Transparent colours Brush

Can we please have an option to “lock in” the brush transparency when it is grabbed, thereby freeing us to change the BG colour and make the Brush FG<>BG mechanic usable again?

Background:

Brush transparency used to be consistent and simple to understand in 4.7 which behaved like DPaint.

Since 6.5, grabbing a brush with a transparent color, then changing the BG color changes the transparent color in really weird and inconsistent ways. None of the grab brush options seem to make much of a difference. Grabbing a brush and setting the background color to a color used in the brush, adds that new BG color to the transparency, do this a few times on a graphic intended for 8 or 16-bit hardware and you can completely wipe the graphic.

This completely messes up FB<>BG functionality. A feature I’ve used since Amiga DPaint to remap a single color on part of an image or a sprite. Sometimes as a way of quickly and intuitively changing all the colors of a set of sprites without having to set up another image or project and mess around with stencils.

Weirdly, Grabbing a brush with secondary color used as transparency produces a weird result when FG<>BG is used, yet if you reset the brush using Shit B, then do FG<>BG again it works as expected. Unfortunately this only works once if you wanted to repeatedly uses FB<>BG to change more than one color as it resets the brush to the one grabbed.

All this makes me think that this is indeed a bug as I can’t understand why such behavior would be by design.

When I pick up a brush and have “Second Color” (=BG color) defined as Transparency Mode then this color entry becomes transparent.
You said that later changing the BG color now also changes the transparent color of the brush. I can’t duplicate this.

I think I miss something. Changing the BG color should never touch the current brush’s transparent color setting. If it does then it’s a bug and I need to make it show in order to solve it.

Yes I can confirm this happens.

However, it has just occurred to me, after unsuccessfully trying to record screen output, that this might be a windows 7 thing.

Either way, the following four images show what happens.
In all the images- the brush is only picked once and i “hover” it so it crosses the red square. I change the background colour twice (if I changed the background colour again to drk grey the sprite wouldn’t be visible)
Image 2, has colour index 0 (black) as BGcol. Image 3 has colour index 1 as BG and now the white AND the black are transparent.

(naturally this makes using BrushFG<->BrushBG rather hard to use)

Can duplicate it! It happens when you use the right mouse button in the color palette window to select the second color. It does not happen if you click on the second color swatch at the top left of the main window. Will check and fix.

I think I fixed it. I plan to publish a small hotfix next week if everything goes well.