imgui/examples/imgui_impl_opengl3.h

// ImGui Renderer for: OpenGL3 (modern OpenGL with shaders / programmatic pipeline)
// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
// (Note: We are using GL3W as a helper library to access OpenGL functions since there is no standard header to access modern OpenGL functions easily. Alternatives are GLEW, Glad, etc..)

// Implemented features:
//  [X] User texture binding. Use 'GLUint' OpenGL texture identifier as void*/ImTextureID. Read the FAQ about ImTextureID in imgui.cpp.
//  [X] Multi-viewport rendering (when ImGuiConfigFlags_EnableViewports is enabled).

IMGUI_API bool  ImGui_ImplOpenGL3_Init(const char* glsl_version = NULL);
IMGUI_API void  ImGui_ImplOpenGL3_Shutdown();
IMGUI_API void  ImGui_ImplOpenGL3_NewFrame();
IMGUI_API void  ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);

// Called by Init/NewFrame/Shutdown
IMGUI_API bool  ImGui_ImplOpenGL3_CreateFontsTexture();
IMGUI_API void  ImGui_ImplOpenGL3_DestroyFontsTexture();
IMGUI_API bool  ImGui_ImplOpenGL3_CreateDeviceObjects();
IMGUI_API void  ImGui_ImplOpenGL3_DestroyDeviceObjects();