Method chooseKernel

src/gpu.js:146–203

* Choose kernel type and save on .Kernel property of GPU

()

   * Choose kernel type and save on .Kernel property of GPU
   */
  chooseKernel() {
    if (this.Kernel) return;

    /**
     *
     * @type {WebGLKernel|WebGL2Kernel|HeadlessGLKernel|CPUKernel}
     */
    let Kernel = null;

    if (this.context) {
      for (let i = 0; i < kernelOrder.length; i++) {
        const ExternalKernel = kernelOrder[i];
        if (ExternalKernel.isContextMatch(this.context)) {
          if (!ExternalKernel.isSupported) {
            throw new Error(`Kernel type ${ExternalKernel.name} not supported`);
          }
          Kernel = ExternalKernel;
          break;
        }
      }
      if (Kernel === null) {
        throw new Error('unknown Context');
      }
    } else if (this.mode) {
      if (this.mode in internalKernels) {
        if (!validate || internalKernels[this.mode].isSupported) {
          Kernel = internalKernels[this.mode];
        }
      } else if (this.mode === 'gpu') {
        for (let i = 0; i < kernelOrder.length; i++) {
          if (kernelOrder[i].isSupported) {
            Kernel = kernelOrder[i];
            break;
          }
        }
      } else if (this.mode === 'cpu') {
        Kernel = CPUKernel;
      }
      if (!Kernel) {
        throw new Error(`A requested mode of "${this.mode}" and is not supported`);
      }
    } else {
      for (let i = 0; i < kernelOrder.length; i++) {
        if (kernelOrder[i].isSupported) {
          Kernel = kernelOrder[i];
          break;
        }
      }
      if (!Kernel) {
        Kernel = CPUKernel;
      }
    }

    if (!this.mode) {
      this.mode = Kernel.mode;
    }
    this.Kernel = Kernel;
  }