I realize I might be one of the few developers that care about custom
shader support in terminal but I thought it's worth proposing it and see
what you think.
This is to support custom shaders with custom textures.
I was thinking of exposing the background image to the shader but that
felt complicated after looking into it.
I have tested exploratively. I think the texture loader is possible to
unit test so that is a possible improvement.
The error reporting (as with other custom pixel shader code) is not very
good. That is also an area that I could improve upon.
I do think the risk of adding this is rather low as the new code is only
executed when experimental.pixelShaderImagePath is set.
### Details
Only added to the Atlas engine.
Instead I load the texture using WIC into a shader resource view. When
binding shader resources I test for presence of custom texture and bind
it to register t1.
The image loading code was found in [the D3D Texture documentation].
It's a mouthful but seems rather robust.
Tested setting: "experimental.pixelShaderImagePath"
1. Tested not specifying it.
2. Tested setting it.
3. Tested changing it (the changes are picked up)
4. Tested invalid path
5. Tested a custom shader that made use of the custom texture.
[the D3D Texture documentation]: https://learn.microsoft.com/en-us/windows/win32/direct3d11/overviews-direct3d-11-resources-textures-how-to
Co-authored-by: Mike Griese <migrie@microsoft.com>
Co-authored-by: Leonard Hecker <lhecker@microsoft.com>
