backdrop-filter-basic-opacity-2.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>backdrop-filter: Basic operation of filter with opacity</title>
<link rel="author" href="mailto:[email protected]">
<link rel="help" href="https://drafts.fxtf.org/filter-effects-2/#BackdropFilterProperty">
<link rel="match"  href="backdrop-filter-basic-opacity-2-ref.html">

<div>
  <p>Expected: Just a single grey box.</p>
</div>
<div class="box colorbox"></div>
<div class="box filterbox"></div>

<style>
.box {
    position: absolute;
    width: 100px;
    height: 100px;
    left: 10px;
    top: 100px;
}
.colorbox {
    background: green;
}
.filterbox {
    backdrop-filter: invert(1);
    opacity: 0.5;
    /* An invert backdrop-filter with opacity 0.5 should always give a grey
       result. It will always mix the background color with its inverse, in
       equal proportion.*/
}
</style>

chromium/third_party/blink/web_tests/external/wpt/css/filter-effects/backdrop-filter-basic-opacity-2.html