README.md updated with backend_test info

README.md

@@ -26,6 +26,8 @@ Notes:
   * using makefile on linux/macOS/mingw (Or use CMake to generate project)
   * cmake options are IMGUI_STATIC (compiling as static library), IMGUI_FREETYPE (for using Freetype2) and FREETYPE_PATH (Freetype2 cmake install location)
   * or as in https://github.com/sonoro1234/LuaJIT-ImGui/tree/master/build
+  
+  For compiling with backends there is now an example with SDL2 and opengl3 in folder backend_test. It will generate a cimgui_sdl module and a test_sdl executable. You only need to provide SDL_PATH telling cmake where to look for SDL2 cmake installation.
 
 # using generator
 
@@ -86,6 +88,10 @@ Notes:
 * functions that belong to a struct have an extra first argument with a pointer to the struct.
 * where a function returns UDT (user defined type) by value some compilers complain so the function is generated accepting a pointer to the UDT type as the first argument (or second if belongs to a struct).
 
+# usage with backends
+
+* look at backend_test folder for a cmake module building with SDL and opengl3.
+
 # example bindings based on cimgui
 
 * [LuaJIT-ImGui](https://github.com/sonoro1234/LuaJIT-ImGui)

backend_test/main.c

@@ -79,9 +79,10 @@ int main(int argc, char* argv[])
   ImGuiIO* ioptr = igGetIO();
   ioptr->ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;       // Enable Keyboard Controls
   //ioptr->ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
+#ifdef ImGuiConfigFlags_DockingEnable
   ioptr->ConfigFlags |= ImGuiConfigFlags_DockingEnable;           // Enable Docking
   ioptr->ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;         // Enable Multi-Viewport / Platform Windows
-  
+#endif
   
   ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
   ImGui_ImplOpenGL3_Init(glsl_version);
@@ -167,7 +168,7 @@ int main(int argc, char* argv[])
     glClearColor(clearColor.x, clearColor.y, clearColor.z, clearColor.w);
     glClear(GL_COLOR_BUFFER_BIT);
     ImGui_ImplOpenGL3_RenderDrawData(igGetDrawData());
-	
+#ifdef ImGuiConfigFlags_DockingEnable
 	if (ioptr->ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
         {
             SDL_Window* backup_current_window = SDL_GL_GetCurrentWindow();
@@ -176,7 +177,7 @@ int main(int argc, char* argv[])
             igRenderPlatformWindowsDefault(NULL,NULL);
             SDL_GL_MakeCurrent(backup_current_window, backup_current_context);
         }
-	
+#endif
     SDL_GL_SwapWindow(window);
   }