Scanline Fill
The algorithm can be sped up by filling lines. Instead of pushing each potential future pixel coordinate on the stack, it inspects the neighbour lines (previous and next) to find adjacent segments that may be filled in a future pass; the coordinates (either the start or the end) of the line segment are pushed on the stack. In most cases this scanline algorithm is at least an order of magnitude faster than the per-pixel one.
Efficiency: each pixel is checked once.
Read more about this topic: Flood Fill
Famous quotes containing the word fill:
“Do not put off your work until tomorrow and the day after. For the sluggish worker does not fill his barn, nor the one who puts off his work; industry aids work, but the man who puts off work always wrestles with disaster.”
—Hesiod (c. 8th century B.C.)