/*graficacion en 3d Perspectiva conica
  D              distancia del observador
  (x3d,y3d,z3d)  punto en 3d
  (x2d,y2d)      punto en 2d
   x2d=y3d*D/z3d
   y2d=x3d*D/z3d
  Fernando Galindo Soria 19/iv/98 Cd. de Mexico */
#include <graphics.h>
/*#include <math.h>*/
#include <conio.h>
/*#include <time.h>
#include <stdlib.h>
#include <stdio.h>
#include <dos.h>*/
float D=30,x2d,y2d,x2d1,y2d1;
float f3d[][3]={50,100,10, 200,100,10, 200,200,10, 50,200,10, 50,100,10,
		50,100,15, 200,100,15, 200,200,15, 50,200,15, 50,100,15,
		50,100,10, 200,100,10, 200,100,15, 200,200,15, 200,200,10,
		50,200,10, 50,200,15, 50,100,15, 50,100,10};
float f3d1[][3]={125,200,12,
		 125,150,12, 50,100,10, 125,150,12, 200,100,10,
		 125,150,12, 50,100,15, 125,150,12, 200,100,15};
void main()
{ int i;
  int gd=DETECT,gm;
  initgraph(&gd,&gm,"");
   for (i=0;i<18;i++)
    line(f3d[i][0]*D/(D-f3d[i][2]),f3d[i][1]*D/(D-f3d[i][2]),f3d[i+1][0]*D/(D-f3d[i+1][2]),f3d[i+1][1]*D/(D-f3d[i+1][2]));
   setcolor(2);
   for (i=0;i<8;i++)
    line(f3d1[i][0]*D/(D-f3d1[i][2]),f3d1[i][1]*D/(D-f3d1[i][2]),f3d1[i+1][0]*D/(D-f3d1[i+1][2]),f3d1[i+1][1]*D/(D-f3d1[i+1][2]));
   getch();
  closegraph();
}