[astrange]

OpenGL isn't friendly to developers on either side. Tutorials are generally not trustworthy, there's no cross platform debugging tools, and errors just get you a "something happened vOv" code.

If you care about performance it will just do something slow at uncontrollable points in the background, like copy CPU-GPU-CPU memory, synchronize against the GPU, do format conversions, etc.

If you're the one implementing GL, it's gotten gigantic again since they simplified it. GL 4.3/4.6 core has compute shaders, which means you have to implement OpenCL twice but different this time.