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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