Subject: memory leaks

(This message is being sent to CPSC 215 Students and TA's)

I have noticed that many sp6 programs are leaking memory in a
big way. Since only 4 rays are fired in sp6, there is no ill
effect of the leak and since we haven't discussed this much in
class, I will not penalize it on sp6.

These leaks MUST be corrected in the ray tracer.

The basic rules that should be followed are:

(1) things malloc'ed in projection_init/model_init need
    to exist until the program ends and should NOT BE FREED

(2) for every other instance of malloc() there MUST be
    a corresponding free() IN THE FUNCTION in which the
    malloc() occurs.

(3) a better option is to change all malloc() EXCEPT THOSE
    in projection_init/model_init to alloca()  The
    alloca() function allocates small amounts of storage
    on the stack and it does not require the use of free()
    to release the storage. In fact attempting to free()
    storage allocated with alloca() is a FATAL ERROR.

More on this in class monday.