Viewport: Reorganized viewport enable flags. Both user + platform + renderer need to enable a flag. (#1542)

examples/directx10_example/main.cpp

@@ -115,7 +115,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplWin32_Init(hwnd);

examples/directx11_example/main.cpp

@@ -118,7 +118,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplWin32_Init(hwnd);

examples/directx12_example/main.cpp

@@ -289,7 +289,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplWin32_Init(hwnd);

examples/imgui_impl_dx10.cpp

@@ -479,7 +479,8 @@ bool    ImGui_ImplDX10_Init(ID3D10Device* device)
     ImGuiIO& io = ImGui::GetIO();
     g_pd3dDevice = device;
     g_pFactory = pFactory;
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_RendererHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplDX10_InitPlatformInterface();
     return true;
 }

examples/imgui_impl_dx11.cpp

@@ -487,7 +487,8 @@ bool    ImGui_ImplDX11_Init(ID3D11Device* device, ID3D11DeviceContext* device_co
     g_pd3dDevice = device;
     g_pd3dDeviceContext = device_context;
     g_pFactory = pFactory;
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_RendererHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplDX11_InitPlatformInterface();
     return true;
 }

examples/imgui_impl_dx12.cpp

@@ -605,7 +605,8 @@ bool ImGui_ImplDX12_Init(ID3D12Device* device, int num_frames_in_flight, DXGI_FO
     }
 
     ImGuiIO& io = ImGui::GetIO();
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_RendererHasViewports; // FIXME-VIEWPORT: Actually unfinshed..
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplDX12_InitPlatformInterface();
 
     return true;

examples/imgui_impl_glfw.cpp

@@ -153,7 +153,8 @@ bool ImGui_ImplGlfw_Init(GLFWwindow* window, bool install_callbacks)
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)g_Window;
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplGlfw_InitPlatformInterface();
 
     g_ClientApi = GlfwClientApi_OpenGL;

examples/imgui_impl_opengl3.cpp

@@ -45,7 +45,10 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     strcpy(g_GlslVersion, glsl_version);
     strcat(g_GlslVersion, "\n");
 
-    ImGui_ImplOpenGL3_InitPlatformInterface();
+    ImGuiIO& io = ImGui::GetIO();
+    io.ConfigFlags |= ImGuiConfigFlags_RendererHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
+        ImGui_ImplOpenGL3_InitPlatformInterface();
     return true;
 }
 

examples/imgui_impl_sdl2.cpp

@@ -149,8 +149,11 @@ bool    ImGui_ImplSDL2_Init(SDL_Window* window, void* sdl_gl_context)
     // Our mouse update function expect PlatformHandle to be filled for the main viewport
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)window;
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+#if SDL_VERSION_ATLEAST(2,0,4)
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplSDL2_InitPlatformInterface(window, sdl_gl_context);
+#endif
 
     return true;
 }
@@ -172,7 +175,6 @@ static void ImGui_ImplSDL2_UpdateMouse()
     io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
     io.MousePosViewport = 0;
     io.MouseHoveredViewport = 0;
-    io.ConfigFlags &= ~ImGuiConfigFlags_PlatformHasMouseHoveredViewport; // FIXME-VIEWPORT: We can't get this info properly with SDL, capture is messing up with SDL_WINDOW_MOUSE_FOCUS report and we'd need to handle _NoInputs
 
     int mx, my;
     Uint32 mouse_buttons = SDL_GetMouseState(&mx, &my);

examples/imgui_impl_vulkan.cpp

@@ -703,7 +703,8 @@ bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass rend
 
     ImGuiIO& io = ImGui::GetIO();
     ImGui_ImplVulkan_CreateDeviceObjects();
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_RendererHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplVulkan_InitPlatformInterface();
 
     return true;

examples/imgui_impl_win32.cpp

@@ -71,7 +71,8 @@ bool    ImGui_ImplWin32_Init(void* hwnd)
     ImGuiViewport* main_viewport = ImGui::GetMainViewport();
     main_viewport->PlatformHandle = (void*)g_hWnd;
 
-    if (io.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    io.ConfigFlags |= ImGuiConfigFlags_PlatformHasViewports;
+    if (io.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         ImGui_ImplWin32_InitPlatformInterface();
 
     return true;

examples/opengl3_example/main.cpp

@@ -35,7 +35,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;   // Enable Gamepad Controls
 

examples/sdl_opengl3_example/main.cpp

@@ -37,7 +37,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplSDL2_Init(window, gl_context);

examples/sdl_vulkan_example/main.cpp

@@ -344,7 +344,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplVulkan_InitInfo init_info = {};

examples/vulkan_example/main.cpp

@@ -353,7 +353,7 @@ int main(int, char**)
     // Setup ImGui binding
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
-    io.ConfigFlags |= ImGuiConfigFlags_MultiViewports;
+    io.ConfigFlags |= ImGuiConfigFlags_EnableViewports;
     //io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;  // Enable Keyboard Controls
 
     ImGui_ImplVulkan_InitInfo init_info = {};

imgui.cpp

@@ -3246,7 +3246,7 @@ static void ImGui::UpdateMovingWindowDropViewport(ImGuiWindow* window)
     // On release we either drop window over an existing viewport or create a new one
     // (We convert position from one viewport space to another, which is unnecessary at the moment but allows us to have viewport overlapping in term of imgui position)
     ImGuiContext& g = *GImGui;
-    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports))
+    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
         return;
 
     ImRect mouse_viewport_rect = g.MouseViewport->GetRect();
@@ -3386,11 +3386,11 @@ static void ImGui::UpdateViewports()
     ImGuiViewport* main_viewport = g.Viewports[0];
     IM_ASSERT(main_viewport->ID == IMGUI_VIEWPORT_DEFAULT_ID);
     ImVec2 main_viewport_os_desktop_pos = ImVec2(0.0f, 0.0f);
-    if ((g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports))
+    if ((g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
         main_viewport_os_desktop_pos = g.IO.PlatformInterface.GetWindowPos(main_viewport);
     Viewport(IMGUI_VIEWPORT_DEFAULT_ID, ImGuiViewportFlags_MainViewport, main_viewport_os_desktop_pos, g.IO.DisplaySize);
 
-    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports))
+    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
     {
         g.MouseViewport = g.MouseLastViewport = main_viewport;
         return;
@@ -3541,15 +3541,23 @@ void ImGui::NewFrame()
     if (g.IO.ConfigFlags & ImGuiConfigFlags_NavEnableKeyboard)
         IM_ASSERT(g.IO.KeyMap[ImGuiKey_Space] != -1 && "ImGuiKey_Space is not mapped, required for keyboard navigation.");
 
-    if (g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    if (g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports)
     {
+        if ((g.IO.ConfigFlags & ImGuiConfigFlags_PlatformHasViewports) && (g.IO.ConfigFlags & ImGuiConfigFlags_RendererHasViewports))
+        {
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-        IM_ASSERT(g.IO.RenderDrawListsFn == NULL);  // Call ImGui::Render() then pass ImGui::GetDrawData() yourself to your render function!
+            IM_ASSERT(g.IO.RenderDrawListsFn == NULL);  // Call ImGui::Render() then pass ImGui::GetDrawData() yourself to your render function!
 #endif
-        IM_ASSERT(g.IO.PlatformInterface.CreateViewport != NULL);
-        IM_ASSERT(g.IO.PlatformInterface.DestroyViewport != NULL);
-        //IM_ASSERT(g.IO.PlatformInterface.RenderViewport != NULL || g.IO.RendererInterface.RenderViewport != NULL);  // Missing rendering function
-        IM_ASSERT(g.Viewports[0]->PlatformUserData != NULL);        // Platform init function didn't setup main viewport
+            IM_ASSERT(g.IO.PlatformInterface.CreateViewport != NULL);
+            IM_ASSERT(g.IO.PlatformInterface.DestroyViewport != NULL);
+            //IM_ASSERT(g.IO.PlatformInterface.RenderViewport != NULL || g.IO.RendererInterface.RenderViewport != NULL);  // Missing rendering function
+            IM_ASSERT(g.Viewports[0]->PlatformUserData != NULL);        // Platform init function didn't setup main viewport
+        }
+        else
+        {
+            // Disable feature, our back-ends do not support it
+            g.IO.ConfigFlags &= ~ImGuiConfigFlags_EnableViewports;
+        }
     }
 
     // Load settings on first frame
@@ -4354,7 +4362,7 @@ void ImGui::EndFrame()
 
     g.FrameCountEnded = g.FrameCount;
 
-    if (g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    if (g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         UpdatePlatformWindows();
 }
 
@@ -4418,7 +4426,7 @@ void ImGui::Render()
 void ImGui::RenderAdditionalViewports()
 {
     ImGuiContext& g = *GImGui;
-    if (g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports)
+    if (g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports)
         RenderPlatformWindows();
 }
 
@@ -5908,7 +5916,7 @@ static void ImGui::UpdateWindowViewport(ImGuiWindow* window, bool window_pos_set
 
     // Restore main viewport if multi viewports are not supported by the back-end
     ImGuiViewport* main_viewport = g.Viewports[0];
-    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_MultiViewports))
+    if (!(g.IO.ConfigFlags & ImGuiConfigFlags_EnableViewports))
     {
         window->Viewport = main_viewport;
         window->ViewportId = main_viewport->ID;

imgui.h

@@ -772,18 +772,20 @@ enum ImGuiNavInput_
 enum ImGuiConfigFlags_
 {
     // Navigation
-    ImGuiConfigFlags_NavEnableKeyboard                  = 1 << 0,   // Master keyboard navigation enable flag. NewFrame() will automatically fill io.NavInputs[] based on io.KeyDown[].
-    ImGuiConfigFlags_NavEnableGamepad                   = 1 << 1,   // Master gamepad navigation enable flag. This is mostly to instruct your imgui back-end to fill io.NavInputs[].
+    ImGuiConfigFlags_NavEnableKeyboard                  = 1 << 0,   // Keyboard navigation enable flag. NewFrame() will automatically fill io.NavInputs[] based on io.KeyDown[].
+    ImGuiConfigFlags_NavEnableGamepad                   = 1 << 1,   // Gamepad navigation enable flag. This is mostly to instruct your imgui back-end to fill io.NavInputs[].
     ImGuiConfigFlags_NavMoveMouse                       = 1 << 2,   // Request navigation to allow moving the mouse cursor. May be useful on TV/console systems where moving a virtual mouse is awkward. Will update io.MousePos and set io.WantMoveMouse=true. If enabled you MUST honor io.WantMoveMouse requests in your binding, otherwise ImGui will react as if the mouse is jumping around back and forth.
     ImGuiConfigFlags_NavNoCaptureKeyboard               = 1 << 3,   // Do not set the io.WantCaptureKeyboard flag with io.NavActive is set. 
 
     // [BETA] Viewports
-    ImGuiConfigFlags_MultiViewports                     = 1 << 4,   // User enable multiple viewports (require io.PlatformInterface + io.RendererInterface)
-    ImGuiConfigFlags_PlatformHasMouseHoveredViewport    = 1 << 5,   // Back-end knows how to set io.MouseHoveredViewport to the viewport directly under the mouse _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag and _REGARDLESS_ of whether another viewport is focused and may have mouse capture. This info is not easy to provide correctly with most high-level engines.
-    ImGuiConfigFlags_PlatformHasWantMoveMouseSupport    = 1 << 6,   // Back-end honors io.WantMoveMouse request by updating the OS mouse cursor position (currently only used by ImGuiConfigFlags_NavMoveMouse feature, will be useful for widgets teleporting/wrapping the cursor)
-    ImGuiConfigFlags_PlatformHasWindowAlpha             = 1 << 7,   // Back-end can have transparent windows
+    ImGuiConfigFlags_EnableViewports                    = 1 << 4,   // Viewport enable flags (require both ImGuiConfigFlags_PlatformHasViewports + ImGuiConfigFlags_RendererHasViewports set by the respective back-ends)
+    ImGuiConfigFlags_PlatformHasViewports               = 1 << 5,   // Back-end Platform supports multiple viewports
+    ImGuiConfigFlags_PlatformHasMouseHoveredViewport    = 1 << 6,   // Back-end Platform supports setting io.MouseHoveredViewport to the viewport directly under the mouse _IGNORING_ viewports with the ImGuiViewportFlags_NoInputs flag and _REGARDLESS_ of whether another viewport is focused and may be capturing the mouse. This information is _NOT EASY_ to provide correctly with most high-level engines. Don't see this without studying how the examples/ back-end handle it.
+    ImGuiConfigFlags_PlatformHasWantMoveMouseSupport    = 1 << 7,   // Back-end Platform supports io.WantMoveMouse request by updating the OS mouse cursor position (currently only used by ImGuiConfigFlags_NavMoveMouse feature, will be useful for widgets teleporting/wrapping the cursor)
+    ImGuiConfigFlags_PlatformHasWindowAlpha             = 1 << 8,   // Back-end Platform supports transparent windows
+    ImGuiConfigFlags_RendererHasViewports               = 1 << 9,   // Back-end Renderer supports multiple viewports
     
-    // Platform Info (strictly for the user/application)
+    // Platform Info (free of use, for user/application convenience)
     ImGuiConfigFlags_IsSRGB                             = 1 << 10,  // Back-end is SRGB-aware (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
     ImGuiConfigFlags_IsTouchScreen                      = 1 << 11,  // Back-end is using a touch screen instead of a mouse (Storage flag to allow your back-end to communicate to shared widgets. Not used by core ImGui)
     ImGuiConfigFlags_IsOnScreenKeyboard                 = 1 << 12   // Back-end uses an on-screen keyboard when io.WantTextInput is set.