The reason I kept the minimum OpenGL 3.3 requirement is because it is supported on the biggest range of platforms. OpenGL 4.xx features require some features from newer generation cards. Of course, with time this is becoming less and less relevant.
In some parts of the code, I did make use of OpenGL 4.xx features like glMultiDrawIndirect, but this is put behind a check to see if it's supported by the driver and added a slower fallback for OpenGL 3.3.
Why didn't you directly use SDL for rendering instead of OpenGL?
Was it for performance reasons?
OpenGL is deprecated on mac, and SDL use Vulkan on Window and Linux which I guess is better, performance wise than OpenGL.
SDL gives you an API for 2D rendering, mostly limited to drawing boxes, lines, and bitmaps. OpenGL lets you program the graphics card for any use case, most commonly 3D graphics with room to add complex effects and post-processing. The SDL API is just nowhere near flexible enough for what I want to achieve.
Plus, Vulkan is not really "faster" than OpenGL. It just gives you a different API for programming the same graphics hardware, which in the hands of the right person can be used for writing code which is "faster".
That's a very reasonable approach and what I would typically do at work.
I guess my surprise was mainly because it's the kind of extra bother I personally like to get away from in my personal projects. Then again, I typically don't write things meant for adoption by a wide audience. Kudos for making the necessary effort.
In some parts of the code, I did make use of OpenGL 4.xx features like glMultiDrawIndirect, but this is put behind a check to see if it's supported by the driver and added a slower fallback for OpenGL 3.3.