{ > Src.Mandel }

{ MANDELBROT SETS in Pascal }
program Mandel(input,output,points) ;

const Maxiter = 320 ;

type byte = 0..255 ;

var points : packed file of byte ;
    ptstep,blx,bly,scale : real ;
    i,j : integer ;

function colour(cx,cy:real) : integer ;
var x,y,x2,y2 : real ;
    n : integer ;
begin
n:=0 ; x:=0 ; y:=0 ;
REPEAT
  y2:=y*y ; x2:=x*x ; y:=2*x*y+cy ; x:=x2-y2+cx ; n:=n+1
UNTIL (n = Maxiter) OR (x2+y2 >= 4.0) ;
colour:=n
end ;

procedure  writebytes (x: integer) ;
begin
  write (points,x MOD 256, x DIV 256)
end ;

{ MAIN PROGRAM }
begin
 mode(0) ;
 rewrite (points,'ManPts') ;
{ write ('Bottom Left') ; readln (blx,bly) ; } blx := -1.02 ; bly := 0.28 ;
{ write ('Scale') ; readln (scale) ; } scale := 0.0375 ;
 settime (0) ;
 ptstep := scale/512 ;
{ MAIN LOOP }
FOR i:=0 TO 511 do
begin
 write(i) ;
 FOR j:=0 TO 256 do {TO 511 STEP 2}
 begin
  writebytes(colour(blx+i*ptstep,bly+(j+j)*ptstep))
 end
end ;
writeln('END ',time)
END.