FloodFill

[BubikolRamios]

Any way to know the size of area that will be filled ?

[RayoGlauco]

Because of the way the FloodFill algorithm works, I don't think it's possible to know in advance what area will be filled, except in particular cases, where you have more information than the algorithm requires. In fact, the algorithm only asks for the starting point and doesn't ask for any geometric information about the area to be examined.

[wp]

There is no way to measure the floodfill area without actually performing the floodfill. But during the floodfill you simply can count the pixels which are set. The attached project does this by means of a derived TLazIntfImage which overrides the inherited SetInternalColor method to increment the pixel counter. The image gets a copy of the bitmap to be floodfilled so that the measuring process can be running in a hidden way.