806a633609
The use-case of this blend mode is to be able to make parts of an viewport overlay transparent. The future user of this blend mode is sequencer preview drawing where frame will be drawn to an HDR render frame-buffer, and overlays drawn on-top. In a way it is similar to the image engine, but without need to have custom shader. Ref #138094 Pull Request: https://projects.blender.org/blender/blender/pulls/138307