openlayers / openlayers/openlayers
Rendering issue with alpha transition
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- Dominant language
- JavaScript
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Description
The particle flow renderer in #14491 reveals an issue with alpha blending when the source is configured with a non-zero transition. The issue can be seeing by modifying the wind example to use transition: 100 and then zooming in.
I'm suspicious of code in the helper that enables blending but never disables it (but haven't dug enough to be sure this is the problem).
https://github.com/openlayers/openlayers/blob/121f2ee548e72bab8f33172a71054ca3805d7390/src/ol/webgl/Helper.js#L595-L596
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
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- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Reproduce the issue by modifying the wind example to use transition: 100 and zooming in. Start by inspecting src/ol/webgl/Helper.js around lines 595-596 and trace how blending is enabled for the particle flow renderer. Done means alpha rendering remains correct with a non-zero transition and blending state is handled correctly.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- javascript
- Domain
- computer-graphics
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 45/100