size;)
{
var c = mask[n];
if (c != 0)
{
// Compute width
for (w = 1; i + w < size && mask[n + w] == c; ++w)
{
;
}
// Compute height (this is slightly awkward
var done = false;
for (h = 1; j + h < size; ++h)
{
for (k = 0; k < w; ++k)
{
if (c != mask[n + k + h * size])
{
done = true;
break;
}
}
if (done)
{
break;
}
}
// Add quad
x[u] = i;
x[v] = j;
int[] du = new int[3];
int[] dv = new int[3];
dv[v] = h;
du[u] = w;
c = c <= 0 ? -c : c;
AddFace(new Vector3(x[0], x[1], x[2]),
new Vector3(x[0] + du[0], x[1] + du[1], x[2] + du[2]),
new Vector3(x[0] + du[0] + dv[0], x[1] + du[1] + dv[1], x[2] + du[2] + dv[2]),
new Vector3(x[0] + dv[0], x[1] + dv[1], x[2] + dv[2]), BlockManager.GetBlock(c), side, w, h, backFace, meshData);
// Zero-out mask
for (l = 0; l < h; ++l)
{
for (k = 0; k < w; ++k)
{
mask[n + k + l * size] = 0;
}
}
// Increment counters and continue
i += w;
n += w;
}
else
{
++i;
++n;
}
}
}
}
}
}
chunk.Dirty = false;
chunk.Rendered = true;
return(meshData);
}
private static void AddFace(Vector3 v1, Vector3 v2, Vector3 v3, Vector3 v4, BlockDefinition blockDefinition, Direction side, int width, int height, bool back, MeshData meshData)
{
int index = meshData.Vertices.Count;
int layer = blockDefinition.GetTexture(side).Layer;
meshData.AddVertex(v1);
meshData.AddVertex(v2);
meshData.AddVertex(v3);
meshData.AddVertex(v4);
if (side == Direction.Forward || side == Direction.Back)
{
meshData.AddUV(new Vector3(0, 0, layer));
meshData.AddUV(new Vector3(width, 0, layer));
meshData.AddUV(new Vector3(width, height, layer));
meshData.AddUV(new Vector3(0, height, layer));
}
else
{
meshData.AddUV(new Vector3(0, 0, layer));
meshData.AddUV(new Vector3(0, width, layer));
meshData.AddUV(new Vector3(height, width, layer));
meshData.AddUV(new Vector3(height, 0, layer));
}
if (back)
{
meshData.AddTriangle(0, index);
meshData.AddTriangle(0, index + 3);
meshData.AddTriangle(0, index + 2);
meshData.AddTriangle(0, index + 2);
meshData.AddTriangle(0, index + 1);
meshData.AddTriangle(0, index);
return;
}
meshData.AddTriangle(0, index);
meshData.AddTriangle(0, index + 1);
meshData.AddTriangle(0, index + 2);
meshData.AddTriangle(0, index + 2);
meshData.AddTriangle(0, index + 3);
meshData.AddTriangle(0, index);
}
