2d.state.saverestore.imageSmoothingEnabled.html

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This WPT test may be referenced by the following Test IDs:
- /html/canvas/element/manual/the-canvas-state/2d.state.saverestore.imageSmoothingEnabled.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<meta charset="utf-8">

<title>CanvasRenderingContext2D imageSmoothingEnabled save/restore test</title>

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

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

<link rel="help" href="https://html.spec.whatwg.org/multipage/scripting.html#image-smoothing">

<script>

function createTestImage() {

  var image = document.createElement('canvas');

  var imgctx = image.getContext('2d');

  imgctx.fillStyle = "#F00";

  imgctx.fillRect(0, 0, 2, 2);

  imgctx.fillStyle = "#0F0";

  imgctx.fillRect(0, 0, 1, 1);

  return image;

test(function() {

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

  ctx.save();

  ctx.imageSmoothingEnabled = false;

  ctx.restore();

  assert_equals(ctx.imageSmoothingEnabled, true);

}, "Test that restore() undoes any modifications to imageSmoothingEnabled.");

test(function() {

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

  ctx.imageSmoothingEnabled = false;

  var old = ctx.imageSmoothingEnabled;

  ctx.save();

  assert_equals(ctx.imageSmoothingEnabled, old);

  ctx.restore();

}, "Test that save() doesn't modify the values of imageSmoothingEnabled.");

test(function() {

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

  ctx.imageSmoothingEnabled = false;

  ctx.save();

  ctx.imageSmoothingEnabled = true;

  ctx.restore();

  var image = createTestImage();

  ctx.scale(10, 10);

  ctx.drawImage(image, 0, 0);

  var pixels = ctx.getImageData(0, 0, 1, 1).data;

  assert_array_equals(pixels, [0, 255, 0, 255]);

}, "Test that restoring actually changes smoothing and not just the attribute value.");

</script>