encounter/SDL
1
0
Fork 0
mirror of https://github.com/encounter/SDL.git synced 2025-12-13 23:26:18 +00:00
Code Issues Packages Projects Releases Wiki Activity

Fixed bug 4903 - Lack of color multiply with alpha (SDL_BLENDMODE_MOD + SDL_BLENDMODE_BLEND) blending mode for all renderers

Browse Source 
Konrad

This kind of blending is rather quite useful and in my opinion should be available for all renderers. I do need it myself, but since I didn't want to use a custom blending mode which is supported only by certain renderers (e.g. not in software which is quite important for me) I did write implementation of SDL_BLENDMODE_MUL for all renderers altogether.

SDL_BLENDMODE_MUL implements following equation:

dstRGB = (srcRGB * dstRGB) + (dstRGB * (1-srcA))
dstA = (srcA * dstA) + (dstA * (1-srcA))

Background:

https://i.imgur.com/UsYhydP.png

Blended texture:

https://i.imgur.com/0juXQcV.png

Result for SDL_BLENDMODE_MOD:

https://i.imgur.com/wgNSgUl.png

Result for SDL_BLENDMODE_MUL:

https://i.imgur.com/Veokzim.png

I think I did cover all possibilities within included patch, but I didn't write any tests for SDL_BLENDMODE_MUL, so it would be lovely if someone could do it.
This commit is contained in:
Sam Lantinga
2020-01-16 08:52:59 -08:00
parent 669729a8a0
commit 981e0d367c
19 changed files with 819 additions and 159 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
src/render/metal/SDL_render_metal.m
View File

@@ -357,6 +357,7 @@ MakePipelineCache(METAL_RenderData *data, METAL_PipelineCache *cache, const char
MakePipelineState(data, cache, @" (blend=blend)", SDL_BLENDMODE_BLEND);
MakePipelineState(data, cache, @" (blend=add)", SDL_BLENDMODE_ADD);
MakePipelineState(data, cache, @" (blend=mod)", SDL_BLENDMODE_MOD);
MakePipelineState(data, cache, @" (blend=mul)", SDL_BLENDMODE_MUL);
}
static void