zbuffer1.c Example C Language Program

/*
zbuffer1.c:

A zbuffer() demo program that draws two intersecting planes.

This program requires the z-buffer option.
*/

#include <gl/gl.h>
#include <gl/device.h>

main()
{
   Device dev;
   short val;
   initialize();
   while (TRUE)
   {
      if (qtest())
      {
         dev = qread(&val);
         if (dev == ESCKEY)
         {
            zbuffer(FALSE);
            gexit();
            exit(0);
         }

         else if (dev == REDRAW)
         {
            reshapeviewport();
            drawpolys();
         }

      }

   }

}

initialize()
{

   int gid;
   float xmax,ymax;   

   prefposition(XMAXSCREEN/4, XMAXSCREEN*3/4, YMAXSCREEN/4, 
       YMAXSCREEN*3/4);
   gid = winopen("zbuffer1");
   winset(gid);
   winconstraints();   
   perspective(900, 1.34, 1.01, 500.0);
   lookat(-150.0, 90.0, 250.0, 50.0, 50.0, 0.0, 0);   
   lsetdepth(0xC00000,0x3FFFFF);   
   qdevice(ESCKEY);
   qdevice(REDRAW);
   qenter(REDRAW,gid);   
   zbuffer(TRUE);
}

drawpolys()
{

   zclear();
   color(BLACK);
   clear();   
   color(YELLOW);
   pmv(0.0, 0.0, 100.0);
   pdr(100.0, 0.0, 100.0);
   pdr(100.0, 100.0, 100.0);
   pdr(0.0, 100.0, 100.0);
   pclos();   
   color(RED);
   pmv(0.0, 0.0, 50.0);
   pdr(100.0, 0.0, 50.0);
   pdr(100.0, 100.0, 200.0);
   pdr(0.0, 100.0, 200.0);
   pclos();

}

Related Information

The lookat subroutine, pclos subroutine, pdr subroutine, perspective subroutine, pmv subroutine, zbuffer subroutine, zclear subroutine.