GPU D3D12 - Update to use typeless formats for depth buffer

[gyxos-logan]

Description

For a depth buffer in D3D12 that is also going to be used in a texture sampler, the creation (on an Intel HD 5500 igpu) fails. e.g. SDL_GPUTextureCreateInfo type = TEXTURE_2D, format = D32_FLOAT, usage = DEPTH_STENCIL_TARGET | SAMPLER

The error messages are:

• D32_FLOAT
  D3D12 ERROR: ID3D12Device::CreateShaderResourceView: The Format (0x29, R32_FLOAT) is invalid when creating a View; the
  Resource was already created with a fully qualified Format, which is not castable (0x28, D32_FLOAT).

• D24_UNORM
  D3D12 ERROR: ID3D12Device::CreateShaderResourceView: For the resource format D24_UNORM_S8_UINT, when making a D3D view, the format name for the view can't be R24_UNORM_X8_TYPELESS.

Fix

I found this is because the texture format needs to be created as _TYPELESS, then the views (depth stencil view, shader resource view) should then be created as their respective types - e.g. texture = R32_TYPELESS, dsv = D32_FLOAT, srv = R32_FLOAT

Tested and working on:
NVidia RTX 3050 (D3D12 feature set 12_2)
Intel HD 5500 (D3D12 feature set 11_1)

Further changes/improvements?

Happy to any changes as needed.

[thatcosmonaut]

This seems generally fine but I think we should only create the sampler views if the sampler bit is set.

[gyxos-logan]

I've made a change to make it more clear when the SRV view is created and only use the typeless format when that is being created. Hopefully this is what you were meaning.