[pattyka]

Este codigo es el que tengo del algoritmo DDA:

Código Delphi [-]
procedure line(x1,y1,x2,y2:integer);
Var
   dx,dy,steps,i:integer;
  xIncrement,yIncrement,x,y:real;
Begin
  dx:=x2-x1;
  dy:=y2-y1;
  if abs (dx) > abs (dy) then
      steps:=abs(dx)
  else
      steps:=abs(dy);
   xIncrement:=dx/steps;
   yIncrement:=dy/steps;
   x:=x1;
   y:=y1;
   form1.PaintBox1.Canvas.Pixels[round(x), round(y)]:=4;
   for i:=1 to steps do
   begin
       x:=x+xIncrement;
       y:=y+yIncrement;
       form1.PaintBox1.Canvas.Pixels[round(x), round(y)]:=4;
   end;
   form1.PaintBox1.Canvas.Pixels[round(x), round(y)]:=4;
End;

Espero me puedas ayudar...