subpixel-offset-scaled-transform-composited.html

<!DOCTYPE html>
<style>
.container { position: relative; width: 0; height: 0; }
/* Not using will-change: transform because it ignores subpixel accumulation. */
.composited { will-change: opacity; }
.scale { transform-origin: 0 0; transform: scale(40); }
.child { width: 1px; height: 1px; background: blue; position: relative; left: 0.4px }
</style>
<div id="container1" class="container scale">
  <div id="child1" class="child composited"></div>
</div>
<div id="container2" class="container" style="top: 50px">
  <div id="child2" class="child scale composited"></div>
</div>
<div id="container3" class="container scale composited" style="top: 100px">
  <div id="child3" class="child"></div>
</div>
<div id="container4" class="container composited" style="top: 150px">
  <div id="child4" class="child scale"></div>
</div>
<div id="container5" class="container scale composited" style="top: 200px">
  <div id="child5" class="child composited"></div>
</div>
<div id="container6" class="container composited" style="top: 250px">
  <div id="child6" class="child scale composited"></div>
</div>
<script src="../resources/text-based-repaint.js"></script>
<script>
function repaintTest() {
  for (var container of document.getElementsByClassName('container'))
    container.style.left = '0.3px';
}
onload = runRepaintAndPixelTest;
</script>

chromium/third_party/blink/web_tests/paint/invalidation/compositing/subpixel-offset-scaled-transform-composited.html