Examples: OpenGL3+GLFW/SDL: Made main.cpp compile with IMGUI_IMPL_OPENGL_LOADER_CUSTOM (may be missing init). (#2178)

docs/CHANGELOG.txt

@@ -79,6 +79,7 @@ Other Changes:
 - Examples: DirectX10, DirectX11: Removed seemingly unnecessary calls to invalidate and recreate device objects
   in the WM_SIZE handler. (#2088) [@ice1000]
 - Examples: OpenGL3+GLFW: Fixed error condition when using the GLAD loader. (#2157) [@blackball]
+- Examples: OpenGL3+GLFW/SDL: Made main.cpp compile with IMGUI_IMPL_OPENGL_LOADER_CUSTOM (may be missing init). (#2178) [@doug-moen]
 
 
 -----------------------------------------------------------------------

examples/example_glfw_opengl3/main.cpp

@@ -73,6 +73,8 @@ int main(int, char**)
     bool err = glewInit() != GLEW_OK;
 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
     bool err = gladLoadGL() == 0;
+#else
+    bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.
 #endif
     if (err)
     {

examples/example_sdl_opengl3/main.cpp

@@ -65,6 +65,8 @@ int main(int, char**)
     bool err = glewInit() != GLEW_OK;
 #elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
     bool err = gladLoadGL() == 0;
+#else
+    bool err = false; // If you use IMGUI_IMPL_OPENGL_LOADER_CUSTOM, your loader is likely to requires some form of initialization.
 #endif
     if (err)
     {