/*
 * Copyright (c) 1993-1997, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 *
 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
 */

/*
 * smooth.c
 * This program demonstrates smooth shading.
 * A smooth shaded polygon is drawn in a 3-D projection.
 */

#include <GL/glut.h>
#include <stdlib.h>

void init(void) 
{
   glClearColor (0.0, 0.0, 0.0, 0.0);
   glShadeModel (GL_SMOOTH);
}

void triangle(void)
{
   glBegin (GL_TRIANGLES);
   glColor3f (1.0, 0.0, 0.0);
   glVertex3f (5.0, 5.0, 0.0);
   glColor3f (0.0, 1.0, 0.0);
   glVertex3f (25.0, 5.0, 0.0);
   glColor3f (0.0, 0.0, 1.0);
   glVertex3f (5.0, 25.0, 0.0);
   glEnd();
}

void display(void)
{
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity();
   gluPerspective(60.0, 1.0, 1.0, 100.0);

   glMatrixMode (GL_MODELVIEW);
   glLoadIdentity();
   gluLookAt (10.0, 10.0, 30.0, 10.0, 10.0, 0.0, 0.0, 1.0, 0.0);

   glClear (GL_COLOR_BUFFER_BIT);
   triangle ();
   glFlush ();
}

void reshape (int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
}

/* ARGSUSED1 */
void keyboard(unsigned char key, int x, int y)
{
   switch (key) {
      case 27:    /* escape key */
         exit(0);
         break;
   }
}

int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
   glutInitWindowSize (500, 500); 
   glutInitWindowPosition (100, 100);
   glutCreateWindow (argv[0]);
   init ();
   glutDisplayFunc(display); 
   glutReshapeFunc(reshape);
   glutKeyboardFunc (keyboard);
   glutMainLoop();
   return 0;
}