2d.transformation.rotate.wrap.html

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This WPT test may be referenced by the following Test IDs:
- /html/canvas/offscreen/transformations/2d.transformation.rotate.wrap.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.transformation.rotate.wrap</title>

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

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

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

<h1>2d.transformation.rotate.wrap</h1>

<p class="desc">rotate() wraps large positive values correctly</p>

<script>

var t = async_test("rotate() wraps large positive values correctly");

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 = '#f00';

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

  ctx.rotate(Math.PI * (1 + 4096)); // == pi (mod 2*pi)

  // We need about pi +/- 0.001 in order to get correct-looking results

  // 32-bit floats can store pi*4097 with precision 2^-10, so that should

  // be safe enough on reasonable implementations

  ctx.fillStyle = '#0f0';

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

  _assertPixel(canvas, 50,25, 0,255,0,255);

  _assertPixel(canvas, 98,2, 0,255,0,255);

  _assertPixel(canvas, 98,47, 0,255,0,255);

  t.done();

});

</script>