The page content looks a bit blurry

[LItterBoy-GB]

Version/Branch of Dear ImGui:

Version 1.91.3

Back-ends:

imgui_impl_win32.cpp + imgui_impl_dx12.cpp

Compiler, OS:

Windows11 + VS2022

Full config/build information:

https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx12/main.cpp

https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples#example-for-directx12-users

Details:

I know this shouldn't be ImGui's problem, I may need to adjust the dx12 related parameters, but I don't know how to handle it.

I use the example (example-for-directx12-users). I found that the loaded image is a bit blurry And with the same resources, we also compared it with WPF.

Screenshots/Video:

Minimal, Complete and Verifiable Example code:

https://github.com/ocornut/imgui/blob/master/examples/example_win32_directx12/main.cpp

https://github.com/ocornut/imgui/wiki/Image-Loading-and-Displaying-Examples#example-for-directx12-users

[ocornut]

You need to make sure the application process is DPI aware, otherwise Windows reduce sizes and then perform scaling.

eg call ImGui_ImplWin32_EnableDpiAwareness() is one possible way to make the process dpi aware.

[LItterBoy-GB]

You need to make sure the application process is DPI aware, otherwise Windows reduce sizes and then perform scaling.

eg call ImGui_ImplWin32_EnableDpiAwareness() is one possible way to make the process dpi aware.

My screen DPI is 96, pixels are 1960 * 1080p, and the size is 24 inches The window system has not performed display scaling

[ocornut]

Then I don't know what your problem is.

[ocornut]

I am not sure, given the grey fringe, it could be that the image use transparency and use premultiplied alpha? Our blending settings don't (btw it was not a good idea on my end). You can use a ImDrawList callback to alter blending settings when drawing your images. May start by modifying the D3D12_BLEND_DESC in imgui_impl_dx12.cpp to check if the image looks correct with that change.

See https://github.com/microsoft/DirectXTK12/blob/main/Src/CommonStates.cpp

We are using:

D3D12_BLEND_DESC& desc = psoDesc.BlendState;
desc.AlphaToCoverageEnable = false;
desc.RenderTarget[0].BlendEnable = true;
desc.RenderTarget[0].SrcBlend = D3D12_BLEND_SRC_ALPHA;
desc.RenderTarget[0].DestBlend = D3D12_BLEND_INV_SRC_ALPHA;
desc.RenderTarget[0].BlendOp = D3D12_BLEND_OP_ADD;
desc.RenderTarget[0].SrcBlendAlpha = D3D12_BLEND_ONE;
desc.RenderTarget[0].DestBlendAlpha = D3D12_BLEND_INV_SRC_ALPHA;
desc.RenderTarget[0].BlendOpAlpha = D3D12_BLEND_OP_ADD;
desc.RenderTarget[0].RenderTargetWriteMask = D3D12_COLOR_WRITE_ENABLE_ALL;

Which corresponds more or less to CommonStates::NonPremultiplied (not exactly).

Try to change SrcBlend:

desc.RenderTarget[0].SrcBlend = D3D12_BLEND_ONE;

[LItterBoy-GB]

I am not sure, given the grey fringe, it could be that the image use transparency and use premultiplied alpha? Our blending settings don't (btw it was not a good idea on my end). You can use a ImDrawList callback to alter blending settings when drawing your images. May start by modifying the D3D12_BLEND_DESC in imgui_impl_dx12.cpp to check if the image looks correct with that change.

Thank you. the image use transparency and use premultiplied alpha.

After adjustment, the transparent edge feels even more uncomfortable.

[ocornut]

Unfortunately as you pointed this not much of this has to do with dear imgui itself.

When you call Image() it emits a ImDrawCmd (you can browse/look at it in details in Metrics->DrawList to see the 4 vertices) which is equivalent to what you would in DX12 by emitting emitted 2 textured triangles to form a rectangle. Maybe there's a pixel alignment issue, I don't know. But you would need to try emitting that yourself or emit vertices manually and see if you can get it to match. Otherwise it can come from a million factors.

Maybe try to create a perfect pixel-grid image, and compare exact output with WPF and our DX12 example to understand what's going on.

The window system has not performed display scaling

I assume you did call that function I mentioned tho, to rule out that possibility?

I am sorry I don't have much resources to help you debug this so I am going to close it, but feel free to post details of your investigation.