function mesh (params) { const dims = params.dims const vertices = [] const indices = [] const normals = [] for (let backFace = true, b = false; b !== backFace; backFace = backFace && b, b = !b) { // Sweep over 3-axes for (let d = 0; d < 3; ++d) { let i, j, k, l, w, h, side const u = (d + 1) % 3 const v = (d + 2) % 3 const x = [0, 0, 0] const q = [0, 0, 0] // Here we're keeping track of the side that we're meshing. if (d === 0) side = backFace ? LEFT : RIGHT else if (d === 1) side = backFace ? BOTTOM : TOP else if (d === 2) side = backFace ? BACK : FRONT const mask = new Int32Array(dims[u] * dims[v]) q[d] = 1 // Move through the dimension from front to back for (x[d] = -1; x[d] < dims[d];) { // Compute mask let n = 0 for (x[v] = 0; x[v] < dims[v]; ++x[v]) { for (x[u] = 0; x[u] < dims[u]; ++x[u]) { const current = this.getBlockAt(params, dims, x[0], x[1], x[2]) const ajacent = this.getBlockAt(params, dims, x[0] + q[0], x[1] + q[1], x[2] + q[2]) mask[n++] = ((current && ajacent && current === ajacent)) ? null : (backFace ? ajacent : current) } } // Increment x[d] ++x[d] // Generate mesh for mask using lexicographic ordering n = 0 for (j = 0; j < dims[v]; ++j) { for (i = 0; i < dims[u];) { if (mask[n]) { // Compute width for (w = 1; mask[n + w] && mask[n + w] === mask[n] && i + w < dims[u]; ++w) {} // Compute height let done = false for (h = 1; j + h < dims[v]; ++h) { for (k = 0; k < w; ++k) { if (!mask[n + k + h * dims[u]] || mask[n + k + h * dims[u]] !== mask[n]) { done = true break } } if (done) break } // Create quad x[u] = i x[v] = j const du = [0, 0, 0] du[u] = w const dv = [0, 0, 0] dv[v] = h const quad = [ [x[0], x[1], x[2]], [x[0] + du[0], x[1] + du[1], x[2] + du[2]], [x[0] + du[0] + dv[0], x[1] + du[1] + dv[1], x[2] + du[2] + dv[2]], [x[0] + dv[0], x[1] + dv[1], x[2] + dv[2]] ] // Add vertices and normals const mul = backFace ? -1 : 1 for (var qindex = 0; qindex < 4; ++qindex) { vertices.push(quad[qindex][0], quad[qindex][1], quad[qindex][2]) normals.push(q[0] * mul, q[1] * mul, q[2] * mul) } // Add indices const indexi = vertices.length / 3 - 4 if (backFace) { indices.push(indexi + 2, indexi + 1, indexi) indices.push(indexi + 3, indexi + 2, indexi) } else { indices.push(indexi, indexi + 1, indexi + 2) indices.push(indexi, indexi + 2, indexi + 3) } // Zero-out mask for (l = 0; l < h; ++l) { for (k = 0; k < w; ++k) { mask[n + k + l * dims[u]] = false } } // Increment counters and continue i += w n += w } else { ++i ++n } } } } } } return { vertices, indices, normals } } }