FloodFill - best way?
BlitzPlus Forums/BlitzPlus Programming/FloodFill - best way?
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| Hy, I'm writing a Paint Program and I've to solve a very simple thing: the flood fill. But this isn't as easy as I thaught... I tried a recoursive function: 1. Get Pixelcolor. 2. if Color correct fill the pixel 3. if Color correct goto step 1 but with the pixel -left ,-above, -right, -below 4. end function It's a big time until the program reaches the Final End. There's the code:
Global FillOnR,FillOnG,FillOnB,image=LoadImage("compiling.bmp")
DrawImage image,0,0 : Text 100,4,"please wait" : Delay 100
Fill(30,30 ,255,140,140 ,0)
DrawImage image,0,0
Repeat
Until GetKey()
End
;*************************************************************************
Function Fill(X,Y,R,G,B,level)
;If Rand(0,1000)=1 Then DrawImage image,0,0:Delay 10 ;activate to see process
If level>10000 Then Return ;safety
If X<0 Or Y<0 Or X>ImageWidth(image)-1 Or Y>ImageHeight(image)-1 Then Return;outside of image
col=ReadPixel(X,Y,ImageBuffer(image))
TheB=(col And 255) : TheG=(col Shr 8) And 255 : TheR=(col Shr 16) And 255 ;get the RGBcolors of position XY
If level=0 Then FillOnR=TheR : FillOnG=TheG : FillOnB=TheB ;get the color on which we are painting
If TheR=R And TheG=G And TheB=B Then Return ;don't fill red on red etc
If TheR=FillOnR And TheG=FillOnG And TheB=FillOnB Then WritePixel(X,Y,R*256*256+G*256+B,ImageBuffer(image)) :Else Return ; actually fills the point in the image!
Fill(X+1,Y,R,G,B,level+1) ; try to fill right one
Fill(X-1,Y,R,G,B,level+1) ; try to fill left one
Fill(X,Y+1,R,G,B,level+1) ; try to fill below
Fill(X,Y-1,R,G,B,level+1) ; try to fill above
End Function
;*************************************************************************
The problems: -it is slow -sometimes it doesn't fill the whole thing because recoursive levels above 12000 cause Blitz to crash... I wonder how Microsoft Paint does this thing. I click and next moment a huge and complex floodfill is complete! So it looks like (with my little proggy):   |
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| There is one in the Code Archives: Fast Flood Fill (ProPixel Code) by Snarty |
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| Thank you very much, Fredborg!:-) I'll try this out. |
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