Re: [fxtf-drafts] Not all Filters Should Lead to Containing Blocks on All Fixed/Absolute Descendants (#402)

The problem is still present for color changes when the upper layers are not fully opaque, although the examples are not as dramatically different.  Consider this modified example where the front element is 50% opaque:

```html
<div style="background: black; width: 100px; height: 10px">
  <div style="background: rgba(255, 255, 0, 0.5); width: 100px; height: 10px; position: absolute"></div>
</div>
```

Here's what it looks like with the original, the correct filtered (with `hue-rotate(180deg)`) result, and the incorrect separately filtered result (see [source html](http://software.hixie.ch/utilities/js/live-dom-viewer/?%3C!DOCTYPE%20html%3E%0A%3Cstyle%3E%0A%0Abody%20%7B%20margin%3A%2050px%20%7D%0Abody%20%3E%20div%20%7B%20display%3A%20inline-block%3B%20margin-right%3A%2050px%3B%20%7D%0A.blur%20%7B%20filter%3A%20hue-rotate(180deg)%20%7D%0A%0A%3C%2Fstyle%3E%0A%0A%3Cdiv%20style%3D%22background%3A%20black%3B%20width%3A%20100px%3B%20height%3A%2010px%22%3E%0A%20%20%3Cdiv%20style%3D%22background%3A%20rgba(255%2C%20255%2C%200%2C%200.5)%3B%20width%3A%20100px%3B%20height%3A%2010px%3B%20position%3A%20absolute%22%3E%3C%2Fdiv%3E%0A%3C%2Fdiv%3E%0A%0A%3Cdiv%20style%3D%22background%3A%20black%3B%20width%3A%20100px%3B%20height%3A%2010px%22%20class%3D%22blur%22%3E%0A%20%20%3Cdiv%20style%3D%22background%3A%20rgba(255%2C%20255%2C%200%2C%200.5)%3B%20width%3A%20100px%3B%20height%3A%2010px%3B%20position%3A%20absolute%22%3E%3C%2Fdiv%3E%0A%3C%2Fdiv%3E%0A%0A%3Cdiv%20style%3D%22background%3A%20black%3B%20width%3A%20100px%3B%20height%3A%2010px%22%20class%3D%22blur%22%3E%3C%2Fdiv%3E%3Cdiv%20style%3D%22margin-left%3A%20-150px%3Bbackground%3A%20rgba(255%2C%20255%2C%200%2C%200.5)%3B%20width%3A%20100px%3B%20height%3A%2010px%22%20class%3D%22blur%22%3E%3C%2Fdiv%3E%0A)):

![Screenshot from 2020-07-05 12-59-40](https://user-images.githubusercontent.com/248721/86541148-78075980-bebf-11ea-91e1-99af4db1be54.png)

-- 
GitHub Notification of comment by dbaron
Please view or discuss this issue at https://github.com/w3c/fxtf-drafts/issues/402#issuecomment-653932416 using your GitHub account

Received on Sunday, 5 July 2020 20:01:14 UTC