Examples: Win32+DX12: Tweaks.

Author: ocornut

backends/imgui_impl_dx12.cpp

@@ -6,6 +6,9 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
+// The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
+// IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
+
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
 // Learn about Dear ImGui:

backends/imgui_impl_dx12.h

@@ -6,6 +6,9 @@
 //  [X] Renderer: Large meshes support (64k+ vertices) with 16-bit indices.
 //  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
 
+// The aim of imgui_impl_dx12.h/.cpp is to be usable in your engine without any modification.
+// IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/
+
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
 // Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
 // Learn about Dear ImGui:

examples/example_win32_directx12/main.cpp

@@ -22,20 +22,20 @@
 #pragma comment(lib, "dxguid.lib")
 #endif
 
-#include "imgui_internal.h"
+// Config for example app
+static const int APP_NUM_FRAMES_IN_FLIGHT = 3;
+static const int APP_NUM_BACK_BUFFERS = 3;
 
 struct FrameContext
 {
-    ID3D12CommandAllocator* CommandAllocator;
-    UINT64                  FenceValue;
+    ID3D12CommandAllocator*     CommandAllocator;
+    UINT64                      FenceValue;
 };
 
 // Data
-static int const                    NUM_FRAMES_IN_FLIGHT = 3;
-static FrameContext                 g_frameContext[NUM_FRAMES_IN_FLIGHT] = {};
+static FrameContext                 g_frameContext[APP_NUM_FRAMES_IN_FLIGHT] = {};
 static UINT                         g_frameIndex = 0;
 
-static int const                    NUM_BACK_BUFFERS = 3;
 static ID3D12Device*                g_pd3dDevice = nullptr;
 static ID3D12DescriptorHeap*        g_pd3dRtvDescHeap = nullptr;
 static ID3D12DescriptorHeap*        g_pd3dSrvDescHeap = nullptr;
@@ -47,8 +47,8 @@ static UINT64                       g_fenceLastSignaledValue = 0;
 static IDXGISwapChain3*             g_pSwapChain = nullptr;
 static bool                         g_SwapChainOccluded = false;
 static HANDLE                       g_hSwapChainWaitableObject = nullptr;
-static ID3D12Resource*              g_mainRenderTargetResource[NUM_BACK_BUFFERS] = {};
-static D3D12_CPU_DESCRIPTOR_HANDLE  g_mainRenderTargetDescriptor[NUM_BACK_BUFFERS] = {};
+static ID3D12Resource*              g_mainRenderTargetResource[APP_NUM_BACK_BUFFERS] = {};
+static D3D12_CPU_DESCRIPTOR_HANDLE  g_mainRenderTargetDescriptor[APP_NUM_BACK_BUFFERS] = {};
 
 // Forward declarations of helper functions
 bool CreateDeviceD3D(HWND hWnd);
@@ -249,7 +249,7 @@ bool CreateDeviceD3D(HWND hWnd)
     DXGI_SWAP_CHAIN_DESC1 sd;
     {
         ZeroMemory(&sd, sizeof(sd));
-        sd.BufferCount = NUM_BACK_BUFFERS;
+        sd.BufferCount = APP_NUM_BACK_BUFFERS;
         sd.Width = 0;
         sd.Height = 0;
         sd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
@@ -292,15 +292,15 @@ bool CreateDeviceD3D(HWND hWnd)
     {
         D3D12_DESCRIPTOR_HEAP_DESC desc = {};
         desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
-        desc.NumDescriptors = NUM_BACK_BUFFERS;
+        desc.NumDescriptors = APP_NUM_BACK_BUFFERS;
         desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
         desc.NodeMask = 1;
         if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dRtvDescHeap)) != S_OK)
             return false;
 
         SIZE_T rtvDescriptorSize = g_pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
         D3D12_CPU_DESCRIPTOR_HANDLE rtvHandle = g_pd3dRtvDescHeap->GetCPUDescriptorHandleForHeapStart();
-        for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
+        for (UINT i = 0; i < APP_NUM_BACK_BUFFERS; i++)
         {
             g_mainRenderTargetDescriptor[i] = rtvHandle;
             rtvHandle.ptr += rtvDescriptorSize;
@@ -325,7 +325,7 @@ bool CreateDeviceD3D(HWND hWnd)
             return false;
     }
 
-    for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
+    for (UINT i = 0; i < APP_NUM_FRAMES_IN_FLIGHT; i++)
         if (g_pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&g_frameContext[i].CommandAllocator)) != S_OK)
             return false;
 
@@ -351,7 +351,7 @@ bool CreateDeviceD3D(HWND hWnd)
             return false;
         swapChain1->Release();
         dxgiFactory->Release();
-        g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);
+        g_pSwapChain->SetMaximumFrameLatency(APP_NUM_BACK_BUFFERS);
         g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
     }
 
@@ -364,7 +364,7 @@ void CleanupDeviceD3D()
     CleanupRenderTarget();
     if (g_pSwapChain) { g_pSwapChain->SetFullscreenState(false, nullptr); g_pSwapChain->Release(); g_pSwapChain = nullptr; }
     if (g_hSwapChainWaitableObject != nullptr) { CloseHandle(g_hSwapChainWaitableObject); }
-    for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
+    for (UINT i = 0; i < APP_NUM_FRAMES_IN_FLIGHT; i++)
         if (g_frameContext[i].CommandAllocator) { g_frameContext[i].CommandAllocator->Release(); g_frameContext[i].CommandAllocator = nullptr; }
     if (g_pd3dCommandQueue) { g_pd3dCommandQueue->Release(); g_pd3dCommandQueue = nullptr; }
     if (g_pd3dCommandList) { g_pd3dCommandList->Release(); g_pd3dCommandList = nullptr; }
@@ -386,7 +386,7 @@ void CleanupDeviceD3D()
 
 void CreateRenderTarget()
 {
-    for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
+    for (UINT i = 0; i < APP_NUM_BACK_BUFFERS; i++)
     {
         ID3D12Resource* pBackBuffer = nullptr;
         g_pSwapChain->GetBuffer(i, IID_PPV_ARGS(&pBackBuffer));
@@ -399,13 +399,13 @@ void CleanupRenderTarget()
 {
     WaitForLastSubmittedFrame();
 
-    for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
+    for (UINT i = 0; i < APP_NUM_BACK_BUFFERS; i++)
         if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = nullptr; }
 }
 
 void WaitForLastSubmittedFrame()
 {
-    FrameContext* frameCtx = &g_frameContext[g_frameIndex % NUM_FRAMES_IN_FLIGHT];
+    FrameContext* frameCtx = &g_frameContext[g_frameIndex % APP_NUM_FRAMES_IN_FLIGHT];
 
     UINT64 fenceValue = frameCtx->FenceValue;
     if (fenceValue == 0)
@@ -427,7 +427,7 @@ FrameContext* WaitForNextFrameResources()
     HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, nullptr };
     DWORD numWaitableObjects = 1;
 
-    FrameContext* frameCtx = &g_frameContext[nextFrameIndex % NUM_FRAMES_IN_FLIGHT];
+    FrameContext* frameCtx = &g_frameContext[nextFrameIndex % APP_NUM_FRAMES_IN_FLIGHT];
     UINT64 fenceValue = frameCtx->FenceValue;
     if (fenceValue != 0) // means no fence was signaled
     {