"Color erase" mode doesn't work correctly for Bucket-fill and Blend tools.
GIMP version: 2.10.8
Operating System: Ubuntu 16.04
Package: Flatpack
Description of the bug
Create an image, with, from bottom to top
- A green (00FF00) background layer
- A layer with a blue (0000FF) background, on which a red (FF0000) circle has bee added (ellipse selection, filled). The red circle has smooth edges.
Reproduction
Is the bug reproducible? Always
Reproduction steps:
- Set the FG color to blue,
- With the Brush tool set to
Color erase
, paint over the edge of the circle. The edge is now red-on-green, but remains smooth because the blue in the anti-aliasing pixels has been replaced by transparency
- Set the Bucket-fill to
Color erase
and bucket-fill the layer. The blue disappear, but the pixels at the edge of the circle aren't changed, resulting in a jagged reddish rim over the green background (this is true ofDefault
andLegacy
mode).
- Rectangle-select a piece of the blue, and Bucket-dill with pattern instead of color: same bad result
- Set both FG and BG color to blue, and the Gradient to "FG to BG (RGB)"
- Set the Blend tool to
Color erase
. - Try to create a gradient. No sizeable part of the blue disappears. If you move the gradient endpoint, you can see green pixels blinking, so there is an attempt somewhere. Edit: managed to freeze with some pixels (at 4, 7, and 11 hours):
Expected result:
Actual result:
Additional information:
Color-to-alpha and the Color erase
blend mode of layers do work.