Backends: DX12: Rework synchronization logic. (docking) (#8961)

This commit is contained in:
Rémy Tassoux
2025-09-29 16:23:50 +02:00
committed by ocornut
parent 1aa91ac426
commit 778aadca65
2 changed files with 51 additions and 30 deletions

View File

@@ -135,6 +135,7 @@ struct ImGui_ImplDX12_RenderBuffers
// Buffers used for secondary viewports created by the multi-viewports systems
struct ImGui_ImplDX12_FrameContext
{
UINT64 FenceValue;
ID3D12CommandAllocator* CommandAllocator;
ID3D12Resource* RenderTarget;
D3D12_CPU_DESCRIPTOR_HANDLE RenderTargetCpuDescriptors;
@@ -150,8 +151,9 @@ struct ImGui_ImplDX12_ViewportData
ID3D12GraphicsCommandList* CommandList;
ID3D12DescriptorHeap* RtvDescHeap;
IDXGISwapChain3* SwapChain;
HANDLE SwapChainWaitableObject;
ID3D12Fence* Fence;
UINT64 FenceSignaledValue;
UINT64 FenceLastSignaledValue;
HANDLE FenceEvent;
UINT NumFramesInFlight;
ImGui_ImplDX12_FrameContext* FrameCtx;
@@ -166,16 +168,18 @@ struct ImGui_ImplDX12_ViewportData
CommandList = nullptr;
RtvDescHeap = nullptr;
SwapChain = nullptr;
SwapChainWaitableObject = nullptr;
Fence = nullptr;
FenceSignaledValue = 0;
FenceLastSignaledValue = 0;
FenceEvent = nullptr;
NumFramesInFlight = num_frames_in_flight;
FrameCtx = new ImGui_ImplDX12_FrameContext[NumFramesInFlight];
FrameIndex = UINT_MAX;
FrameIndex = 0;
FrameRenderBuffers = new ImGui_ImplDX12_RenderBuffers[NumFramesInFlight];
for (UINT i = 0; i < NumFramesInFlight; ++i)
{
FrameCtx[i].FenceValue = 0;
FrameCtx[i].CommandAllocator = nullptr;
FrameCtx[i].RenderTarget = nullptr;
@@ -191,6 +195,7 @@ struct ImGui_ImplDX12_ViewportData
IM_ASSERT(CommandQueue == nullptr && CommandList == nullptr);
IM_ASSERT(RtvDescHeap == nullptr);
IM_ASSERT(SwapChain == nullptr);
IM_ASSERT(SwapChainWaitableObject == nullptr);
IM_ASSERT(Fence == nullptr);
IM_ASSERT(FenceEvent == nullptr);
@@ -1043,18 +1048,12 @@ static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
HWND hwnd = viewport->PlatformHandleRaw ? (HWND)viewport->PlatformHandleRaw : (HWND)viewport->PlatformHandle;
IM_ASSERT(hwnd != 0);
vd->FrameIndex = UINT_MAX;
// Create command queue.
D3D12_COMMAND_QUEUE_DESC queue_desc = {};
queue_desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
queue_desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
HRESULT res = S_OK;
res = bd->pd3dDevice->CreateCommandQueue(&queue_desc, IID_PPV_ARGS(&vd->CommandQueue));
IM_ASSERT(res == S_OK);
// Use shared command queue from init info
vd->FrameIndex = 0;
vd->CommandQueue = bd->pCommandQueue;
// Create command allocator.
HRESULT res = S_OK;
for (UINT i = 0; i < bd->numFramesInFlight; ++i)
{
res = bd->pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&vd->FrameCtx[i].CommandAllocator));
@@ -1088,6 +1087,7 @@ static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
sd1.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
sd1.Scaling = DXGI_SCALING_NONE;
sd1.Stereo = FALSE;
sd1.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
IDXGIFactory4* dxgi_factory = nullptr;
res = ::CreateDXGIFactory1(IID_PPV_ARGS(&dxgi_factory));
@@ -1106,7 +1106,7 @@ static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
swap_chain->QueryInterface(IID_PPV_ARGS(&vd->SwapChain));
swap_chain->Release();
// Create the render targets
// Create the render targets and waitable object
if (vd->SwapChain)
{
D3D12_DESCRIPTOR_HEAP_DESC desc = {};
@@ -1134,6 +1134,10 @@ static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
bd->pd3dDevice->CreateRenderTargetView(back_buffer, nullptr, vd->FrameCtx[i].RenderTargetCpuDescriptors);
vd->FrameCtx[i].RenderTarget = back_buffer;
}
hr = vd->SwapChain->SetMaximumFrameLatency(bd->numFramesInFlight);
IM_ASSERT(hr == S_OK);
vd->SwapChainWaitableObject = vd->SwapChain->GetFrameLatencyWaitableObject();
}
for (UINT i = 0; i < bd->numFramesInFlight; i++)
@@ -1142,16 +1146,29 @@ static void ImGui_ImplDX12_CreateWindow(ImGuiViewport* viewport)
static void ImGui_WaitForPendingOperations(ImGui_ImplDX12_ViewportData* vd)
{
HRESULT hr = S_FALSE;
if (vd && vd->CommandQueue && vd->Fence && vd->FenceEvent)
{
hr = vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
HRESULT hr = vd->CommandQueue->Signal(vd->Fence, ++vd->FenceLastSignaledValue);
IM_ASSERT(hr == S_OK);
::WaitForSingleObject(vd->FenceEvent, 0); // Reset any forgotten waits
hr = vd->Fence->SetEventOnCompletion(vd->FenceSignaledValue, vd->FenceEvent);
hr = vd->Fence->SetEventOnCompletion(vd->FenceLastSignaledValue, vd->FenceEvent);
IM_ASSERT(hr == S_OK);
::WaitForSingleObject(vd->FenceEvent, INFINITE);
}
static ImGui_ImplDX12_FrameContext* ImGui_WaitForNextFrameContext(ImGui_ImplDX12_ViewportData* vd)
{
ImGui_ImplDX12_FrameContext* frame_context = &vd->FrameCtx[vd->FrameIndex % vd->NumFramesInFlight];
if (vd->Fence->GetCompletedValue() < frame_context->FenceValue)
{
HRESULT hr = vd->Fence->SetEventOnCompletion(frame_context->FenceValue, vd->FenceEvent);
IM_ASSERT(hr == S_OK);
HANDLE waitableObjects[] = { vd->SwapChainWaitableObject, vd->FenceEvent };
::WaitForMultipleObjects(2, waitableObjects, TRUE, INFINITE);
}
else
{
::WaitForSingleObject(vd->SwapChainWaitableObject, INFINITE);
}
return frame_context;
}
static void ImGui_ImplDX12_DestroyWindow(ImGuiViewport* viewport)
@@ -1162,7 +1179,9 @@ static void ImGui_ImplDX12_DestroyWindow(ImGuiViewport* viewport)
{
ImGui_WaitForPendingOperations(vd);
SafeRelease(vd->CommandQueue);
vd->CommandQueue = nullptr;
::CloseHandle(vd->SwapChainWaitableObject);
vd->SwapChainWaitableObject = nullptr;
SafeRelease(vd->CommandList);
SafeRelease(vd->SwapChain);
SafeRelease(vd->RtvDescHeap);
@@ -1194,7 +1213,7 @@ static void ImGui_ImplDX12_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
if (vd->SwapChain)
{
ID3D12Resource* back_buffer = nullptr;
vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, 0);
vd->SwapChain->ResizeBuffers(0, (UINT)size.x, (UINT)size.y, DXGI_FORMAT_UNKNOWN, DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT);
for (UINT i = 0; i < bd->numFramesInFlight; i++)
{
vd->SwapChain->GetBuffer(i, IID_PPV_ARGS(&back_buffer));
@@ -1209,7 +1228,7 @@ static void ImGui_ImplDX12_RenderWindow(ImGuiViewport* viewport, void*)
ImGui_ImplDX12_Data* bd = ImGui_ImplDX12_GetBackendData();
ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
ImGui_ImplDX12_FrameContext* frame_context = &vd->FrameCtx[vd->FrameIndex % bd->numFramesInFlight];
ImGui_ImplDX12_FrameContext* frame_context = ImGui_WaitForNextFrameContext(vd);
UINT back_buffer_idx = vd->SwapChain->GetCurrentBackBufferIndex();
const ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
@@ -1239,9 +1258,11 @@ static void ImGui_ImplDX12_RenderWindow(ImGuiViewport* viewport, void*)
cmd_list->ResourceBarrier(1, &barrier);
cmd_list->Close();
vd->CommandQueue->Wait(vd->Fence, vd->FenceSignaledValue);
vd->CommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&cmd_list);
vd->CommandQueue->Signal(vd->Fence, ++vd->FenceSignaledValue);
HRESULT hr = vd->CommandQueue->Signal(vd->Fence, ++vd->FenceLastSignaledValue);
IM_ASSERT(hr == S_OK);
frame_context->FenceValue = vd->FenceLastSignaledValue;
}
static void ImGui_ImplDX12_SwapBuffers(ImGuiViewport* viewport, void*)
@@ -1249,8 +1270,7 @@ static void ImGui_ImplDX12_SwapBuffers(ImGuiViewport* viewport, void*)
ImGui_ImplDX12_ViewportData* vd = (ImGui_ImplDX12_ViewportData*)viewport->RendererUserData;
vd->SwapChain->Present(0, 0);
while (vd->Fence->GetCompletedValue() < vd->FenceSignaledValue)
::SwitchToThread();
vd->FrameIndex++;
}
void ImGui_ImplDX12_InitMultiViewportSupport()

View File

@@ -295,8 +295,6 @@ int main(int, char**)
g_pd3dCommandList->Close();
g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
frameCtx->FenceValue = g_fenceLastSignaledValue;
// Update and Render additional Platform Windows
if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
@@ -305,6 +303,9 @@ int main(int, char**)
ImGui::RenderPlatformWindowsDefault();
}
g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
frameCtx->FenceValue = g_fenceLastSignaledValue;
// Present
HRESULT hr = g_pSwapChain->Present(1, 0); // Present with vsync
//HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync