Method constructor

tfjs-backend-webgl/src/pad_gpu.ts:27–70

(
      xShape: number[], paddings: Array<[number, number]>,
      constantValue: number)

  customUniforms = [{name: 'value', type: 'float' as UniformType}];

  constructor(
      xShape: number[], paddings: Array<[number, number]>,
      constantValue: number) {
    this.outputShape = paddings.map(
        (p, i) => p[0] /* beforePad */ + xShape[i] + p[1] /* afterPad */);
    const rank = xShape.length;
    const type = getCoordsDataType(rank);

    const start = paddings.map(p => p[0]).join(',');
    const end = paddings.map((p, i) => p[0] + xShape[i]).join(',');
    const unpackedCoords =
        ['coords[0]', 'coords[1]', 'coords[2]', 'coords[3]'].slice(0, rank);

    if (rank === 1) {
      this.userCode = `
        int start = ${start};
        int end = ${end};

        void main() {
          int outC = getOutputCoords();
          if (outC < start || outC >= end) {
            setOutput(value);
          } else {
            setOutput(getX(outC - start));
          }
        }
      `;
      return;
    }
    this.userCode = `
      ${type} start = ${type}(${start});
      ${type} end = ${type}(${end});

      void main() {
        ${type} outC = getOutputCoords();
        if (any(lessThan(outC, start)) || any(greaterThanEqual(outC, end))) {
          setOutput(value);
        } else {
          ${type} coords = outC - start;
          setOutput(getX(${unpackedCoords}));
        }
      }
    `;
  }
}