User-defined shaders

[CyberShadow]

Hi, thank you for this project.

I'm wondering if this project could have something equivalent to picom's window-shader-fg-rule, which allows specifying a user-supplied GLSL file to use for windows matching user-defined rules.

Such a feature would allow achieving e.g. the following:

• Smart color inversion (for applications not supporting a "dark mode")
• Color-key based transparency (for applications without native transparency support)
• Ad-hoc hacks / accessibility improvements (adding guides/crosshairs, color correction for color blindness)

Upstream issue (closed WONTFIX): swaywm/sway#3652

[WillPower3309]

This should be relatively easy to implement, and I'd accept any PRs implementing this

[WillPower3309]

For more context, we could implement this with an initial rendering pass that applies the user defined shader prior to our shaders

[xplshn]

Maybe, need to investigate how modular Vulkan shaders are, and how this would interact with a potential migration to compute shaders.

Why not use "slang"?

Arguments in favor of slang would be:

• Slang is backwards-compatible with most existing HLSL code. It is possible to start taking advantage of Slang's benefits without rewriting or porting your shader codebase.
• The Slang compiler can generate code for a wide variety of targets and APIs: D3D12, Vulkan, D3D11, OpenGL, CUDA, and CPU. Slang code can be broadly portable, but still take advantage of the unique features of each platform.
• And lots more that aren't related to Slang's compatibility with platforms but rather the language itself

[WillPower3309]

dependent on wlrfx/scenefx#53