text: #ifndef RESHAPE
  #define RESHAPE
  
  #include "opengl.h"
  
  void reshape (int w, int h)
  {
     glViewport (0, 0, (GLsizei) w, (GLsizei) h); 
     glMatrixMode (GL_PROJECTION);
     glLoadIdentity ();
     
     glFrustum (-1.0,1.0,-1.0,1.0,1.0,150.0);
    
     glMatrixMode (GL_MODELVIEW);
  }
  
  #endif
  