A developer called Michael Gerdes just published a MiniGolf game on GitHub. This uses OpenGL for the graphiocs and according to GitHub is made up of

• C 76.5%
• C++21.4%
• GLSL 0.8%
• Scheme 0.7%
• Objective-C 0.6%
• HTML 0.0%

Every project on GitHub has these on the RHS of the home page. They include links with filters to see the particular set of files. Particularly telling is GLSL which are shaders. If you do 3D graphics, that’s something you need to learn. Its why I stick to 2D. The other stuff probably comes as part of various linked libraries.

It’s nicely done and the GitHub page has four animated gifs showing how it works. It also uses the open source Dear Imgui GUI library.