picogame: two dirty-rectangle fixes - #11290
Open
lynt-smitka wants to merge 2 commits into
Open
Conversation
Both layer kinds are documented and composited in screen coordinates: the draw path never applies the view offset to them. The dirty-rect pass applied it anyway to every non-fixed layer, so with a scrolled view a non-fixed StripDraw's invalidate() repainted an unrelated region while the layer's actual rectangle kept its stale pixels. A non-fixed Triangles batch similarly missed the band above/left of the view offset. Repro (device): StripDraw(cb, 100, 60, 40, 30, always_dirty=False) + scene.set_view(50, 20) + sd.invalidate() -> refresh() returned (150, 80, 190, 110) and the layer at (100, 60) never repainted.
A change wholly off-screen (the off-screen half of a wrapping parallax pair, a sprite parked outside) took a dirty slot anyway, and a scrolling background of wide strips burned two slots per strip - pushing a busy scene into the full-repaint overflow every frame. Clip to the screen first: fully invisible changes take no slot, partly visible ones are stored at their visible size, so the merge pass works on what actually gets repainted. Measured on a PicoPad (2026-08): the artifact-repro scene went from full repaints every frame to staying inside the 6-slot budget.
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
2 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
Two independent fixes in picogame's dirty-rectangle pass.
StripDrawandTriangleswere shifted by the scene view. Both composite in screen coordinates - the draw path never applies the view offset to them - but the dirty pass did, for every non-fixed layer. With a scrolled view,invalidate()repainted the wrong region and left the layer's own rectangle stale.Off-screen changes consumed dirty slots. A change entirely outside the screen took a slot anyway, and wide scrolling strips burned two slots each, so a busy scene fell back to a full repaint every frame. Rectangles are now clipped to the screen first: invisible changes take no slot, partly visible ones are stored at their visible size.