2d.imageData.create2.large.html

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This WPT test may be referenced by the following Test IDs:
- /html/canvas/offscreen/pixel-manipulation/2d.imageData.create2.large.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->

<meta charset="UTF-8">

<title>OffscreenCanvas test: 2d.imageData.create2.large</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<script src="/html/canvas/resources/canvas-tests.js"></script>

<h1>2d.imageData.create2.large</h1>

<p class="desc">createImageData(sw, sh) works for sizes much larger than the canvas</p>

<script>

var t = async_test("createImageData(sw, sh) works for sizes much larger than the canvas");

var t_pass = t.done.bind(t);

var t_fail = t.step_func(function(reason) {

    throw reason;

});

t.step(function() {

  var canvas = new OffscreenCanvas(100, 50);

  var ctx = canvas.getContext('2d');

  var imgdata = ctx.createImageData(1000, 2000);

  _assertSame(imgdata.data.length, imgdata.width*imgdata.height*4, "imgdata.data.length", "imgdata.width*imgdata.height*4");

  _assert(imgdata.width < imgdata.height, "imgdata.width < imgdata.height");

  _assert(imgdata.width > 0, "imgdata.width > 0");

  var isTransparentBlack = true;

  for (var i = 0; i < imgdata.data.length; i += 7813) // check ~1024 points (assuming normal scaling)

      if (imgdata.data[i] !== 0)

          isTransparentBlack = false;

  _assert(isTransparentBlack, "isTransparentBlack");

  t.done();

});

</script>