palemoon-dev/platform/devtools/client/shadereditor/test/browser_webgl-actor-test-18.js

/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

/**
 * Tests the `getPixel` actor method works across threads.
 */

function* ifWebGLSupported() {
  let { target, front } = yield initBackend(MULTIPLE_CONTEXTS_URL);
  front.setup({ reload: true });

  yield getPrograms(front, 2);

  // Wait a frame to ensure rendering
  yield front.waitForFrame();

  let pixel = yield front.getPixel({ selector: "#canvas1", position: { x: 0, y: 0 }});
  is(pixel.r, 255, "correct `r` value for first canvas.");
  is(pixel.g, 255, "correct `g` value for first canvas.");
  is(pixel.b, 0, "correct `b` value for first canvas.");
  is(pixel.a, 255, "correct `a` value for first canvas.");

  pixel = yield front.getPixel({ selector: "#canvas2", position: { x: 0, y: 0 }});
  is(pixel.r, 0, "correct `r` value for second canvas.");
  is(pixel.g, 255, "correct `g` value for second canvas.");
  is(pixel.b, 255, "correct `b` value for second canvas.");
  is(pixel.a, 255, "correct `a` value for second canvas.");

  yield removeTab(target.tab);
  finish();
}