@openhps/core/dist/esm/three/renderers/common/BufferUtils.js

Open Hybrid Positioning System - Core component

import { GPU_CHUNK_BYTES } from './Constants.js';

/**
 * This function is usually called with the length in bytes of an array buffer.
 * It returns an padded value which ensure chunk size alignment according to STD140 layout.
 *
 * @function
 * @param {number} floatLength - The buffer length.
 * @return {number} The padded length.
 */
function getFloatLength(floatLength) {
  // ensure chunk size alignment (STD140 layout)

  return floatLength + (GPU_CHUNK_BYTES - floatLength % GPU_CHUNK_BYTES) % GPU_CHUNK_BYTES;
}

/**
 * Given the count of vectors and their vector length, this function computes
 * a total length in bytes with buffer alignment according to STD140 layout.
 *
 * @function
 * @param {number} count - The number of vectors.
 * @param {number} [vectorLength=4] - The vector length.
 * @return {number} The padded length.
 */
function getVectorLength(count, vectorLength = 4) {
  const strideLength = getStrideLength(vectorLength);
  const floatLength = strideLength * count;
  return getFloatLength(floatLength);
}

/**
 * This function is called with a vector length and ensure the computed length
 * matches a predefined stride (in this case `4`).
 *
 * @function
 * @param {number} vectorLength - The vector length.
 * @return {number} The padded length.
 */
function getStrideLength(vectorLength) {
  const strideLength = 4;
  return vectorLength + (strideLength - vectorLength % strideLength) % strideLength;
}
export { getFloatLength, getVectorLength, getStrideLength };