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From: cs122cv@ux1.cso.uiuc.edu
Newsgroups: comp.graphics
Subject: Re: References to Flood Fill Routines
Message-ID: <5300034@ux1.cso.uiuc.edu>
Date: 5 May 90 18:51:00 GMT
References: <145@avatar.UUCP>
Lines: 49
Nf-ID: #R:avatar.UUCP:145:ux1.cso.uiuc.edu:5300034:000:1467
Nf-From: ux1.cso.uiuc.edu!cs122cv    May  5 13:51:00 1990



Here is Fortran code for a non-recursive flood-fill...

c	Given array dimensions x and y, some array field(x,y),
c	arrays xstack() and ystack() (each dimensioned to some
c	sufficiently large number), and seed {start_x,start_y}...
c
c	Field should be all 0's except for the border of the area
c	to be filled, which should be -1.  Upon exit, the area within
c	the border will be filled with 1's.

	  stack_count=1
  	  xstack(stack_count)=start_x
	  ystack(stack_count)=start_y

	  do while (stack_count.gt.0)
	    xpixel=xstack(stack_count)
	    ypixel=ystack(stack_count)
	    stack_count=stack_count-1
	    rxpixel=real(xpixel)
	    rypixel=real(ypixel)

	    field(xpixel,ypixel)=1
	    if (field(xpixel+1,ypixel).eq.0) then
	        stack_count=stack_count+1
	        xstack(stack_count)=xpixel+1
	        ystack(stack_count)=ypixel
	    end if
	    if (field(xpixel-1,ypixel).eq.0) then
	        stack_count=stack_count+1
	        xstack(stack_count)=xpixel-1
	        ystack(stack_count)=ypixel
	    end if
	    if (field(xpixel,ypixel-1).eq.0) then
	        stack_count=stack_count+1
	        xstack(stack_count)=xpixel
	        ystack(stack_count)=ypixel-1
	    end if
	    if (field(xpixel,ypixel+1).eq.0) then
	        stack_count=stack_count+1
	        xstack(stack_count)=xpixel
	        ystack(stack_count)=ypixel+1
	    end if
	  end do

---Marc Andreessen
   Materials Research Lab, University of Illinois
   andreessen%uimrl.dnet@uimrl5.mrl.uiuc.edu