Function readPixelWebGL

src/webgl/utils.js:87–103

(gl, framebuffer, x, y, format, type, flipY)

 * @returns {Number[]} pixels The channel data for the pixel at that location
 */
export function readPixelWebGL(gl, framebuffer, x, y, format, type, flipY) {
  // Record the currently bound framebuffer so we can go back to it after, and
  // bind the framebuffer we want to read from
  const prevFramebuffer = gl.getParameter(gl.FRAMEBUFFER_BINDING);
  gl.bindFramebuffer(gl.FRAMEBUFFER, framebuffer);

  const channels = format === gl.RGBA ? 4 : 3;
  const TypedArrayClass = type === gl.UNSIGNED_BYTE ? Uint8Array : Float32Array;
  const pixels = new TypedArrayClass(channels);

  gl.readPixels(x, flipY ? flipY - y - 1 : y, 1, 1, format, type, pixels);

  // Re-bind whatever was previously bound
  gl.bindFramebuffer(gl.FRAMEBUFFER, prevFramebuffer);

  return Array.from(pixels);
}

export function setWebGLTextureParams(texture, gl, webglVersion) {
  texture.bindTexture();