Sprite to polygon conversion improvements
Created by: pouleyKetchoupp
I've mostly made some changes around the march square algorithm to fix errors and crashes when converting sprites to polygons, and added a few extra changes to make the tool easier to use.
List of changes:
- No reduced Rect in march square algorithm, it was causing inconsistent cases near the borders and made the outline less accurate
- Ignore invalid generated polygons (under 3 points) to avoid unnecessary errors and crashes
- Error popup only when no polygon could be generated at all
- Added option to shrink pixels (to get rid of small separate islands)
- Fixed polygon preview (lines were sometimes not showing along the borders)
Fixes #32564 (closed), fixes #29267 (closed)