<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Font-relative lengths on an operator</title>
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<link rel="help" href="https://w3c.github.io/mathml-core/#dictionary-based-attributes">
<link rel="help" href="https://w3c.github.io/mathml-core/#embellished-operators">
<link rel="help" href="https://w3c.github.io/mathml-core/#definition-of-space-like-elements">
<link rel="help" href="https://w3c.github.io/mathml-core/#layout-of-mrow">
<meta name="assert" content="Verify font-relative lengths refer to the core operator, not the embellished operator">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/mathml/support/fonts.js"></script>
<style>
  math {
      font: 100px/1 Ahem;
  }
  @font-face {
      font-family: operators;
      src: url("/fonts/math/operators.woff");
  }
  mo {
      font-family: operators;
  }
</style>
<script>
  setup({ explicit_done: true });
  window.addEventListener("load", () => { loadAllFonts().then(runTests); });

  function runTests() {
      var epsilon = 1;
      var baseSizePx = 100;

      test(function() {
          var beforeRight = document.getElementById("before1").getBoundingClientRect().right;
          var afterLeft = document.getElementById("after1").getBoundingClientRect().left;
          var fontScalePercent = .5;
          var lspaceEm = 1;
          var moWidthEm = 1;
          assert_approx_equals(afterLeft - beforeRight, baseSizePx * fontScalePercent * (lspaceEm + moWidthEm), epsilon, "baseSizePx * fontScalePercent * lspaceEm");
      }, `font-relative lspace refers to the core operator`);

      test(function() {
          var beforeRight = document.getElementById("before2").getBoundingClientRect().right;
          var afterLeft = document.getElementById("after2").getBoundingClientRect().left;
          var fontScalePercent = 2;
          var rspaceEm = 1;
          var moWidthEm = 1;
          assert_approx_equals(afterLeft - beforeRight, baseSizePx * fontScalePercent * (rspaceEm + moWidthEm), epsilon, "baseSizePx * fontScalePercent * rspaceEm");
      }, `font-relative rspace refers to the core operator`);

      test(function() {
          var moStretchSize = document.getElementById("operator1").getBoundingClientRect().height;
          var fontScalePercent = .5;
          var minsizeEm = 8;
          var beforeHeight = document.getElementById("before1").getBoundingClientRect().height;

          assert_approx_equals(moStretchSize, baseSizePx * minsizeEm * fontScalePercent, epsilon, "baseSizePx * fontScalePercent * minsizeEm");

          // This is really testing the same thing but do make sure minsize is
          // applied i.e. the unconstrained target size is less than the actual
          // stretch size.
          assert_approx_equals(beforeHeight, moStretchSize / 2, epsilon);

      }, `font-relative minsize refers to the core operator`);

      test(function() {
          var moStretchSize = document.getElementById("operator2").getBoundingClientRect().height;
          var fontScalePercent = 2;
          var maxsizeEm = 1;
          var afterHeight = document.getElementById("after2").getBoundingClientRect().height;

          assert_approx_equals(moStretchSize, baseSizePx * maxsizeEm * fontScalePercent, epsilon, "baseSizePx * fontScalePercent * maxsizeEm");

          // This is really testing the same thing but do make sure maxsize is
          // applied i.e. the unconstrained target size is more than the actual
          // stretch size.
          assert_approx_equals(afterHeight, 2 * moStretchSize, epsilon);

      }, `font-relative maxsize refers to the core operator`);

      done();
  }
</script>
</head>
<body>
  <div id="log"></div>
  <p>
    <math>
      <mrow>
        <mspace id="before1" width="1em" height="1em" depth="1em" style="background: blue"/>
        <mrow style="font-size: 50%;">
          <mo id="operator1" lspace="1em" rspace="0em" minsize="8em">⥯</mo>
          <mspace id="after1" width="1em" height=".5em" depth=".5em" style="background: green"/>
        </mrow>
        <mn><!-- not space like --></mn>
      </mrow>
    </math>
  </p>
  <p>
    <math>
      <mrow>
        <mrow style="font-size: 200%">
          <mspace id="before2" width="1em" height=".5em" depth=".5em" style="background: green"/>
          <mo id="operator2" lspace="0em" rspace="1em" maxsize="1em">⥯</mo>
        </mrow>
        <mspace id="after2" width="1em" height="2em" depth="2em" style="background: blue"/>
        <mn><!-- not space like --></mn>
      </mrow>
    </math>
  </p>
</body>
</html>
