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:
“Whatever we have got has been by infinite labour, and search, and ranging through every corner of nature; the difference is that instead of dirt and poison, we have rather chosen to fill our hives with honey and wax, thus furnishing mankind with the two noblest of things, which are sweetness and light.”
—Jonathan Swift (1667–1745)