1 files changed, 41 insertions, 1 deletions
diff --git a/3rdparty/imgui/source/backends/imgui_impl_opengl3.cpp b/3rdparty/imgui/source/backends/imgui_impl_opengl3.cpp
index 93f057d..1c8425b 100644
--- a/3rdparty/imgui/source/backends/imgui_impl_opengl3.cpp
+++ b/3rdparty/imgui/source/backends/imgui_impl_opengl3.cpp
@@ -9,6 +9,7 @@
 
 // Implemented features:
 //  [X] Renderer: User texture binding. Use 'GLuint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID!
+//  [X] Renderer: Multi-viewport support. Enable with 'io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable'.
 //  [x] Renderer: Desktop GL only: Support for large meshes (64k+ vertices) with 16-bit indices.
 
 // You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
@@ -18,6 +19,7 @@
 
 // CHANGELOG
 // (minor and older changes stripped away, please see git history for details)
+//  2022-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
 //  2021-12-15: OpenGL: Using buffer orphaning + glBufferSubData(), seems to fix leaks with multi-viewports with some Intel HD drivers.
 //  2021-08-23: OpenGL: Fixed ES 3.0 shader ("#version 300 es") use normal precision floats to avoid wobbly rendering at HD resolutions.
 //  2021-08-19: OpenGL: Embed and use our own minimal GL loader (imgui_impl_opengl3_loader.h), removing requirement and support for third-party loader.
@@ -197,7 +199,7 @@ struct ImGui_ImplOpenGL3_Data
     GLsizeiptr      IndexBufferSize;
     bool            HasClipOrigin;
 
-    ImGui_ImplOpenGL3_Data() { memset(this, 0, sizeof(*this)); }
+    ImGui_ImplOpenGL3_Data() { memset((void*)this, 0, sizeof(*this)); }
 };
 
 // Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
@@ -207,6 +209,10 @@ static ImGui_ImplOpenGL3_Data* ImGui_ImplOpenGL3_GetBackendData()
     return ImGui::GetCurrentContext() ? (ImGui_ImplOpenGL3_Data*)ImGui::GetIO().BackendRendererUserData : NULL;
 }
 
+// Forward Declarations
+static void ImGui_ImplOpenGL3_InitPlatformInterface();
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface();
+
 // Functions
 bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
 {
@@ -248,6 +254,7 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     if (bd->GlVersion >= 320)
         io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
 #endif
+    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)
 
     // Store GLSL version string so we can refer to it later in case we recreate shaders.
     // Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
@@ -285,6 +292,9 @@ bool    ImGui_ImplOpenGL3_Init(const char* glsl_version)
     }
 #endif
 
+    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        ImGui_ImplOpenGL3_InitPlatformInterface();
+
     return true;
 }
 
@@ -294,6 +304,7 @@ void    ImGui_ImplOpenGL3_Shutdown()
     IM_ASSERT(bd != NULL && "No renderer backend to shutdown, or already shutdown?");
     ImGuiIO& io = ImGui::GetIO();
 
+    ImGui_ImplOpenGL3_ShutdownPlatformInterface();
     ImGui_ImplOpenGL3_DestroyDeviceObjects();
     io.BackendRendererName = NULL;
     io.BackendRendererUserData = NULL;
@@ -543,6 +554,7 @@ bool ImGui_ImplOpenGL3_CreateFontsTexture()
     io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height);   // Load as RGBA 32-bit (75% of the memory is wasted, but default font is so small) because it is more likely to be compatible with user's existing shaders. If your ImTextureId represent a higher-level concept than just a GL texture id, consider calling GetTexDataAsAlpha8() instead to save on GPU memory.
 
     // Upload texture to graphics system
+    // (Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling)
     GLint last_texture;
     glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
     glGenTextures(1, &bd->FontTexture);
@@ -810,6 +822,34 @@ void    ImGui_ImplOpenGL3_DestroyDeviceObjects()
     ImGui_ImplOpenGL3_DestroyFontsTexture();
 }
 
+//--------------------------------------------------------------------------------------------------------
+// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
+// This is an _advanced_ and _optional_ feature, allowing the backend 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..
+//--------------------------------------------------------------------------------------------------------
+
+static void ImGui_ImplOpenGL3_RenderWindow(ImGuiViewport* viewport, void*)
+{
+    if (!(viewport->Flags & ImGuiViewportFlags_NoRendererClear))
+    {
+        ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
+        glClearColor(clear_color.x, clear_color.y, clear_color.z, clear_color.w);
+        glClear(GL_COLOR_BUFFER_BIT);
+    }
+    ImGui_ImplOpenGL3_RenderDrawData(viewport->DrawData);
+}
+
+static void ImGui_ImplOpenGL3_InitPlatformInterface()
+{
+    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
+    platform_io.Renderer_RenderWindow = ImGui_ImplOpenGL3_RenderWindow;
+}
+
+static void ImGui_ImplOpenGL3_ShutdownPlatformInterface()
+{
+    ImGui::DestroyPlatformWindows();
+}
+
 #if defined(__clang__)
 #pragma clang diagnostic pop
 #endif