Function Buffer

packages/engine/Source/Renderer/Buffer.js:14–73

* @private

(options)

 * @private
 */
function Buffer(options) {
  options = options ?? Frozen.EMPTY_OBJECT;

  //>>includeStart('debug', pragmas.debug);
  Check.defined("options.context", options.context);

  if (!defined(options.typedArray) && !defined(options.sizeInBytes)) {
    throw new DeveloperError(
      "Either options.sizeInBytes or options.typedArray is required.",
    );
  }

  if (defined(options.typedArray) && defined(options.sizeInBytes)) {
    throw new DeveloperError(
      "Cannot pass in both options.sizeInBytes and options.typedArray.",
    );
  }

  if (defined(options.typedArray)) {
    Check.typeOf.object("options.typedArray", options.typedArray);
    Check.typeOf.number(
      "options.typedArray.byteLength",
      options.typedArray.byteLength,
    );
  }

  if (!BufferUsage.validate(options.usage)) {
    throw new DeveloperError("usage is invalid.");
  }
  //>>includeEnd('debug');

  const gl = options.context._gl;
  const bufferTarget = options.bufferTarget;
  const typedArray = options.typedArray;
  let sizeInBytes = options.sizeInBytes;
  const usage = options.usage;
  const hasArray = defined(typedArray);

  if (hasArray) {
    sizeInBytes = typedArray.byteLength;
  }

  //>>includeStart('debug', pragmas.debug);
  Check.typeOf.number.greaterThan("sizeInBytes", sizeInBytes, 0);
  //>>includeEnd('debug');

  const buffer = gl.createBuffer();
  gl.bindBuffer(bufferTarget, buffer);
  gl.bufferData(bufferTarget, hasArray ? typedArray : sizeInBytes, usage);
  gl.bindBuffer(bufferTarget, null);

  this._id = createGuid();
  this._gl = gl;
  this._webgl2 = options.context._webgl2;
  this._bufferTarget = bufferTarget;
  this._sizeInBytes = sizeInBytes;
  this._usage = usage;
  this._buffer = buffer;