Backends: DirectX12: Texture upload use the command queue provided in ImGui_ImplDX12_InitInfo instead of creating its own.

+ minor tweaks to faciliate branch merging.

backends/imgui_impl_dx12.cpp

@@ -19,6 +19,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2025-01-15: DirectX12: Texture upload use the command queue provided in ImGui_ImplDX12_InitInfo instead of creating its own.
 //  2024-12-09: DirectX12: Let user specifies the DepthStencilView format by setting ImGui_ImplDX12_InitInfo::DSVFormat.
 //  2024-11-15: DirectX12: *BREAKING CHANGE* Changed ImGui_ImplDX12_Init() signature to take a ImGui_ImplDX12_InitInfo struct. Legacy ImGui_ImplDX12_Init() signature is still supported (will obsolete).
 //  2024-11-15: DirectX12: *BREAKING CHANGE* User is now required to pass function pointers to allocate/free SRV Descriptors. We provide convenience legacy fields to pass a single descriptor, matching the old API, but upcoming features will want multiple.
@@ -64,6 +65,8 @@ struct ImGui_ImplDX12_Texture
     ID3D12Resource*             pTextureResource;
     D3D12_CPU_DESCRIPTOR_HANDLE hFontSrvCpuDescHandle;
     D3D12_GPU_DESCRIPTOR_HANDLE hFontSrvGpuDescHandle;
+
+    ImGui_ImplDX12_Texture()    { memset((void*)this, 0, sizeof(*this)); }
 };
 
 struct ImGui_ImplDX12_Data
@@ -180,8 +183,7 @@ void ImGui_ImplDX12_RenderDrawData(ImDrawData* draw_data, ID3D12GraphicsCommandL
     if (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f)
         return;
 
-    // FIXME: I'm assuming that this only gets called once per frame!
+    // FIXME: We are assuming that this only gets called once per frame!
-    // If not, we can't just re-allocate the IB or VB, we'll have to do a proper allocator.
     ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
     bd->frameIndex = bd->frameIndex + 1;
     ImGui_ImplDX12_RenderBuffers* fr = &bd->pFrameResources[bd->frameIndex % bd->numFramesInFlight];
@@ -352,11 +354,11 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         bd->pd3dDevice->CreateCommittedResource(&props, D3D12_HEAP_FLAG_NONE, &desc,
             D3D12_RESOURCE_STATE_COPY_DEST, nullptr, IID_PPV_ARGS(&pTexture));
 
-        UINT uploadPitch = (width * 4 + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
+        UINT upload_pitch = (width * 4 + D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u) & ~(D3D12_TEXTURE_DATA_PITCH_ALIGNMENT - 1u);
-        UINT uploadSize = height * uploadPitch;
+        UINT upload_size = height * upload_pitch;
         desc.Dimension = D3D12_RESOURCE_DIMENSION_BUFFER;
         desc.Alignment = 0;
-        desc.Width = uploadSize;
+        desc.Width = upload_size;
         desc.Height = 1;
         desc.DepthOrArraySize = 1;
         desc.MipLevels = 1;
@@ -376,26 +378,28 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         IM_ASSERT(SUCCEEDED(hr));
 
         void* mapped = nullptr;
-        D3D12_RANGE range = { 0, uploadSize };
+        D3D12_RANGE range = { 0, upload_size };
         hr = uploadBuffer->Map(0, &range, &mapped);
         IM_ASSERT(SUCCEEDED(hr));
         for (int y = 0; y < height; y++)
-            memcpy((void*) ((uintptr_t) mapped + y * uploadPitch), pixels + y * width * 4, width * 4);
+            memcpy((void*) ((uintptr_t) mapped + y * upload_pitch), pixels + y * width * 4, width * 4);
         uploadBuffer->Unmap(0, &range);
 
         D3D12_TEXTURE_COPY_LOCATION srcLocation = {};
+        D3D12_TEXTURE_COPY_LOCATION dstLocation = {};
+        {
             srcLocation.pResource = uploadBuffer;
             srcLocation.Type = D3D12_TEXTURE_COPY_TYPE_PLACED_FOOTPRINT;
             srcLocation.PlacedFootprint.Footprint.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
             srcLocation.PlacedFootprint.Footprint.Width = width;
             srcLocation.PlacedFootprint.Footprint.Height = height;
             srcLocation.PlacedFootprint.Footprint.Depth = 1;
-        srcLocation.PlacedFootprint.Footprint.RowPitch = uploadPitch;
+            srcLocation.PlacedFootprint.Footprint.RowPitch = upload_pitch;
 
-        D3D12_TEXTURE_COPY_LOCATION dstLocation = {};
             dstLocation.pResource = pTexture;
             dstLocation.Type = D3D12_TEXTURE_COPY_TYPE_SUBRESOURCE_INDEX;
             dstLocation.SubresourceIndex = 0;
+        }
 
         D3D12_RESOURCE_BARRIER barrier = {};
         barrier.Type = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
@@ -412,15 +416,6 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         HANDLE event = ::CreateEvent(0, 0, 0, 0);
         IM_ASSERT(event != nullptr);
 
-        D3D12_COMMAND_QUEUE_DESC queueDesc = {};
-        queueDesc.Type     = D3D12_COMMAND_LIST_TYPE_DIRECT;
-        queueDesc.Flags    = D3D12_COMMAND_QUEUE_FLAG_NONE;
-        queueDesc.NodeMask = 1;
-
-        ID3D12CommandQueue* cmdQueue = nullptr;
-        hr = bd->pd3dDevice->CreateCommandQueue(&queueDesc, IID_PPV_ARGS(&cmdQueue));
-        IM_ASSERT(SUCCEEDED(hr));
-
         ID3D12CommandAllocator* cmdAlloc = nullptr;
         hr = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&cmdAlloc));
         IM_ASSERT(SUCCEEDED(hr));
@@ -435,6 +430,7 @@ static void ImGui_ImplDX12_CreateFontsTexture()
         hr = cmdList->Close();
         IM_ASSERT(SUCCEEDED(hr));
 
+        ID3D12CommandQueue* cmdQueue = bd->InitInfo.CommandQueue;
         cmdQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmdList);
         hr = cmdQueue->Signal(fence, 1);
         IM_ASSERT(SUCCEEDED(hr));
@@ -444,7 +440,6 @@ static void ImGui_ImplDX12_CreateFontsTexture()
 
         cmdList->Release();
         cmdAlloc->Release();
-        cmdQueue->Release();
         ::CloseHandle(event);
         fence->Release();
         uploadBuffer->Release();
@@ -707,11 +702,11 @@ void    ImGui_ImplDX12_InvalidateDeviceObjects()
     if (!bd || !bd->pd3dDevice)
         return;
 
-    ImGuiIO& io = ImGui::GetIO();
     SafeRelease(bd->pRootSignature);
     SafeRelease(bd->pPipelineState);
 
     // Free SRV descriptor used by texture
+    ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplDX12_Texture* font_tex = &bd->FontTexture;
     bd->InitInfo.SrvDescriptorFreeFn(&bd->InitInfo, font_tex->hFontSrvCpuDescHandle, font_tex->hFontSrvGpuDescHandle);
     SafeRelease(font_tex->pTextureResource);

docs/CHANGELOG.txt

@@ -43,6 +43,9 @@ Breaking changes:
 
 Other changes:
 
+- Backends: DirectX12: Texture upload use the command queue provided in
+  ImGui_ImplDX12_InitInfo instead of creating its own.
+
 
 -----------------------------------------------------------------------
  VERSION 1.91.7 (Released 2025-01-14)

imgui.cpp

@@ -5086,6 +5086,7 @@ void ImGui::UpdateHoveredWindowAndCaptureFlags()
 }
 
 // Called once a frame. Followed by SetCurrentFont() which sets up the remaining data.
+// FIXME-VIEWPORT: the concept of a single ClipRectFullscreen is not ideal!
 static void SetupDrawListSharedData()
 {
     ImGuiContext& g = *GImGui;