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student    : rwsu
graded by  : Damian Isla
problem set: ivscan
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Renders 1st test (triangle)   (0-3): 1
Renders 2nd test (rgb)        (0-2): 0.5
Renders 3rd test (cube)       (0-2): 0
Renders 4th test (interpen)   (0-2): 1
Renders 5th test (ellipse)    (0-2): 1
Renders 6th test (geekball)   (0-2): 1
Exactitude                    (0-2): 2
total                        (0-15): 6.5
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notes:

Your renderer unfortunately has some severe problems. It crashed on
most of the examples we tested it on. Those that don't crash display
results which are, well, pretty wrong.

It seems the problem with the crashing is due to the fact that you're
removing lines at the wrong time. When this happens, you end up with
only one edge for a certain polygon in the active edge list, and then
the AEL throws an exception when you try and find the "NextPolyEdge".

There were other problems, of varying severity. You interpolated Z
rather than h, as you should have. Also, the starting values of X
should have been adjusted (i.e. xcurr != xstart, initially) to account
for the edges being off-pixel-center.

If you have questions, please e-mail me (naimad).

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