WebGPUTextureUtils: Fix readback buffer size. #31765
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📦 Bundle sizeFull ESM build, minified and gzipped.
🌳 Bundle size after tree-shakingMinimal build including a renderer, camera, empty scene, and dependencies.
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mrdoob
reviewed
Aug 28, 2025
| const readBuffer = device.createBuffer( | ||
| { | ||
| size: width * height * bytesPerTexel, | ||
| size: ( height - 1 ) * bytesPerRow + width * bytesPerTexel, // see https://github.com/mrdoob/three.js/issues/31658#issuecomment-3229442010 |
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Is this more readable?
( width * bytesPerTexel ) + ( ( height - 1 ) * bytesPerRow )
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IMO, the "( height - 1 ) * bytesPerRow" bit should come first since "( width * bytesPerTexel )" represents the last row of data.
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Then this?
( height - 1 ) * bytesPerRow + ( width * bytesPerTexel )Or even this?
( ( height - 1 ) * bytesPerRow ) + ( width * bytesPerTexel )
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I vote for the last one!
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Updated: 6c7d807
Definitely improves code clarity 👍 .
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Thanks @greggman! |
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Fixed #31658.
Description
Turns out we have a bug in our readback buffer size computation in the WebGPU backend. We must honor the row padding in the buffer computation except for the last row. Credits to @greggman who explained the fix at the Chromium bug tracker and here: #31658 (comment) 🙌 !