playcanvas
Version:
Open-source WebGL/WebGPU 3D engine for the web
52 lines (51 loc) • 1.59 kB
JavaScript
import { BUFFERUSAGE_COPY_DST, BUFFERUSAGE_INDIRECT } from "../constants.js";
import { StorageBuffer } from "../storage-buffer.js";
class WebgpuDrawCommands {
device;
gpuIndirect = null;
gpuIndirectSigned = null;
storage = null;
constructor(device) {
this.device = device;
}
allocate(maxCount) {
if (this.gpuIndirect && this.gpuIndirect.length === 5 * maxCount) {
return;
}
this.storage?.destroy();
this.gpuIndirect = new Uint32Array(5 * maxCount);
this.gpuIndirectSigned = new Int32Array(this.gpuIndirect.buffer);
this.storage = new StorageBuffer(this.device, this.gpuIndirect.byteLength, BUFFERUSAGE_INDIRECT | BUFFERUSAGE_COPY_DST);
}
add(i, indexOrVertexCount, instanceCount, firstIndexOrVertex, baseVertex = 0, firstInstance = 0) {
const o = i * 5;
this.gpuIndirect[o + 0] = indexOrVertexCount;
this.gpuIndirect[o + 1] = instanceCount;
this.gpuIndirect[o + 2] = firstIndexOrVertex;
this.gpuIndirectSigned[o + 3] = baseVertex;
this.gpuIndirect[o + 4] = firstInstance;
}
update(count) {
if (this.storage && count > 0) {
const used = count * 5;
this.storage.write(0, this.gpuIndirect, 0, used);
}
let totalPrimitives = 0;
if (this.gpuIndirect && count > 0) {
for (let d = 0; d < count; d++) {
const offset = d * 5;
const indexOrVertexCount = this.gpuIndirect[offset + 0];
const instanceCount = this.gpuIndirect[offset + 1];
totalPrimitives += indexOrVertexCount * instanceCount;
}
}
return totalPrimitives;
}
destroy() {
this.storage?.destroy();
this.storage = null;
}
}
export {
WebgpuDrawCommands
};