Скачать Plasma Code

uses crt;
 
var
  i       : integer;
  licznik : byte;
  paleta  : array[0..767]of byte;
  screen  : array[0..63999]of byte absolute $A000:0;
 
{ This is necessaery for drawing plasma. Don't mind.
  It is the same piece of code I use in voxel space code posted here
  for several times, not necessarilly by me. }
 
function ncol(mc,n,dvd : integer): integer;
var
  loc : integer;
begin
  loc:=(mc+n-random(2*n)) div dvd;
  ncol:=loc;
  if loc>250 then ncol:=250;
  if loc<5 then ncol:=5
end;
 
procedure plasma(x1,y1,x2,y2 : word);
var
  xn,yn,dxy,p1,p2,p3,p4 : word;
begin
  if (x2-x1<2) and (y2-y1<2) then EXIT;
  p1:=screen[320*y1+x1];
  p2:=screen[320*y2+x1];
  p3:=screen[320*y1+x2];
  p4:=screen[320*y2+x2];
  xn:=(x2+x1) shr 1;
  yn:=(y2+y1) shr 1;
  dxy:=5*(x2-x1+y2-y1) div 3;
  if screen[320*y1+xn]=0 then screen[320*y1+xn]:=ncol(p1+p3,dxy,2);
  if screen[320*yn+x1]=0 then screen[320*yn+x1]:=ncol(p1+p2,dxy,2);
  if screen[320*yn+x2]=0 then screen[320*yn+x2]:=ncol(p3+p4,dxy,2);
  if screen[320*y2+xn]=0 then screen[320*y2+xn]:=ncol(p2+p4,dxy,2);
  screen[320*yn+xn]:=ncol(p1+p2+p3+p4,dxy,4);
  plasma(x1,y1,xn,yn);
  plasma(xn,y1,x2,yn);
  plasma(x1,yn,xn,y2);
  plasma(xn,yn,x2,y2)
end;
 
begin
  asm
    mov  ax,13h
    int  10h
  end;
{ Generating palette RGBs }
  for i:=1 to 170 do
    paleta[3*i]:=round(63*sin(i/170*pi));
  for i:=1 to 170 do
    paleta[3*i+256]:=round(63*sin(i/170*pi));
  for i:=1 to 170 do
    paleta[(3*i+512) mod 768]:=round(63*sin(i/170*pi));
  plasma(1,1,319,199);
{ Licznik - it means 'counter' in Polish.  }
  licznik:=0;
  repeat
{ Wait for retrace. }
    repeat until (port[$03DA] and 8)=0;
    repeat until (port[$03DA] and 8)=8;
{ Changing palette - we start with color number licznik }
    port[$3C8]:=licznik;
{ Three outsb are copying whole RGB to VGA register. After those three
  instructions value in port $3C8 is incremented.
  Here I'm redefining whole palette, but there is no problem in
  changing only one color. }
    asm
      mov  si,offset paleta
      mov  cx,768
      mov  dx,$3C9
      rep outsb
    end;
    inc(licznik);
  until keypressed;
  asm
    mov  ax,3h
    int  10h
  end;
end.