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:
“Let no one think that I do not love the old ministers. They were, probably, the best men in their generation, and they deserve that their biographies should fill the pages of the town histories. If I could but hear the “glad tidings” of which they tell, and which, perchance, they heard, I might write in a worthier strain than this.”
—Henry David Thoreau (1817–1862)