• cartesian
  rectangular grid
  
  CheckBoard
  
  Code for pf8bit color bitmap ( without mapping) is here :
  for iY:=0 to bitmap.Height-1 do
    begin
      Pointer := Bitmap.ScanLine[iY];
      if not Odd(trunc(iY div 10)) then bY:=true
        else bY:=false;
      for iX:=0 to bitmap.Width-1 do
        begin
          if Odd(trunc(iX div 10)) then bX:=true
            else bX:=false;
          if bX=bY then Pointer[iX]:=0 //white
            else Pointer[iX]:=19; //black
        end; // for iX
     end; // for iY
  
• polar
  
  • bad version
    Here You see fat lines due to round function.
    See the code:
    angle:=round(RadToDeg(pi+ArcTan2(iy-srodek.Y,srodek.X-ix)));
    if (angle mod 45 = 0) then Pointer[iX]:=16;
    
  • good version
  • 
    And here is improved version ( without edge detection):
    angle:=round(10*RadToDeg(pi+ArcTan2(iy-srodek.Y,srodek.X-ix)));
    if (angle mod (10*45) = 0) then Pointer[iX]:=16;
    
  • checkboard in polar coordinates
    

Feel free to e-mail me!

Author: Adam Majewski adammaj1-at-o2-dot-pl

http://republika.pl/fraktal/