<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Fraction</title>
<link rel="help" href="https://w3c.github.io/mathml-core/#fractions-mfrac">
<link rel="help" href="https://w3c.github.io/mathml-core/#fraction-with-nonzero-line-thickness">
<link rel="help" href="https://w3c.github.io/mathml-core/#fraction-with-zero-line-thickness">
<meta name="assert" content="Verify fraction metrics for different sizes of numerator and denominator.">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/mathml/support/feature-detection.js"></script>
<script src="/mathml/support/fonts.js"></script>
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css" />
<style>
math, mspace {
/* OS/2.sxHeight = 800 */
/* post.underlineThickness == 20 */
font-family: Ahem;
font-size: 10px;
}
div.shrink-wrap {
background: yellow;
display: inline-block;
margin-top: 5px;
padding-top: 5px;
}
</style>
<script>
const xHeight = 800;
const underlineThickness = 800;
const emToPx = 10 / 1000; // font-size: 10px, font.em = 1000
function getBox(aId) {
var box = document.getElementById(aId).getBoundingClientRect();
box.middle = (box.bottom + box.top) / 2;
box.center = (box.left + box.right) / 2;
return box;
}
setup({ explicit_done: true });
window.addEventListener("load", () => { loadAllFonts().then(runTests); });
function runTests() {
test(function() {
assert_true(MathMLFeatureDetection.has_mspace());
var e = 4;
var mathAxis = getBox("baseline").top - (xHeight/2) * emToPx;
for (var i = 0; i <= 4; i++) {
var frac = getBox("frac" + i);
var num = getBox("frac" + i + "num");
var den = getBox("frac" + i + "den");
// To estimate the fraction axis, we calculate barycenter between the
// top and bottom of the fraction, using the heights of numerator and
// denominator as weights.
var fracAxis = (frac.top * den.height + frac.bottom * num.height) / (num.height + den.height);
assert_approx_equals(fracAxis, mathAxis, e, "frac" + i + " fraction bar");
}
}, "Fraction axis is aligned on the math axis");
test(function() {
assert_true(MathMLFeatureDetection.has_mspace());
for (var i = 0; i < 10; i++) {
assert_less_than_equal(getBox("frac" + i + "num").bottom, getBox("frac" + i + "den").top, "numerator is above denominator");
assert_less_than(getBox("frac" + i + "den").top - getBox("frac" + i + "num").bottom, 5, "The gap between numerator and denominator is not too large");
}
}, "Vertical positions of numerator and denominator");
test(function() {
assert_true(MathMLFeatureDetection.has_mspace());
var e = 3;
for (var i = 0; i < 10; i++)
assert_approx_equals(getBox("frac" + i + "num").center, getBox("frac" + i + "den").center, e, "numerator and denominator are horizontally centered");
}, "Horizontal alignments of numerator and denominator");
test(function() {
assert_true(MathMLFeatureDetection.has_mspace());
var e = 5;
for (var i = 0; i < 10; i++) {
var frac = getBox("frac" + i);
var num = getBox("frac" + i + "num");
var den = getBox("frac" + i + "den");
assert_approx_equals(frac.height, den.bottom - num.top, e, "height of frac " + i + " is determined by the bottom/top sides of the denominator/numerator");
assert_approx_equals(frac.width, Math.max(num.right, den.right) - Math.min(num.left, den.left), e, "width of frac " + i + " is determined by the left/right sides of the denominator/numerator (plus some spacing)");
}
}, "Dimension of mfrac elements");
test(function() {
assert_true(MathMLFeatureDetection.has_mspace());
assert_true(MathMLFeatureDetection.has_mfrac());
Array.from(document.getElementsByClassName("shrink-wrap")).forEach((container) => {
var marginPx = 2; // By default fractions have 1px margin on each side.
var epsilon = 1;
var containerWidth = container.getBoundingClientRect().width;
var children = container.getElementsByTagName("mspace");
var numWidth = children[0].getBoundingClientRect().width;
var denWidth = children[1].getBoundingClientRect().width;
assert_approx_equals(containerWidth, marginPx + Math.max(numWidth, denWidth), epsilon, "Should be the maximum preferred width of numerator/denominator.");
});
}, "Preferred width of mfrac elements");
done();
}
</script>
</head>
<body>
<div id="log"></div>
<p>
<math>
<mspace id="baseline" width="1em" height="0em" depth="1em" style="background: black"/>
<mfrac id="frac0">
<mspace id="frac0num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac0den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac1">
<mspace id="frac1num" width="30px" height="15px" style="background: blue"/>
<mspace id="frac1den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac2">
<mspace id="frac2num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac2den" width="30px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac3">
<mspace id="frac3num" width="15px" height="30px" style="background: blue"/>
<mspace id="frac3den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac4">
<mspace id="frac4num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac4den" width="15px" height="30px" style="background: green"/>
</mfrac>
<mfrac id="frac5" linethickness="0px">
<mspace id="frac5num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac5den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac6" linethickness="0px">
<mspace id="frac6num" width="30px" height="15px" style="background: blue"/>
<mspace id="frac6den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac7" linethickness="0px">
<mspace id="frac7num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac7den" width="30px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac8" linethickness="0px">
<mspace id="frac8num" width="15px" height="30px" style="background: blue"/>
<mspace id="frac8den" width="15px" height="15px" style="background: green"/>
</mfrac>
<mfrac id="frac9" linethickness="0px">
<mspace id="frac9num" width="15px" height="15px" style="background: blue"/>
<mspace id="frac9den" width="15px" height="30px" style="background: green"/>
</mfrac>
</math>
</p>
<div class="shrink-wrap">
<math>
<mfrac>
<mspace width="30px" height="15px" style="background: blue"/>
<mspace width="15px" height="15px" style="background: green"/>
</mfrac>
</math>
</div>
<div class="shrink-wrap">
<math>
<mfrac>
<mspace width="15px" height="15px" style="background: blue"/>
<mspace width="30px" height="15px" style="background: green"/>
</mfrac>
</math>
</div>
<div class="shrink-wrap">
<math>
<mfrac linethickness="0px">
<mspace width="30px" height="15px" style="background: blue"/>
<mspace width="15px" height="15px" style="background: green"/>
</mfrac>
</math>
</div>
<div class="shrink-wrap">
<math>
<mfrac linethickness="0px">
<mspace width="15px" height="15px" style="background: blue"/>
<mspace width="30px" height="15px" style="background: green"/>
</mfrac>
</math>
</div>
</body>
</html>
Codebase Browser
chromium