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Rem
bbdoc: noddybox.algorithm
EndRem
Module noddybox.algorithm
ModuleInfo "Framework: Various algorithm routines"
ModuleInfo "Copyright: Public Domain"
ModuleInfo "Author: Ian Cowburn"
ModuleInfo "Version: $Revision$"
' $Id$
Strict
Import brl.math
Import brl.linkedlist
Rem
bbdoc: Used to return points from algorithms.
EndRem
Type TAlgoPoint
Rem
bbdoc: The X co-ordinate of the point
EndRem
Field x:Int
Rem
bbdoc: The Y co-ordinate of the point
EndRem
Field y:Int
Rem
bbdoc: Create a point.
returns: Newly created point.
about: @x and @y are initialised with the passed parameters.
EndRem
Function Create:TAlgoPoint(x:Int, y:Int)
Local o:TAlgoPoint=New TAlgoPoint
o.x=x
o.y=y
Return o
End Function
End Type
Rem
bbdoc: Implements a Bresenham style line.
returns: A list of points making up the line.
about: @px1, @py1, @px2 and @py2 are the end points of the line.
EndRem
Function DoLine:TList(p1x:Int, p1y:Int, p2x:Int, p2y:Int)
Local list:TList=CreateList()
Local f:Int
Local dx:Int
Local dy:Int
Local ix:Int
Local iy:Int
Local incrE:Int
Local incrNE:Int
Local d:Int
Local x:Int
Local y:Int
Local ymode:Int
dx=p2x-p1x
dy=p2y-p1y
ix=Sgn(dx)
iy=Sgn(dy)
dx=Abs(dx)
dy=Abs(dy)
If dy>dx
ymode=True
d=dx*2-dy
incrE=dx*2
incrNE=(dx-dy)*2
Else
ymode=False
d=dy*2-dx
incrE=dy*2
incrNE=(dy-dx)*2
EndIf
x=p1x
y=p1y
list.AddLast(TAlgoPoint.Create(x,y))
If ymode
While y<>p2y
If d<=0
d:+incrE
y:+iy
Else
d:+incrNE
y:+iy
x:+ix
EndIf
list.AddLast(TAlgoPoint.Create(x,y))
Wend
Else
While x<>p2x
If d<=0
d:+incrE
x:+ix
Else
d:+incrNE
y:+iy
x:+ix
EndIf
list.AddLast(TAlgoPoint.Create(x,y))
Wend
EndIf
Return list
End Function
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