Hi
In attachment is my proposition of mandelbrot program. It is about 5%
faster.
changed:
1. output result
2. condition of limit move inner to loop
Darek
{ The Computer Language Shootout
http://shootout.alioth.debian.org
contributed by Ales Katona
modified by Vincent Snijders
}
program mandelbrot;
{$FPUTYPE SSE2}{$I-}
var n, x, y, bits,bit: Longint;
Cx, Cy: double;
procedure CalculatePoint; nostackframe;
const
Limit: double =4.0;
zero: double = 0.0;
var
i: longint;
GC,
Zr, Zi, Ti, Tr: Double;
begin
Zr := zero; Zi := Zr;
Tr := Zr; Ti := Zi;
GC := Limit;
i := 50;
repeat
Zi := 2 * Zr * Zi + Cy;
Zr := Tr - Ti + Cx;
Tr := Zr * Zr;
Ti := Zi * Zi;
if (Tr + Ti) >= GC then begin
bits := bits xor bit;
exit;
end;
dec(i);
until (i=0);
end;
{$FPUTYPE X87}
var
ss : shortstring;
bb : byte absolute ss;
textbuf:array[0..8191] of char;
procedure writeSS;
begin
write(ss);
end;
procedure writech( const ch : char);inline;
begin
if length(ss)=250 then begin
writess;
bb:=1;
end else begin
inc(bb);
end;
ss[bb]:=ch;
end;
begin
Val(ParamStr(1), n);
settextbuf(output,textbuf,sizeof(textbuf));
writeln('P4');
writeln(n,' ',n);
ss:='';
for y := 0 to n-1 do
begin
Cy := y * 2 / n - 1;
bits := 255; bit := 128;
for x := 0 to n-1 do
begin
Cx := x * 2 / n - 1.5;
CalculatePoint;
if bit > 1 then
bit := bit shr 1
else
begin
writech(chr(bits));
bits := 255; bit := 128;
end;
end;
if bit < 128 then writech(chr(bits xor((bit shl 1)-1)));
end;
write(ss);
end.
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