1. We can now support calls like "glLight(..., ..., FloatBuffer.wrap(new float[] {...}));" without worrying about running out of direct memory heap,
since both the FloatBuffer and the array are allocated on the java heap. Future JVMs with stack allocation support could improve this even further.
2. We avoid getting in the way of users that doesn't (yet) know why direct buffers are important.
Obviously, we'd like direct support for arrays, but non-direct buffers are a nice compromise that avoids the API bloat that results when almost all
functions gain an overloaded versions that take arrays instead of buffers.
Notes:
1. Non-direct buffer support should not affect the performance in the direct buffer case, since the non-direct buffer code path is only activated
when the isDirect() check fails, and we were already checking isDirect() for sanity checking.
2. When using non-direct buffers, the buffer contents (remaining() bytes) are copied to a resizable ThreadLocal cached direct buffer (which is
resized as needed) and used instead of the non-direct buffer. Thus, performance of non-direct buffers is lower than direct buffers.