Function doReftest

test/reftest.js:23–90

()

}

function doReftest() {
  if (reftestBlocked) return;
  if (doReftest.done) return;
  if (reportResultToServer.reported) return;
  doReftest.done = true;
  var img = new Image();
  img.onload = () => {
    assert(img.width == Module['canvas'].width, `Invalid width: ${Module['canvas'].width}, should be ${img.width}`);
    assert(img.height == Module['canvas'].height, `Invalid height: ${Module['canvas'].height}, should be ${img.height}`);

    var canvas = document.createElement('canvas');
    canvas.width = img.width;
    canvas.height = img.height;
    var ctx = canvas.getContext('2d');
    ctx.drawImage(img, 0, 0);
    var expected = ctx.getImageData(0, 0, img.width, img.height).data;

    var actualUrl = Module['canvas'].toDataURL();
    var actualImage = new Image();
    actualImage.onload = () => {
      /*
      document.body.appendChild(img); // for comparisons
      var div = document.createElement('div');
      div.innerHTML = '^=expected, v=actual';
      document.body.appendChild(div);
      document.body.appendChild(actualImage); // to grab it for creating the test reference
      */

      var actualCanvas = document.createElement('canvas');
      actualCanvas.width = actualImage.width;
      actualCanvas.height = actualImage.height;
      var actualCtx = actualCanvas.getContext('2d');
      actualCtx.drawImage(actualImage, 0, 0);
      var actual = actualCtx.getImageData(0, 0, actualImage.width, actualImage.height).data;

      // Allow each pixel R,G,B component to be off by a few units to account for possible shading
      // differences between GPUs.
      function dampenError(error) {
        return Math.max(error-2, 0);
      }

      var total = 0;
      var width = img.width;
      var height = img.height;
      for (var x = 0; x < width; x++) {
        for (var y = 0; y < height; y++) {
          total += dampenError(Math.abs(expected[y*width*4 + x*4 + 0] - actual[y*width*4 + x*4 + 0]));
          total += dampenError(Math.abs(expected[y*width*4 + x*4 + 1] - actual[y*width*4 + x*4 + 1]));
          total += dampenError(Math.abs(expected[y*width*4 + x*4 + 2] - actual[y*width*4 + x*4 + 2]));
        }
      }
      // floor, to allow some margin of error for antialiasing
      var wrong = Math.floor(total / (img.width*img.height*3));
      if (wrong || reftestRebaseline) {
        // Generate a png of the actual rendered image and send it back
        // to the server.
        Module['canvas'].toBlob((blob) => {
          sendFileToServer('actual.png', blob);