Method createShadeInternal

web/src/webgpu.ts:649–856

* Internal impl of createShader for both async and sync mode. * * @param finfo The function information already parsed as a record. * @param code The shader data(in WGSL) * @param asyncMode Whether use async mode. * @returns The shader function or promise of shader func.

(
    finfo: FunctionInfo,
    code: string,
    asyncMode: boolean
  )

   * @returns The shader function or promise of shader func.
   */
  private createShadeInternal(
    finfo: FunctionInfo,
    code: string,
    asyncMode: boolean
  ): Function | Promise<Function> {
    const dispatchToDim: Array<number> = [];
    let paramWriteAccess: Array<number> = [];

    for (let i = 0; i < finfo.launch_param_tags.length; ++i) {
      const tag: string = finfo.launch_param_tags[i];
      if (tag.startsWith("blockIdx.")) {
        const target: number = tag.charCodeAt(tag.length - 1) - ("x".charCodeAt(0));
        assert(target >= 0 && target < 3);
        dispatchToDim.push(target);
      } else if (tag.startsWith("threadIdx.")) {
        const target: number = tag.charCodeAt(tag.length - 1) - ("x".charCodeAt(0));
        assert(target >= 0 && target < 3);
        dispatchToDim.push(target + 3);
      } else if (tag.startsWith("paramWriteAccess:")) {
        paramWriteAccess = JSON.parse(tag.substring(17));
      } else {
        throw new Error("Cannot handle thread_axis " + tag);
      }
    }


    const layoutEntries: Array<GPUBindGroupLayoutEntry> = [];
    const bufferArgIndices: Array<number> = [];
    const podArgIndices: Array<number> = [];

    for (let i = 0; i < finfo.arg_types.length; ++i) {
      const dtype = finfo.arg_types[i];
      if (dtype == "handle") {
        layoutEntries.push({
          binding: bufferArgIndices.length,
          visibility: GPUShaderStage.COMPUTE,
          buffer: {
            type: paramWriteAccess[bufferArgIndices.length] ? "storage" : "read-only-storage"
          }
        });
        bufferArgIndices.push(i);
      } else if (dtype.startsWith("int") || dtype.startsWith("uint") || dtype.startsWith("float")) {
        podArgIndices.push(i);
      } else {
        throw new Error("Cannot handle argument type " + dtype + " in WebGPU shader");
      }
    }

    assert(paramWriteAccess.length == bufferArgIndices.length);
    // POD arguments are pass in the end
    layoutEntries.push({
      binding: bufferArgIndices.length,
      visibility: GPUShaderStage.COMPUTE,
      buffer: {
        type: "uniform"
      }
    });