plutovg VS tigr

Sub-pixel positioned anti-aliased lines and dots are simple. Extending that idea to drawing any shape is far more fiddly. I found this excellent rasteriser and this article which explains how it works. PlutoVG wraps that rasteriser in an easy-to-use API. I'm very happy with the results.

TIGR

I think Tigr is probably the easiest plug-and-play solution. But if I don't need moving or interactive graphics, I usually just output SVG images (no library needed).

reminds me of TIGR, but simpler (but also without hardware acceleration/shaders, but also with sound)

Delighful, works at first try and the code looks well organized.

    git clone https://github.com/erkkah/tigr.git

In addition to the other options, you can look at small windowing libraries in other languages. For example TIGR has pretty straightforward Mac code using pure C (you'll need to have some understanding of the ObjC object model and the way it's exposed to C though).

I found TIGR to be the most pain-free way to just get graphics on the screen. It includes basic shape and font rendering.

I've found that the quickest and simplest solution to render graphics is Tigr.