lecture_viewing3d - Mesh & GL_ELEMENT_ARRAY_BUFFER

[RobertLeahy]

In lecture_viewing3d, in the Mesh::init method on line 61 a buffer object is bound to the GL_ELEMENT_ARRAY_BUFFER target. This is never undone, nor is it redone in Mesh::draw.

By sheer chance nothing else is ever bound to this target so the code works, but if anyone uses this as a baseline/reference for anything in a more complicated system they're probably going to have quite the time finding the bug.

[taiya]

Thanks Robert, the same will be true for a number of other calls :)
Our example code is not very rigorous in terms of memory clean-up and buffer unbinding.

A much better way of doing this would be by implementing a class that unbinds when the object falls out of scope. But in previous years students complained that by giving them a game-engine like framework they didn't learn anything of OpenGL. That's why the code it's the way it is now. It's a compromise!