{ MANDEL3.PAS                                                       }
{ Program vykresli mandelov obrazec.                                }
{                                                                   }
{                                                                   }
{ Datum:09.10.1994                             http://www.trsek.com }

uses crt;
var cc:char;

var X,Xbe,Y:longint;
    Yb,Ye,Xb,Xe:real;

var Z,Z1,C:
     record
       Re,Im:real;
     end;
    Krok:integer;


PROCEDURE Mandel;
begin
  C.Im:=Yb;
  while C.Im<=Ye do
  begin
    X:=Xbe;
    C.Re:=Xb;
    while C.Re<=Xe do
    begin
      Z.Re:=0;
      Z.Im:=0;
      Krok:=0;
      repeat
        Z1.Re:=Z.Re*Z.Re-Z.Im*Z.Im  +C.Re;        {Z[i+1]:=Z[i]*Z[i] + C}
        Z.Im:=2*Z.Re*Z.Im           +C.Im;

        Z.Re:=Z1.Re;

        inc(krok);
      until (krok>50) or (Abs(Z.Re*Z.Re+Z.Im*Z.Im)>4){ or (Abs(Z.Im)>2)};
      mem[$0a000:word(X+Y*320)]:=Krok mod 100;
      C.Re:=C.Re+(Xe-Xb)/320{round(200*1.203)};
      X:=X+1;
    end;
    C.Im:=C.Im+(Ye-Yb)/200;
    Y:=Y+1;
  end;
end;

begin
  asm
    mov ax,0013h
    int 10h
  end;

  Y:=0;     Xbe:=0;    Yb:=-1.5;  
  Ye:=1.5;  Xb:=-2.5;  Xe:=1.5;    
  Mandel;  
  cc:=readkey;

{
  Y:=0;     Xbe:=40;   Yb:=-0.5;
  Ye:=-0.4; Xb:=-0.35; Xe:=0.15;
  Mandel;
  cc:=readkey;
}

{
  Y:=0;     Xbe:=0;    Yb:=-0.457;
  Ye:=-0.449; Xb:=-0.156; Xe:=-0.147;
  Mandel;
  cc:=readkey;
}

end.