Enforce presence of all fragment shader inputs in Veldrid

[frenzibyte]

• Reverts 53272d8 in favour of this PR
• Can also revert Add isolated vertex shader for logo animation osu-resources#249 & Use custom vertex shader for logo animation osu#22883

This works around D3D11 not working on shaders that don't make use of all members in the fragment input / vertex output. It seems D3D11 naturally expects all vertex output members are used in the fragment shader, and its optimisation of culling out unused fragment input members seems to affect the vertex output / fragment input structure.

One solution was to design localised vertex structures that match the needs of the fragment shader, but that turned out to be not pretty as time went and more shaders required this workaround.

This solution, on the other hand, prevents D3D11 from culling out unused fragment input by adding each of them via regex and passing them in the output structure.

Tested to work with Parallels, with no major differences performance-wise.

[smoogipoo]

Seems okay, just a few nits.

[smoogipoo]

Must revert ppy/osu-resources#249

Can you explain why it "must" be reverted? As far as I understand this change should work regardless?

[frenzibyte]

Since that PR requires osu!-side changes, it's better to revert it and close the osu!-side PR rather than the other way around.

Now that I look at it though, I thought the changes required osu! to use a different vertex type, but it seems the only changes required are just using the new vertex shader, so it's not that big of a deal.

[peppy]

What's the status of this PR? Might be worth revisiting and closing if deemed unnecessary at this point, or bringing up-to-date.

[frenzibyte]

It's still valid for merge and would avoid all the vertex shaders that were created specifically to work around the limitation resolved by this PR (e.g. sh_Blur.vs and sh_LogoAnimation.vs)

[peppy]

👍

Needs some conflict resolution at very least then

[frenzibyte]

Have updated this now, but do note that I haven't tested it on DirectX because compiling and running on a VM is kind of a pain for me. Testing and making sure blurred framebuffers renders correctly on DirectX would be appreciated.