Backends: OpenGL3: Attempt to automatically detect default GL loader by using __has_include. Followup to 44cd8e3 (#2798)

This commit is contained in:
omar
2019-09-22 23:19:04 +02:00
parent 44cd8e39da
commit 97691643b7
5 changed files with 70 additions and 35 deletions

View File

@ -1,5 +1,5 @@
// dear imgui: Renderer for modern OpenGL with shaders / programmatic pipeline
// - Desktop GL: 3.x 4.x
// - Desktop GL: 2.x 3.x 4.x
// - Embedded GL: ES 2.0 (WebGL 1.0), ES 3.0 (WebGL 2.0)
// This needs to be used along with a Platform Binding (e.g. GLFW, SDL, Win32, custom..)
@ -23,37 +23,42 @@
#pragma once
// Specific OpenGL versions
//#define IMGUI_IMPL_OPENGL_ES2 // Auto-detected on Emscripten
//#define IMGUI_IMPL_OPENGL_ES3 // Auto-detected on iOS/Android
// Set default OpenGL3 loader to be gl3w
#if !defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
// to avoid problem with non-clang compilers not having this macro.
#if defined(__has_include)
// check if the header exists, then automatically define the macros ..
#if __has_include(<GL/glew.h>)
#define IMGUI_IMPL_OPENGL_LOADER_GLEW
#elif __has_include(<glad/glad.h>)
#define IMGUI_IMPL_OPENGL_LOADER_GLAD
#else
#define IMGUI_IMPL_OPENGL_LOADER_GL3W
#endif
#else
#define IMGUI_IMPL_OPENGL_LOADER_GL3W
#endif
#endif
// Backend API
IMGUI_IMPL_API bool ImGui_ImplOpenGL3_Init(const char* glsl_version = NULL);
IMGUI_IMPL_API void ImGui_ImplOpenGL3_Shutdown();
IMGUI_IMPL_API void ImGui_ImplOpenGL3_NewFrame();
IMGUI_IMPL_API void ImGui_ImplOpenGL3_RenderDrawData(ImDrawData* draw_data);
// Called by Init/NewFrame/Shutdown
// (Optional) Called by Init/NewFrame/Shutdown
IMGUI_IMPL_API bool ImGui_ImplOpenGL3_CreateFontsTexture();
IMGUI_IMPL_API void ImGui_ImplOpenGL3_DestroyFontsTexture();
IMGUI_IMPL_API bool ImGui_ImplOpenGL3_CreateDeviceObjects();
IMGUI_IMPL_API void ImGui_ImplOpenGL3_DestroyDeviceObjects();
// Specific OpenGL versions
//#define IMGUI_IMPL_OPENGL_ES2 // Auto-detected on Emscripten
//#define IMGUI_IMPL_OPENGL_ES3 // Auto-detected on iOS/Android
// Desktop OpenGL: attempt to detect default GL loader based on available header files.
// If auto-detection fails or doesn't select the same GL loader file as used by your application,
// you are likely to get a crash in ImGui_ImplOpenGL3_Init().
// You can explicitly select a loader by using '#define IMGUI_IMPL_OPENGL_LOADER_XXX' in imconfig.h or compiler command-line.
#if !defined(IMGUI_IMPL_OPENGL_LOADER_GL3W) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_GLEW) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_GLAD) \
&& !defined(IMGUI_IMPL_OPENGL_LOADER_CUSTOM)
#if defined(__has_include)
#if __has_include(<GL/glew.h>)
#define IMGUI_IMPL_OPENGL_LOADER_GLEW
#elif __has_include(<glad/glad.h>)
#define IMGUI_IMPL_OPENGL_LOADER_GLAD
#elif __has_include(<GL/gl3w.h>)
#define IMGUI_IMPL_OPENGL_LOADER_GL3W
#else
#error "Cannot detect OpenGL loader!"
#endif
#else
#define IMGUI_IMPL_OPENGL_LOADER_GL3W // Default to GL3W
#endif
#endif