The WGPU experiment

[veeenu]

I want to run a small, isolated experiment: build a wgpu renderer, check if it can be run in parallel to a game's renderer, and use BitBlt or similar to overlay the surface.

This would change the approach of hudhook to further reduce coupling, complexity, and maintainability effort: we could easily get rid of all the per-framework renderers, and get access to those for free when instantiating a hook.

Benefits

• Improves maintainability by getting rid of all the engine-specific renderers and allowing to only focus on the hooking functionality
• Improves the chance to maintain further hooks down the line
• Avoids messing with the game renderers' state
• Makes it easier to integrate new UI frameworks (looking at you, egui)
• Potential positive side effects on performance: by running the UI frame renderer in parallel to the game engine's renderer, the game's frame time stays unaffected

Drawbacks

• Potential negative side effects on performance: contention on GPU resources?

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If the experiment proves successful, I will keep the current "legacy" renderers as-is for 0.6.0, and then remove them in 0.7.0 once enough people have had the chance to test it.

[veeenu]

Something is almost working in this branch.

[veeenu]

Progress report: here's a small demo of a DirectX 12 renderer overlaid on top of Dark Souls III's DirectX 11 surface.

out.webm

Next attempt is trying this against different renderers -- DX9, OpenGL, Vulkan.
WGPU has proven a bit difficult to work with in regards to handling transparency, but I'll give it another shot.

[veeenu]

With no changes at all, the same library hooks successfully against a DirectX 12 game:

This suggests a method for detecting hook type could be feasible -- just using simple heuristics like check if a given DLL is loaded or not.

I am going to test against DX9 and OpenGL by replicating their hooks, and once I can confirm they work as well I will start a massive refactor.

[veeenu]

Dark Souls (DX9) is a go. Had to change the Dx12 device to use D3D_FEATURE_LEVEL_11_1 at creation, but with that value Dark Souls III and Elden Ring still work.

[veeenu]

A note: it is possible to block the game window from receiving messages by overlaying a transparent HWND on top of it, and selectively altering its WS_EX_TRANSPARENT state. This could solve #79 finally

[veeenu]

OpenGL confirmed! We can now support all existing renderers, and adding new ones is going to be almost trivial.

[veeenu]

#143 implements this (though a DirectX12 renderer and not a WGPU renderer).