draw-element-image-get-image-data.tentative.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /html/canvas/element/manual/draw-element-image/draw-element-image-get-image-data.tentative.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<title>drawElementImage should not taint the canvas</title>

<link rel="help" href="https://github.com/WICG/html-in-canvas">

<link rel="author" href="mailto:vmpstr@chromium.org">

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

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

<script src="/html/canvas/resources/wait-for-canvas-paint.js"></script>

<style>

#child {

  width: 100px;

  height: 100px;

  background: #01ff02;

</style>

<canvas id=canvas width="200" height="200" layoutsubtree>

  <div id=child></div>

</canvas>

<script>

  promise_test(async () => {

    await waitForCanvasPaint(canvas);

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

    ctx.fillStyle = 'rgb(3, 4, 5)';

    ctx.fillRect(0, 0, 200, 200);

    ctx.drawElementImage(child, 20, 30);

    const image_data = ctx.getImageData(19, 35, 2, 1);

    assert_equals(image_data.width, 2);

    assert_equals(image_data.height, 1);

    const data = image_data.data;

    // The background pixel.

    assert_equals(data[0], 3);

    assert_equals(data[1], 4);

    assert_equals(data[2], 5);

    assert_equals(data[3], 255);

    // The drawn element pixel.

    assert_equals(data[4], 1);

    assert_equals(data[5], 255);

    assert_equals(data[6], 2);

    assert_equals(data[7], 255);

  }, 'canvas drawElementImage readback');

</script>