new UI clipping implementation#24148
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ickshonpe wants to merge 24 commits intobevyengine:mainfrom
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`CalculatedClip` is now an enum with `Rects` and `FullyClipped` variants. `Rects` holds a list of `Rect` in node local coords and `Affine2` world-to-local transform. `bevy_ui_render` has a new `clipping` module with a `clip_polygon` function that intersects UI elements with the clipping rects and chops off the non-visible regions and returns a list of vertices that forms a triangle fan. New example `overflow_transform`.
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| //! Demonstrates nested transformed UI clipping. | |||
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I think this probably belongs in testbed. It's a great test, but not very educational.
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Yeah maybe, I might expand it further though.
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kk! It's also fancy enough that I don't mind it being in the main examples.
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
…into overflow-transform
ickshonpe
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mnmaita
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May 6, 2026
…into overflow-transform
…into overflow-transform
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Objective
Get clipping working with transformed nodes.
Fixes #17630
Fixes #21775
(and probably quite a few others)
Solution
CalculatedClipis now an enum withRectsandFullyClippedvariants.Rectsholds a list ofRectin node local coords andAffine2world-to-local transform.bevy_ui_renderhas a newclippingmodule with aclip_polygonfunction that intersects UI elements with the clipping rects and chops off the non-visible regions and returns a list of vertices that forms a triangle fan. Uses a simplified version of the Sutherland–Hodgman algorithm.Performance isn't too bad, but text suffers a bit when clipped as there's no broad phase atm, instead it tests and breaks up each glyph individually. The clipping geometry also needs to be cached somewhere and updated incrementally.
I didn't try to optimise this branch too much yet as I suspect the required changes would probably end up being much larger and more complicated than the clipping implementation itself, and it might better to leave them for follow up PRs.
Testing
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