feat: implement an ImGui layer

1 files changed, 62 insertions, 0 deletions

diff --git a/src/core/window.cpp b/src/core/window.cpp
index f598357..df19b86 100644
--- a/src/core/window.cpp
+++ b/src/core/window.cpp
@@ -2,6 +2,10 @@
 
 #include <cstdint>
 
+#include <imgui.h>
+#include <imgui_impl_glfw.h>
+#include <imgui_impl_opengl3.h>
+
 namespace Donut
 {
     static bool     s_glfw_initialized = false;
@@ -66,6 +70,9 @@ namespace Donut
     void Window::shutdown()
     {
         DONUT_INFO("Shutting down window: ", m_title);
+        
+        shutdown_im_gui();
+        
         glfwDestroyWindow(m_window);
         s_glfw_window_count--;
 
@@ -102,6 +109,61 @@ namespace Donut
                          GLFW_CURSOR_NORMAL : GLFW_CURSOR_HIDDEN);
     }
 
+    void Window::init_im_gui()
+    {
+        IMGUI_CHECKVERSION();
+        ImGui::CreateContext();
+        ImGuiIO& io = ImGui::GetIO();
+        io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;
+        io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;
+        io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;
+
+        ImGui::StyleColorsDark();
+
+        ImGuiStyle& style = ImGui::GetStyle();
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            style.WindowRounding = 0.0f;
+            style.Colors[ImGuiCol_WindowBg].w = 1.0f;
+        }
+
+        ImGui_ImplGlfw_InitForOpenGL(m_window, true);
+        ImGui_ImplOpenGL3_Init("#version 130");
+        
+        DONUT_INFO("ImGUI initialized successfully");
+    }
+
+    void Window::shutdown_im_gui()
+    {
+        ImGui_ImplOpenGL3_Shutdown();
+        ImGui_ImplGlfw_Shutdown();
+        ImGui::DestroyContext();
+        
+        DONUT_INFO("ImGUI shutdown");
+    }
+
+    void Window::begin_im_gui_frame()
+    {
+        ImGui_ImplOpenGL3_NewFrame();
+        ImGui_ImplGlfw_NewFrame();
+        ImGui::NewFrame();
+    }
+
+    void Window::end_im_gui_frame()
+    {
+        ImGui::Render();
+        ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());
+
+        ImGuiIO& io = ImGui::GetIO();
+        if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
+        {
+            GLFWwindow* backup_current_context = glfwGetCurrentContext();
+            ImGui::UpdatePlatformWindows();
+            ImGui::RenderPlatformWindowsDefault();
+            glfwMakeContextCurrent(backup_current_context);
+        }
+    }
+
     void Window::glfw_error_callback(int error, const char* description)
     {
         DONUT_ERROR("GLFW Error (", error, "): ", description);