fix(canvas): detect non-scaleX transforms and honor shader value cache#122
Merged
Conversation
Two correctness bugs in the Canvas2D backend: - addQuad detected a transform only when ta !== 1, so scaleY-only, rotation, and skew transforms with scaleX === 1 were silently dropped and the node drew untransformed. Check all four matrix components. - CanvasShaderNode.update assigned cached shader values on a value-key hit but fell through to recompute anyway, making the canvas shader value cache dead code. Add the missing early return, matching WebGlShaderNode.update. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Fixes the two correctness bugs from the Canvas2D hot-path review (
docs/canvas-renderer-review.md, items 1 and 2):addQuadmissed scaleY-only transforms.hasTransformchecked onlyta !== 1, so any transform withscaleX === 1— scaleY-only, rotation, skew — was silently dropped and the node drew untransformed. Now checks all four matrix components:ta !== 1 || td !== 1 || tb !== 0 || tc !== 0.CanvasShaderNode.updatenever used its value cache. On a shader-value-cache hit it assignedthis.computed = computedand then unconditionally fell through to recompute, allocate a fresh computed object, and re-register the key. Added the missing earlyreturn, matchingWebGlShaderNode.update. Cache hits now skip the recompute and allocation.Tests
addQuadtransform-detection cases (scaleY-only, rotation-only, identity skip) inCanvasRenderer.test.tsCanvasShaderNode.test.tscovering cache miss, cache hit, and unchanged-key paths🤖 Generated with Claude Code