SDL2 doesn't have the right primitives for easy dear imgui use; there's no renderer-agnostic support for drawing arbitrary textured triangle lists. So you have to get right in there and do your own drawing, which is (depending on renderer) anything from straightforward (and SDL will even give you a hand) to tiresome.

There's a longstanding sporadically-updated fork of SDL that kind of fixes this, but it's something that the SDL team don't seem to have much interest in. See https://bugzilla.libsdl.org/show_bug.cgi?id=1734

That might be a good idea. I hadn't thought of SDL which would provide a bare minimum to get cross platform.

Here is a writeup from someone trying to get SDL to work with Dear ImGui. It kind of works, but...

https://retifrav.github.io/blog/2019/05/26/sdl-imgui/

You can feel this persons frustration about all the obscure magic incantations needed to get a simple GUI and some lines on screen. The really awful part is the last bits where he discusses how to get the damn thing compiled on Win/Linux/Mac. Even installing all the needed bits is an ordeal. Only a masochist would love this - which to be fair, probably describes game developers as a group.

The real question is why is this so hard? Or rather why does this require so much random obscure knowledge in this day and age? And all of this is so ridiculously brittle. You're one OS upgrade from the whole thing falling apart either on the build side or on the user side.

That's why people today just write HTML/JavaScript browser GUI for whatever they're doing and call it a day. It's way easier.

> You can feel this persons frustration about all the obscure magic incantations needed to get a simple GUI and some lines on screen.

The vast majority is setting up SDL with a graphics context - anything graphics in C++ land is notoriously tedious, yes - not much of that is in control of Dear ImGui.

If you look at "Plugging Dear ImGui into SDL" there's a total of 14 lines involved in adding Dear ImGui over an existing SDL+OpenGL application, which is the precise target use of Dear Imgui.

Here are the lines:

  // Init
  IMGUI_CHECKVERSION();
  ImGui::CreateContext();
  ImGui::StyleColorsDark();
  ImGui_ImplSDL2_InitForOpenGL(window, gl_context);
  ImGui_ImplOpenGL3_Init(glsl_version.c_str());

  // Event forwarding
  ImGui_ImplSDL2_ProcessEvent(&event);

  // New frame
  ImGui_ImplOpenGL3_NewFrame();
  ImGui_ImplSDL2_NewFrame(window);
  ImGui::NewFrame();

  // Rendering
  ImGui::Render();
  ImGui_ImplOpenGL3_RenderDrawData(ImGui::GetDrawData());

  // Shutdown
  ImGui_ImplOpenGL3_Shutdown();
  ImGui_ImplSDL2_Shutdown();
  ImGui::DestroyContext();

Everything else is setup that has nothing to do with dear imgui, or excess dear imgui usage demo from that article. I'm not sure it's possible to make it any easier other that adding a wrapper across all back-ends.

Yes, setting up graphics stuff in C++ is not trivial, but that's not Dear ImGui fault.

> Only a masochist would love this - which to be fair, probably describes game developers as a group.

Yes. Game developers are people who can have GTA5 running on a PS3, a console with 256x2 MB of RAM, while web applications displaying a chat frequently use more memory than that. I guess you call it masochist, I call it being efficient and excellent.

https://www.youtube.com/watch?v=d0KJhFMnWRI