Please add support of Texture.CopyTexture()

[JohnMasen]

Description (optional)

I found the library is using texture copy inside AllocateReadOnlyTexture2D<T,TPixel>(), however the texture copy method is not exposed to public.
The idea is able to create a texture processing pipleline like this:
Upload ->CopyTo Texture -> Process Texture ->Readback result

Rationale

I'm trying to use ComputeSharp to build a fast image resize/resample pipeline for AI Model(ONNX) inference, the stream from video source is RGBA32 format, I wish I could use UploadTexutre2D to upload the stream then copy it to ReadOnlyTexture2D .

Proposed API

Add CopyTexture<TSource,TTarget>(Texture texture) to UploadTexture.

Drawbacks

TBD

Alternatives

Other thoughts

It is also suggested add a customer type mapper to allow map user data structure to DXPixelFormat just like DXGIFormatHelper. User can create UploadTexture/ReadOnlyTexture with the custom mapper to

1. Map ImageSharp pixel formats directly to DirectX PixelFormats without MemoryMarshal.Cast()
2. use DXGI_FORMAT_NV12 directly from DXVA GPU decoded video frame

example:
device.AllocateUploadTexture2D(ReadonlySpan buffer, int w, int h, DXGITypeMapper mapper );

Thanks

[Sergio0694]

Duplicate of #215 🙂