Examples: DirectX9: Added support for multi-viewport (#2394)

examples/example_win32_directx9/main.cpp

@@ -49,6 +49,10 @@ void ResetDevice()
     ImGui_ImplDX9_CreateDeviceObjects();
 }
 
+#ifndef WM_DPICHANGED
+#define WM_DPICHANGED 0x02E0 // From Windows SDK 8.1+ headers
+#endif
+
 extern LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
 {
@@ -72,12 +76,23 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
     case WM_DESTROY:
         PostQuitMessage(0);
         return 0;
+    case WM_DPICHANGED:
+        if (ImGui::GetIO().ConfigFlags & ImGuiConfigFlags_DpiEnableScaleViewports)
+        {
+            //const int dpi = HIWORD(wParam);
+            //printf("WM_DPICHANGED to %d (%.0f%%)\n", dpi, (float)dpi / 96.0f * 100.0f);
+            const RECT* suggested_rect = (RECT*)lParam;
+            ::SetWindowPos(hWnd, NULL, suggested_rect->left, suggested_rect->top, suggested_rect->right - suggested_rect->left, suggested_rect->bottom - suggested_rect->top, SWP_NOZORDER | SWP_NOACTIVATE);
+        }
+        break;
     }
     return DefWindowProc(hWnd, msg, wParam, lParam);
 }
 
 int main(int, char**)
 {
+    ImGui_ImplWin32_EnableDpiAwareness();
+
     // Create application window
     WNDCLASSEX wc = { sizeof(WNDCLASSEX), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(NULL), NULL, NULL, NULL, NULL, _T("ImGui Example"), NULL };
     RegisterClassEx(&wc);
@@ -109,6 +124,14 @@ int main(int, char**)
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsClassic();
 
+    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
+    ImGuiStyle& style = ImGui::GetStyle();
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+    {
+        style.WindowRounding = 0.0f;
+        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+    }
+
     // Setup Platform/Renderer bindings
     ImGui_ImplWin32_Init(hwnd);
     ImGui_ImplDX9_Init(g_pd3dDevice);
@@ -205,6 +228,14 @@ int main(int, char**)
             ImGui_ImplDX9_RenderDrawData(ImGui::GetDrawData());
             g_pd3dDevice->EndScene();
         }
+
+        // Update and Render additional Platform Windows
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+        }
+
         HRESULT result = g_pd3dDevice->Present(NULL, NULL, NULL, NULL);
 
         // Handle loss of D3D9 device

examples/imgui_impl_dx9.cpp

@@ -3,6 +3,7 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
+//  [X] Renderer: Multi-viewport support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.
@@ -10,6 +11,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2019-01-16: Misc: Disabled fog before drawing UI's. Fixes issue #2288.
 //  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
 //  2018-06-08: Misc: Extracted imgui_impl_dx9.cpp/.h away from the old combined DX9+Win32 example.
@@ -41,6 +43,10 @@ struct CUSTOMVERTEX
 };
 #define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZ|D3DFVF_DIFFUSE|D3DFVF_TEX1)
 
+// Forward Declarations
+static void ImGui_ImplDX9_InitPlatformInterface();
+static void ImGui_ImplDX9_ShutdownPlatformInterface();
+
 // Render function.
 // (this used to be set in io.RenderDrawListsFn and called by ImGui::Render(), but you can now call this directly from your main loop)
 void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
@@ -203,16 +209,22 @@ void ImGui_ImplDX9_RenderDrawData(ImDrawData* draw_data)
 bool ImGui_ImplDX9_Init(IDirect3DDevice9* device)
 {
     ImGuiIO& io = ImGui::GetIO();
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;    // We can create multi-viewports on the Renderer side (optional)
     io.BackendRendererName = "imgui_impl_dx9";
 
     g_pd3dDevice = device;
+
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplDX9_InitPlatformInterface();
+
     return true;
 }
 
 void ImGui_ImplDX9_Shutdown()
 {
+    ImGui_ImplDX9_ShutdownPlatformInterface();
     ImGui_ImplDX9_InvalidateDeviceObjects();
-    g_pd3dDevice = NULL;
+    if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = NULL; }
 }
 
 static bool ImGui_ImplDX9_CreateFontsTexture()
@@ -278,3 +290,112 @@ void ImGui_ImplDX9_NewFrame()
     if (!g_FontTexture)
         ImGui_ImplDX9_CreateDeviceObjects();
 }
+
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the back-end to create and handle multiple viewports simultaneously.
+// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
+//--------------------------------------------------------------------------------------------------------
+
+struct ImGuiViewportDataDx9
+{
+    IDirect3DSwapChain9*    SwapChain;
+    D3DPRESENT_PARAMETERS   d3dpp;
+
+    ImGuiViewportDataDx9()  { SwapChain = NULL; ZeroMemory(&d3dpp, sizeof(D3DPRESENT_PARAMETERS)); }
+    ~ImGuiViewportDataDx9() { IM_ASSERT(SwapChain == NULL); }
+};
+
+static void ImGui_ImplDX9_CreateWindow(ImGuiViewport* viewport)
+{
+    ImGuiViewportDataDx9* data = IM_NEW(ImGuiViewportDataDx9)();
+    viewport->RendererUserData = data;
+
+    HWND hWnd = (HWND)viewport->PlatformHandle;
+    IM_ASSERT(hWnd != 0);
+
+    ZeroMemory(&data->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+    data->d3dpp.Windowed = TRUE;
+    data->d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
+    data->d3dpp.BackBufferFormat = D3DFMT_UNKNOWN;
+    data->d3dpp.hDeviceWindow = hWnd;
+    data->d3dpp.EnableAutoDepthStencil = TRUE;
+    data->d3dpp.AutoDepthStencilFormat = D3DFMT_D16;
+    data->d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;   // Present without vsync
+    
+    g_pd3dDevice->CreateAdditionalSwapChain(&data->d3dpp, &data->SwapChain);
+    IM_ASSERT(data->SwapChain != NULL);
+}
+
+static void ImGui_ImplDX9_DestroyWindow(ImGuiViewport* viewport)
+{
+    // The main viewport (owned by the application) will always have RendererUserData == NULL since we didn't create the data for it.
+    if (ImGuiViewportDataDx9* data = (ImGuiViewportDataDx9*)viewport->RendererUserData)
+    {
+        if (data->SwapChain)
+            data->SwapChain->Release();
+        data->SwapChain = NULL;
+        ZeroMemory(&data->d3dpp, sizeof(D3DPRESENT_PARAMETERS));
+        IM_DELETE(data);
+    }
+    viewport->RendererUserData = NULL;
+}
+
+static void ImGui_ImplDX9_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
+{
+    ImGuiViewportDataDx9* data = (ImGuiViewportDataDx9*)viewport->RendererUserData;
+    if (data->SwapChain)
+    {
+        data->SwapChain->Release();
+        data->SwapChain = NULL;
+        data->d3dpp.BackBufferWidth = (UINT)size.x;
+        data->d3dpp.BackBufferHeight = (UINT)size.y;
+        g_pd3dDevice->CreateAdditionalSwapChain(&data->d3dpp, &data->SwapChain);
+    }
+}
+
+static void ImGui_ImplDX9_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    ImGuiViewportDataDx9* data = (ImGuiViewportDataDx9*)viewport->RendererUserData;
+    ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+
+    LPDIRECT3DSURFACE9 render_target = NULL;
+    LPDIRECT3DSURFACE9 last_render_target = NULL;
+    data->SwapChain->GetBackBuffer(0, D3DBACKBUFFER_TYPE_MONO, &render_target);
+    g_pd3dDevice->GetRenderTarget(0, &last_render_target);
+    g_pd3dDevice->SetRenderTarget(0, render_target);
+
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        D3DCOLOR clear_col_dx = D3DCOLOR_RGBA((int)(clear_color.x*255.0f), (int)(clear_color.y*255.0f), (int)(clear_color.z*255.0f), (int)(clear_color.w*255.0f));
+        g_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, clear_col_dx, 1.0f, 0);
+    }
+
+    ImGui_ImplDX9_RenderDrawData(viewport->DrawData);
+
+    // Restore render target
+    g_pd3dDevice->SetRenderTarget(0, last_render_target);
+    render_target->Release();
+    last_render_target->Release();
+}
+
+static void ImGui_ImplDX9_SwapBuffers(ImGuiViewport* viewport, void*)
+{
+    ImGuiViewportDataDx9* data = (ImGuiViewportDataDx9*)viewport->RendererUserData;
+    data->SwapChain->Present(NULL, NULL, data->d3dpp.hDeviceWindow, NULL, NULL);
+}
+
+static void ImGui_ImplDX9_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_CreateWindow = ImGui_ImplDX9_CreateWindow;
+    platform_io.Renderer_DestroyWindow = ImGui_ImplDX9_DestroyWindow;
+    platform_io.Renderer_SetWindowSize = ImGui_ImplDX9_SetWindowSize;
+    platform_io.Renderer_RenderWindow = ImGui_ImplDX9_RenderWindow;
+    platform_io.Renderer_SwapBuffers = ImGui_ImplDX9_SwapBuffers;
+}
+
+static void ImGui_ImplDX9_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}

examples/imgui_impl_dx9.h

@@ -3,6 +3,7 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'LPDIRECT3DTEXTURE9' as ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
+//  [X] Renderer: Multi-viewport support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 
 // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this.
 // If you are new to dear imgui, read examples/README.txt and read the documentation at the top of imgui.cpp.