2d.imageData.get.source.negative.html

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

<!DOCTYPE html>

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

<title>OffscreenCanvas test: 2d.imageData.get.source.negative</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.get.source.negative</h1>

<p class="desc">getImageData() works with negative width and height, and returns top-to-bottom left-to-right</p>

<script>

var t = async_test("getImageData() works with negative width and height, and returns top-to-bottom left-to-right");

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');

  ctx.fillStyle = '#000';

  ctx.fillRect(0, 0, 100, 50);

  ctx.fillStyle = '#fff';

  ctx.fillRect(20, 10, 60, 10);

  var imgdata1 = ctx.getImageData(85, 25, -10, -10);

  _assertSame(imgdata1.data[0], 255, "imgdata1.data[\""+(0)+"\"]", "255");

  _assertSame(imgdata1.data[1], 255, "imgdata1.data[\""+(1)+"\"]", "255");

  _assertSame(imgdata1.data[2], 255, "imgdata1.data[\""+(2)+"\"]", "255");

  _assertSame(imgdata1.data[3], 255, "imgdata1.data[\""+(3)+"\"]", "255");

  _assertSame(imgdata1.data[imgdata1.data.length-4+0], 0, "imgdata1.data[imgdata1.data.length-4+0]", "0");

  _assertSame(imgdata1.data[imgdata1.data.length-4+1], 0, "imgdata1.data[imgdata1.data.length-4+1]", "0");

  _assertSame(imgdata1.data[imgdata1.data.length-4+2], 0, "imgdata1.data[imgdata1.data.length-4+2]", "0");

  _assertSame(imgdata1.data[imgdata1.data.length-4+3], 255, "imgdata1.data[imgdata1.data.length-4+3]", "255");

  var imgdata2 = ctx.getImageData(0, 0, -1, -1);

  _assertSame(imgdata2.data[0], 0, "imgdata2.data[\""+(0)+"\"]", "0");

  _assertSame(imgdata2.data[1], 0, "imgdata2.data[\""+(1)+"\"]", "0");

  _assertSame(imgdata2.data[2], 0, "imgdata2.data[\""+(2)+"\"]", "0");

  _assertSame(imgdata2.data[3], 0, "imgdata2.data[\""+(3)+"\"]", "0");

  t.done();

});

</script>