Re: [csswg-drafts] [css-shapes][css-images-3] `<radial-size>` syntax seems incorrect (#10812)

Hi @romainmenke @cdoublev, the main question was how to handle two independent <radial-extent> keywords in ellipse(), like:

[clip-path: ellipse(farthest-corner closest-corner at 175px 100px);](https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/external/wpt/css/css-masking/clip-path/clip-path-ellipse-closest-farthest-corner.html;l=19)

Chromium and WebKit parsers accept <shape-radius>{2}, where each radius resolves independently to the euclidean corner distance - no aspect ratio preservation. The above WPT test also uses this form.

My [CL](https://chromium-review.googlesource.com/c/chromium/src/+/7754379) implemented this based on the current parser behavior to make the WPT test pass, so I hadn't thought deeply about the spec's intent. But looking at the resulting ellipse, to me the current behavior doesn't seem to have a clear geometric meaning - the ellipse doesn't pass through any corner.

If we want an ellipse that passes through the specified corner and fits the box shape naturally, I feel updating the parser and the WPT test to match the spec could be a reasonable direction.

-- 
GitHub Notification of comment by hyowon-igalia
Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/10812#issuecomment-4285488054 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config

Received on Tuesday, 21 April 2026 02:10:43 UTC