OpenGL 1.x is ancient and unless you're targeting very old hardware for some retro project, you wouldn't use it, but the link you provided says it could run ImGui.

Also SDL1 seems completely irrelevant?

Yup, it seems it could work for both SDL1 and OpenGL 1.x, it's just a matter of writing a custom backend. Per README:

"Integrating Dear ImGui within your custom engine is a matter of 1) wiring mouse/keyboard/gamepad inputs 2) uploading one texture to your GPU/render engine 3) providing a render function that can bind textures and render textured triangles."

The backends don't seem all that complicated. Here's the OpenGL 2 implementation: https://github.com/ocornut/imgui/blob/master/backends/imgui_... - should be backportable to OpenGL 1.x.

I'm pretty sure that if someone was crazy enough, they could even write a ncurses backend for it. Rejecting 50% of the functionality for sure, but most of the UIs I've seen done with Dear ImGui were simple enough that they could be translated to terminal display almost 1:1.

I actually love this kind of design, where the dependency on IO particulars is neatly separated out. I don't see much in terms of automated testing in the repo, but I imagine feature-level tests should be easy to add with such design: just have a backend that lets the test drive input, and consume callbacks and rendering commands.

By the way, that link is broken because of a following character being parsed by HN as being part of the URL.

Thanks, fixed.

@dang, is there any reason URL parser should consider a trailing semicolon to be a part of the URL? Or maybe HN needs some form of minimal markup or escaping syntax for URLs? Or at least a documentation of the existing parser? :).

Here's an experimental text-mode backend for Dear ImGui based on ncurses (not sure if this required deeper changes to Dear ImGui though):

https://github.com/ggerganov/imtui

Also, regarding automated testing, AFAIK this is in progress for quite a while:

https://github.com/ocornut/imgui/issues/435

You could write an OpenGL 1.x backend for Dear ImGui (ImGui "officially" doesn't come with any rendering backends, although the example backends can be considered "semi-offical").

All that's needed for GL 1.x is to convert the vertex- and index-data you're getting from ImGui into triangle glBegin/End call sequences. But what's the point when all relevant platforms support at least OpenGL 2.x for at least a (more like two) decade(s)?

I built it, along with a long (long!) detour to build glslc, which AFAICT Debian does not package although it does package libglslang.a (!?).

The CMake find_program thing was utterly unable to find glslc, even when I placed it in /usr/bin/; I had to hand-edit the build/CMakeCache.txt entry. (^*%^&^$%&% CMake.)

When run, it pops up a window frame for a fractional second and dies with "VulkanInstance: no physical device". Otherwise, nice!

> AFAICT Debian does not package although it does package libglslang.a (!?)

Well, those are different projects. The standalone version of libglslang is glslangValidator.

> The CMake find_program thing was utterly unable to find glslc, even when I placed it in /usr/bin/; I had to hand-edit the build/CMakeCache.txt entry. (^*%^&^$%&% CMake.)

I checked and the CMake code in this project is wrong:

https://cmake.org/cmake/help/latest/command/find_program.htm...

it should be

    find_program(GLSLC_PATH glslc REQUIRED FATAL_ERROR)

e.g. here it was calling find_program with "glslc" as variable name in which to put a program called ""

I submitted a fix here: https://github.com/cledant/scop_vulkan/pull/1

Welcome to dependency hell

Awesome example, bookmarked!

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