D3D12 back-end debug warning on empty scissor rectangle

[BeastLe9enD]

Hello,
its seems that there is a bug in the D3D12 version that let imgui crash if you draw many objects.
If u want to test it yourself, just show the demo window and open all tree nodes / collapsing headers

it crashs at
ctx->DrawIndexedInstanced(pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
in RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandList* ctx)

[ocornut]

What happened then?

[BeastLe9enD]

My fault was to tell the info queue to crash when warnings occured, thats why I closed the issue. Although, there is something against the spec, but it does not seem to cause graphical issues :)

D3D12 WARNING: ID3D12CommandList::DrawIndexedInstanced: Viewport: 0 is non-empty while the corresponding scissor rectangle is empty. Nothing will be written to the render target when this viewport is selected. In D3D12, scissor testing is always enabled. [ EXECUTION WARNING #695: DRAW_EMPTY_SCISSOR_RECTANGLE]
D3D12: BREAK enabled for the previous message, which was: [ WARNING EXECUTION #695: DRAW_EMPTY_SCISSOR_RECTANGLE ]

[ocornut]

Well, if somehow the library outputs data that makes the current DX12 back-end emit warnings we should fix either the back-end either the library. However I've been unable to reproduce that warning.

I even tried to add

IM_ASSERT(r.right > r.left);
IM_ASSERT(r.bottom > r.top);

In the render loop in ImGui_ImplDX12_RenderDrawData() and it never triggered.

Could you clarify:

• Which version are you using.
• The exact repro (e.g. can you get to repro in examples/example_win32_dx12/ ?
• How to enable the debug layer to break.

[BeastLe9enD]

Im using the newest docking branch,
its an own project with SDL2/D3D12 but im doing everything like in the example

To enable the debug layer:
First create a dxgi factory with debug:
IDXGIFactory7* pFactory; CreateDXGIFactory2(DXGI_CREATE_FACTORY_DEBUG, IID_PPV_ARGS(&pFactory));

Then create the debug interface:
ID3D12Debug* pDebugInterface; D3D12GetDebugInterface(IID_PPV_ARGS(&pDebugInterface)); pDebugInterface->EnableDebugLayer();

After that, query the info queue from the created d3d12 device:
ID3D12InfoQueue* pInfoQueue; m_pDevice->QueryInterface(IID_PPV_ARGS(&pInfoQueue)); pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_ERROR, true); pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_CORRUPTION, true); pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_WARNING, true);

There also seems to be a little bug with the multi-viewports, because the DXGI format of the pipeline state does not match with the format of the created multi-viewport window.

I fixed it with replacing the sd1.Format = DXGI_FORMAT_R8G8B8A8_UNORM; with sd1.Format = g_RTVFormat; so that the swapchain formats match!
(in imgui_impl_dx12.cpp) in line 789 (ImGui_ImplDX12_CreateWindow method)

[Hipster00]

Ok

[ocornut]

Thank you @BeastLe9enD! This has been fixed by #3472 and I've also added the SetBreakOnSeverity call in the demo code.

[ocornut]

There also seems to be a little bug with the multi-viewports, because the DXGI format of the pipeline state does not match with the format of the created multi-viewport window. I fixed it with replacing the sd1.Format = DXGI_FORMAT_R8G8B8A8_UNORM; with sd1.Format = g_RTVFormat; so that the swapchain formats match!
(in imgui_impl_dx12.cpp) in line 789 (ImGui_ImplDX12_CreateWindow method)

Also pushed this in docking branch with
e230ec5