2d.text.measure.index-from-offset-edge-cases.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/offscreen/text/2d.text.measure.index-from-offset-edge-cases.tentative.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.text.measure.index-from-offset-edge-cases.tentative</title>

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

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

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

<h1>2d.text.measure.index-from-offset-edge-cases.tentative</h1>

<p class="desc">Test the edge cases for getIndexFromOffset, where the point is at the edge of glyph and at the midpoint.</p>

<script>

promise_test(async t => {

  var canvas = new OffscreenCanvas(100, 50);

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

  var f = new FontFace("CanvasTest", "url('/fonts/CanvasTest.ttf')");

  f.load();

  document.fonts.add(f);

  await document.fonts.ready;

  ctx.font = '50px CanvasTest';

  ctx.direction = 'ltr';

  ctx.align = 'left'

  ctx.baseline = 'alphabetic'

  tm = ctx.measureText('A');

  const a_width = tm.width;

  tm = ctx.measureText('B');

  const b_width = tm.width;

  tm = ctx.measureText('C');

  const c_width = tm.width;

  const epsilon = 1.0e-4;

  tm = ctx.measureText('ABC');

  _assert(tm.getIndexFromOffset(0) == 0, "tm.getIndexFromOffset(0) == 0");

  _assert(tm.getIndexFromOffset(a_width / 2) == 0, "tm.getIndexFromOffset(a_width / 2) == 0");

  _assert(tm.getIndexFromOffset(a_width / 2 + 1) == 1, "tm.getIndexFromOffset(a_width / 2 + 1) == 1");

  _assert(tm.getIndexFromOffset(a_width) == 1, "tm.getIndexFromOffset(a_width) == 1");

  _assert(tm.getIndexFromOffset(a_width + b_width / 2) == 1, "tm.getIndexFromOffset(a_width + b_width / 2) == 1");

  _assert(tm.getIndexFromOffset(a_width + b_width / 2 + 1) == 2, "tm.getIndexFromOffset(a_width + b_width / 2 + 1) == 2");

  _assert(tm.getIndexFromOffset(a_width + b_width) == 2, "tm.getIndexFromOffset(a_width + b_width) == 2");

  _assert(tm.getIndexFromOffset(a_width + b_width + c_width / 2) == 2, "tm.getIndexFromOffset(a_width + b_width + c_width / 2) == 2");

  _assert(tm.getIndexFromOffset(a_width + b_width + c_width / 2 + 1) == 3, "tm.getIndexFromOffset(a_width + b_width + c_width / 2 + 1) == 3");

  _assert(tm.getIndexFromOffset(a_width + b_width + c_width) == 3, "tm.getIndexFromOffset(a_width + b_width + c_width) == 3");

}, "Test the edge cases for getIndexFromOffset, where the point is at the edge of glyph and at the midpoint.");

</script>