program pir;
uses graph,crt;

const
  piramid: array [0..14] of real =
  (180,100,100,150,140,100.
  230,140,100,120,170,100,
  200,170,100);
  lindex: array [0..15] of integer =
  (0,1,0,2,3,0,4,1,2,4,2,3,4,1,3)

var xt,yt,zt:real;
    xan,yan,zan:real;
    sx,sy,sx1,sy1,p,zoom:integer;
procedure draw(color:byte);
begin
     for p:=0 to 11 do begin
     sx:=round(zoom*piramid[lindex[p*2]*3])+160;
     sy:=round(zoom*piramid[lindex[p*2]*3+1])+100;
     sx1:=round(zoom*piramid[lindex[p*2+1]*3])+160;
     sy1:=round(zoom*piramid[lindex[p*2+1]*3+1])+100;
     setcolor(color);
     line(sx,sy,sx1,sy1);
    end;
end;
procedure calc;
begin
     for p:=0 to 7 do begin
	  yt:=piramid[p*3+1]*cos(xan)-piramid[p*3+2]*sin(xan);
     zt:=piramid[p*3+1]*cos(xan)+piramid[p*3+2]*sin(xan);
     piramid[p*3+1]:=yt;
     piramid[p*3+2]:=zt;
     xt:=piramid[p*3]*cos(yan)-piramid[p*3+2]*sin(yan);
     zt:=piramid[p*3]*cos(yan)+piramid[p*3+2]*sin(yan);
     piramid[p*3]:=xt;
     piramid[p*3+2]:=zt;
     xt:=piramid[p*3]*cos(zan)-piramid[p*3+1]*sin(zan);
     yt:=piramid[p*3]*cos(zan)+piramid[p*3+1]*sin(zan);
     piramid[p*3]:=xt;
     piramid[p*3+1]:=yt;
     end;
end;
var gd,gm:integer;
    t:char;
begin
     gd:=detect;
     initgraph(gd,gm,'');
     zan:=0.1;
     yan:=0.02;
     xan:=0.02;
     zoom:=30;
     repeat
           draw(15);
           delay(2000);
           draw(0);
           calc;
           if keypressed
           then begin
                 t:=readkey;
		 case t of
		 '+':zoom:=zoom+1;
		 '-':zoom:=zoom-1;
	       end;
	     end
	  until t=#13;
	  closegraph;
end.