S2K Arial, Bold, 37 points, 105% line spacing

Extra Credit (cont.)

4. Extend the interface to allow the input of polygons with “curved” boundaries. Curve is approximated by lots of closely spaced vertices that are still linearly connected. Not too tough, add vertices along mouse path while mouse button is down.

5. Combine #3 and #4 to allow different curved boundaries for each keyframe. Calculate approximate locations for vertices when the number changes. For example, going from a curve with 10 vertices to one with 4, calculate points along the 4-vertex curve at 1/10 intervals. Or come up with a better scheme.

6. Replace linear interpolation with splined interpolation to create smoother transitions between keyframes. Refer to section 21.1.3 in text for more info. Consider cubic B-splines (section 11.2.3).