Resize Texture2D DirectX 11 c++

[AhmedX6]

Hello,

Is it possible to resize a texture2D obtained from AcquireNextFrame function ?
I would like to decrease the resolution of the image using DirectX11.

Thanks

[walbourn]

The easiest way to do the resize is to just create a new texture that is the size you want with the option to bind as both a shader resource view and as a render target. Then render to that new texture a full-screen quad (using SpriteBatch) of the original image. This leverages the GPU to do the resizing.

Alternatively, if you need a CPU solution the DirectXTex library supports a number of resizing options.

[AhmedX6]

Hello Walbourn,

Thank you for your help.
Can you please show me some code ? I need the pixel buffer resized after applying SpriteBatch resizing.
Here is my code :
if (gRealTexture == nullptr) { D3D11_TEXTURE2D_DESC description; texture2D->GetDesc(&description); description.BindFlags = 0; description.CPUAccessFlags = D3D11_CPU_ACCESS_READ | D3D11_CPU_ACCESS_WRITE; description.Usage = D3D11_USAGE_STAGING; description.MiscFlags = 0; hr = gDevice->CreateTexture2D(&description, NULL, &gRealTexture); if (FAILED(hr)) { if (gRealTexture) { gRealTexture->Release(); gRealTexture = nullptr; } return NULL; } }
this is the texture I have from AcquireNextFrame. I can map it and get pixel buffer data. (1920x1080x4)
Now before get the pixel buffer, I would like to resize the realTexture.
Here is the texture I created (1280x720)
if (gScaledTexture == nullptr) { D3D11_TEXTURE2D_DESC description; description.BindFlags = D3D11_BIND_RENDER_TARGET | D3D11_BIND_SHADER_RESOURCE; description.CPUAccessFlags = 0; description.Usage = D3D11_USAGE_DEFAULT; description.MiscFlags = 0; description.Width = 1280; description.Height = 720; hr = gDevice->CreateTexture2D(&description, NULL, &gScaledTexture); if (FAILED(hr)) { if (gRealTexture) { gRealTexture->Release(); gRealTexture = nullptr; } return NULL; } }
how to use SpriteBatch to copy the RealTexture into the ScaledTexture ?
Thank you I'm totally stuck...

[walbourn]

SpriteBatch can only render to textures that are something other than USAGE_STAGING. If you need to read back the texture from the GPU to the CPU, then you'd use CopyResource to get it from a USAGE_DEFAULT to a USAGE_STAGING texture. Note that CopyResource will not do resizing, so you need to make sure you've already done the resize on the GPU before copying it.

[AhmedX6]

The texture with USAGE_STAGING is the texture I get from AcquireNextFrame. I can copy resource on a texture with USAGE_DEFAULT with the same resolution. But how to reduce resolution after that ?
Can you please show me a sample code with SpriteBatch and D3D11Texture2D ?
Thank you very much for your help.

[walbourn]

I don't really have the time on-hand to code up a full solution, but if you already have everything in CPU memory (which is what's happening with USAGE_STAGING) rather than on the GPU, then you should probably just look at using DirectXTex to do the resize on the CPU. The SpriteBatch render-to-texture solution only makes sense if your original is on the GPU and you want to create a new smaller texture on the GPU.

[AhmedX6]

Oh okk so I should check with DirectXTex.
Please can you tell me which function in particular in DirectXTex should I use for my case ?
Thanks

[walbourn]

I don't understand your usage case in detail here, but you can find docs on the DirectXTex Resize function here.

[kmaki565]

For those who have the same question...
I followed the first advice of @walbourn and created a simple app to do this: https://github.com/kmaki565/ResizeGfx
Also integrated it to a screen recorder solution: sskodje/ScreenRecorderLib#136