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| var GreedyMesh = (function greedyLoader() {
// contains all forward faces (in terms of scan direction)
var mask = new Int32Array(4096);
// and all backwards faces. needed when there are two transparent blocks
// next to each other.
var invMask = new Int32Array(4096);
// setting 16th bit if transparent
var kTransparentMask = 0x8000;
var kNoFlagsMask = 0x7FFF;
var kTransparentTypes = [];
kTransparentTypes[16] = true
function isTransparent(v) {
return (v & kTransparentMask) === kTransparentMask;
}
function removeFlags(v) {
return (v & kNoFlagsMask);
}
return function ohSoGreedyMesher(volume, dims, mesherExtraData) {
var vertices = [], faces = []
, dimsX = dims[0]
, dimsY = dims[1]
, dimsXY = dimsX * dimsY;
var tVertices = [], tFaces = []
var transparentTypes = mesherExtraData ? (mesherExtraData.transparentTypes || {}) : {};
var getType = function(voxels, offset) {
var type = voxels[offset];
return type | (type in transparentTypes ? kTransparentMask : 0);
}
//Sweep over 3-axes
for(var d=0; d<3; ++d) {
var i, j, k, l, w, W, h, n, c
, u = (d+1)%3
, v = (d+2)%3
, x = [0,0,0]
, q = [0,0,0]
, du = [0,0,0]
, dv = [0,0,0]
, dimsD = dims[d]
, dimsU = dims[u]
, dimsV = dims[v]
, qdimsX, qdimsXY
, xd
if (mask.length < dimsU * dimsV) {
mask = new Int32Array(dimsU * dimsV);
invMask = new Int32Array(dimsU * dimsV);
}
q[d] = 1;
x[d] = -1;
qdimsX = dimsX * q[1]
qdimsXY = dimsXY * q[2]
// Compute mask
while (x[d] < dimsD) {
xd = x[d]
n = 0;
for(x[v] = 0; x[v] < dimsV; ++x[v]) {
for(x[u] = 0; x[u] < dimsU; ++x[u], ++n) {
// Modified to read through getType()
var a = xd >= 0 && getType(volume, x[0] + dimsX * x[1] + dimsXY * x[2] )
, b = xd < dimsD-1 && getType(volume, x[0]+q[0] + dimsX * x[1] + qdimsX + dimsXY * x[2] + qdimsXY)
// both are transparent, add to both directions
if (isTransparent(a) && isTransparent(b)) {
mask[n] = a;
invMask[n] = b;
// if a is solid and b is not there or transparent
} else if (a && (!b || isTransparent(b))) {
mask[n] = a;
invMask[n] = 0
// if b is solid and a is not there or transparent
} else if (b && (!a || isTransparent(a))) {
mask[n] = 0
invMask[n] = b;
// dont draw this face
} else {
mask[n] = 0
invMask[n] = 0
}
}
}
++x[d];
// Generate mesh for mask using lexicographic ordering
function generateMesh(mask, dimsV, dimsU, vertices, faces, clockwise) {
clockwise = clockwise === undefined ? true : clockwise;
var n, j, i, c, w, h, k, du = [0,0,0], dv = [0,0,0];
n = 0;
for (j=0; j < dimsV; ++j) {
for (i=0; i < dimsU; ) {
c = mask[n];
if (!c) {
i++; n++; continue;
}
//Compute width
w = 1;
while (c === mask[n+w] && i+w < dimsU) w++;
//Compute height (this is slightly awkward)
for (h=1; j+h < dimsV; ++h) {
k = 0;
while (k < w && c === mask[n+k+h*dimsU]) k++
if (k < w) break;
}
// Add quad
// The du/dv arrays are reused/reset
// for each iteration.
du[d] = 0; dv[d] = 0;
x[u] = i; x[v] = j;
if (clockwise) {
// if (c > 0) {
dv[v] = h; dv[u] = 0;
du[u] = w; du[v] = 0;
} else {
// c = -c;
du[v] = h; du[u] = 0;
dv[u] = w; dv[v] = 0;
}
// ## enable code to ensure that transparent faces are last in the list
// if (!isTransparent(c)) {
var vertex_count = vertices.length;
vertices.push([x[0], x[1], x[2] ]);
vertices.push([x[0]+du[0], x[1]+du[1], x[2]+du[2] ]);
vertices.push([x[0]+du[0]+dv[0], x[1]+du[1]+dv[1], x[2]+du[2]+dv[2]]);
vertices.push([x[0] +dv[0], x[1] +dv[1], x[2] +dv[2]]);
faces.push([vertex_count, vertex_count+1, vertex_count+2, vertex_count+3, removeFlags(c)]);
// } else {
// var vertex_count = tVertices.length;
// tVertices.push([x[0], x[1], x[2] ]);
// tVertices.push([x[0]+du[0], x[1]+du[1], x[2]+du[2] ]);
// tVertices.push([x[0]+du[0]+dv[0], x[1]+du[1]+dv[1], x[2]+du[2]+dv[2]]);
// tVertices.push([x[0] +dv[0], x[1] +dv[1], x[2] +dv[2]]);
// tFaces.push([vertex_count, vertex_count+1, vertex_count+2, vertex_count+3, removeFlags(c)]);
// }
//Zero-out mask
W = n + w;
for(l=0; l<h; ++l) {
for(k=n; k<W; ++k) {
mask[k+l*dimsU] = 0;
}
}
//Increment counters and continue
i += w; n += w;
}
}
}
generateMesh(mask, dimsV, dimsU, vertices, faces, true)
generateMesh(invMask, dimsV, dimsU, vertices, faces, false)
}
}
// ## enable code to ensure that transparent faces are last in the list
// var vertex_count = vertices.length;
// var newFaces = tFaces.map(function(v) {
// return [vertex_count+v[0], vertex_count+v[1], vertex_count+v[2], vertex_count+v[3], v[4]]
// })
//
// return { vertices:vertices.concat(tVertices), faces:faces.concat(newFaces) };
// TODO: Try sorting by texture to see if we can reduce draw calls.
// faces.sort(function sortFaces(a, b) {
// return b[4] - a[4];
// })
return { vertices:vertices, faces:faces };
}
})();
Eif(exports) {
exports.mesher = GreedyMesh;
}
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