8
Active Edge Table Example
Example of an AET containing edges
{FA, EF, DE, CD} on scan line 8:
•3.1: (y = 8) Get edges from ET bucket y (none in this case, y = 8 has no entry)
•3.2: Remove from the AET any entries where ymax = y (none here)
•3.3: Draw scan line. To handle multiple edges, group in pairs:
{FA,EF}, {DE,CD}
•3.4: y = y+1 (y = 8+1 = 9)
•3.5: Update x for non-vertical edges, as in simple
line drawing.
(FvDFH
pages 92, 99)
Current X
Slope
Y val