<!DOCTYPE html>
<title>Tests that the ascentOverride, descentOverride and lineGapOverride attributes of FontFace work</title>
<link rel="help" href="https://drafts.csswg.org/css-font-loading/#fontface-interface">
<link rel="help" href="https://drafts.csswg.org/css-fonts-4/#font-metrics-override-desc">
<link rel="match" href="fontface-override-descriptors-ref.html">
<script>
const face = new FontFace(
'Ahem',
'local("Ahem"), url("/fonts/Ahem.ttf")',
{ascentOverride: '100%', descentOverride: '100%', lineGapOverride: '100%'});
document.fonts.add(face);
// Line height is ascent + descent + lineGap = 3em
// Baseline is placed at lineGap * 0.5 + ascent = 1.5em below line box top
// Since each Ahem 'X' glyph has 0.8em above baseline, the top of each glyph
// should be placed at 0.7em below line box top
</script>
<style>
#target {
position: absolute;
font-family: Ahem;
font-size: 20px;
}
</style>
<div id="target">
XXXXX<br>
XXXXX
</div>