Rect2 * Transform2D broken in 3.x LTS for C#

[andy-noisyduck]

Tested versions

Reproducible in 3.x. Fixed in 4.x.

System information

Godot 3.5 Mono

Issue description

Multiplying a Rect2 by a transform gives incorrect results (see example steps). The inverse is also incorrect.

Looks like this was introduced by #52666 with the 3.x backport #52762. Master waster later fixed by #64729, but this fix was never backported.

I note the comment by aaronfranke about sneaking the fix into the PR for 4.x rather than a separate PR (#64729 (comment)) 👀

Steps to reproduce

var r = new Rect2(0, 0, 100, 100);
var foo = r * new Transform2D( 1, 0, 0, 1, 0, 0);  // = ((0, 0), (100, 100)) - OK
var bar = r * new Transform2D(-1, 0, 0, 1, 0, 0);  // = ((-100, 0), (200, 100)) - Incorrect

Minimal reproduction project (MRP)

N/A

[raulsntos]

Thanks for the detailed report. Since you've already tracked down the cause of the issue, are you interested in submitting a PR with the fix? It's fine if you can't or don't want to, someone else can do it, I just want to make sure that I don't step on your toes.

[andy-noisyduck]

Thanks for the detailed report. Since you've already tracked down the cause of the issue, are you interested in submitting a PR with the fix? It's fine if you can't or don't want to, someone else can do it, I just want to make sure that I don't step on your toes.

I can make a PR. It's just a one-line fix for both the operators. I've not done a backport - should I just target the current 3.5 branch with the PR?

[raulsntos]

For Godot 3 PRs target the 3.x branch.

[akien-mga]

Fixed by #86466.