[read-fonts] revert midpoint change to match FT #1294
Merged
Conversation
This file contains 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
A recent PR to fix an overflow changed the midpoint calculation from `(a + b) / 2` to the "equivalent" `a + (b - a) / 2` to attempt to avoid overflow with large values but this ends up producing results that don't exactly match FreeType in some cases. This just changes the expression to `a.wrapping_add(b) / 2` to restore compatibility while still avoiding the panic on overflow.
drott
approved these changes
Dec 20, 2024
|
Will add: "The results differ when |
This was e7161e7 in 0.26.2 - which I was starting to roll in Chromium but eventually did not land yet. https://chromium-review.googlesource.com/c/chromium/src/+/6088164 - it would be good to have this fix in a release, together with the fix for #1295 - then we need to update the roll into Chromium. I hope I get to it before the branch point (even though I am OOO). |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
A recent PR to fix an overflow changed the midpoint calculation from
(a + b) / 2to the "equivalent"a + (b - a) / 2to attempt to avoid overflow with large values but this ends up producing results that don't exactly match FreeType in some cases.This just changes the expression to
a.wrapping_add(b) / 2to restore compatibility while still avoiding the panic on overflow.