scene.c

OpenGL学习资料

/*
 * Copyright (c) 1993-1999, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 * Permission to use, copy, modify, and distribute this software for 
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that 
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission. 
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 * US Government Users Restricted Rights 
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
 */

/*
 *  scene.c
 *  This program demonstrates the use of the GL lighting model.
 *  Objects are drawn using a grey material characteristic. 
 *  A single light source illuminates the objects.
 */
#include <GL/glut.h>
#include <stdlib.h>

/*  Initialize material property and light source.
 */
void init (void)
{
   GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
   GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
   GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
/*	light_position is NOT default value	*/
   GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };

   glLightfv (GL_LIGHT0, GL_AMBIENT, light_ambient);
   glLightfv (GL_LIGHT0, GL_DIFFUSE, light_diffuse);
   glLightfv (GL_LIGHT0, GL_SPECULAR, light_specular);
   glLightfv (GL_LIGHT0, GL_POSITION, light_position);
   
   glEnable (GL_LIGHTING);
   glEnable (GL_LIGHT0);
   glEnable(GL_DEPTH_TEST);
}

void display (void)
{
   glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   glPushMatrix ();
   glRotatef (20.0, 1.0, 0.0, 0.0);

   glPushMatrix ();
   glTranslatef (-0.75, 0.5, 0.0); 
   glRotatef (90.0, 1.0, 0.0, 0.0);
   glutSolidTorus (0.275, 0.85, 15, 15);
   glPopMatrix ();

   glPushMatrix ();
   glTranslatef (-0.75, -0.5, 0.0); 
   glRotatef (270.0, 1.0, 0.0, 0.0);
   glutSolidCone (1.0, 2.0, 15, 15);
   glPopMatrix ();

   glPushMatrix ();
   glTranslatef (0.75, 0.0, -1.0); 
   glutSolidSphere (1.0, 15, 15);
   glPopMatrix ();

   glPopMatrix ();
   glFlush ();
}

void reshape(int w, int h)
{
   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
   glMatrixMode (GL_PROJECTION);
   glLoadIdentity ();
   if (w <= h) 
      glOrtho (-2.5, 2.5, -2.5*(GLfloat)h/(GLfloat)w, 
               2.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
   else 
      glOrtho (-2.5*(GLfloat)w/(GLfloat)h, 
               2.5*(GLfloat)w/(GLfloat)h, -2.5, 2.5, -10.0, 10.0);
   glMatrixMode (GL_MODELVIEW);
   glLoadIdentity ();
}

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

/*  Main Loop
 *  Open window with initial window size, title bar, 
 *  RGBA display mode, and handle input events.
 */
int main(int argc, char** argv)
{
   glutInit(&argc, argv);
   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
   glutInitWindowSize (500, 500);
   glutCreateWindow (argv[0]);
   init ();
   glutReshapeFunc (reshape);
   glutDisplayFunc(display);
   glutKeyboardFunc (keyboard);
   glutMainLoop();
   return 0; 
}