Too many asserts

[MutexMakhano]

Usually in programs, if something is wrong with the input data, you can return an error code. Instead this library program uses assert() all over the place, which if left in will stop the program, if removed will leave it in a corrupted state. As a caller, I have no idea how to stop it doing this.
A library like this cannot be trusted if it will take down the program calling it. I have chucked all sorts of rubbish data at the GLU tesselator in my time and it has never crashed.

[sfreilich]

You're right, but what are you trying to achieve in opening this issue? If you're trying to get agreement that the code could be improved, mission accomplished, but that's the easy part, please include tests with your change. If you're trying to convince someone else to do so, there hasn't been a lot of spare capacity to make changes to this library. If you're trying to point out some specific problem you've run into using this library in practice, you could be more specific.