progs/redbook/light.c

   1 /*
   2  * Copyright (c) 1993-1997, Silicon Graphics, Inc.
   3  * ALL RIGHTS RESERVED
   4  * Permission to use, copy, modify, and distribute this software for
   5  * any purpose and without fee is hereby granted, provided that the above
   6  * copyright notice appear in all copies and that both the copyright notice
   7  * and this permission notice appear in supporting documentation, and that
   8  * the name of Silicon Graphics, Inc. not be used in advertising
   9  * or publicity pertaining to distribution of the software without specific,
  10  * written prior permission.
  11  *
  12  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  13  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  14  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  15  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  16  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  17  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  18  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  19  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  20  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  21  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  22  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  23  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  24  *
  25  * US Government Users Restricted Rights
  26  * Use, duplication, or disclosure by the Government is subject to
  27  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  28  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  29  * clause at DFARS 252.227-7013 and/or in similar or successor
  30  * clauses in the FAR or the DOD or NASA FAR Supplement.
  31  * Unpublished-- rights reserved under the copyright laws of the
  32  * United States.  Contractor/manufacturer is Silicon Graphics,
  33  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  34  *
  35  * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
  36  */
  37
  38 /*
  39  *  light.c
  40  *  This program demonstrates the use of the OpenGL lighting
  41  *  model.  A sphere is drawn using a grey material characteristic.
  42  *  A single light source illuminates the object.
  43  */
  44 #include <GL/glut.h>
  45 #include <stdlib.h>
  46
  47 /*  Initialize material property, light source, lighting model,
  48  *  and depth buffer.
  49  */
  50 static void init(void)
  51 {
  52    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  53    GLfloat mat_shininess[] = { 50.0 };
  54    GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };
  55
  56    glClearColor (0.0, 0.0, 0.0, 0.0);
  57    glShadeModel (GL_SMOOTH);
  58
  59    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  60    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  61    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
  62
  63    glEnable(GL_LIGHTING);
  64    glEnable(GL_LIGHT0);
  65    glEnable(GL_DEPTH_TEST);
  66 }
  67
  68 static void display(void)
  69 {
  70    glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  71    glutSolidSphere (1.0, 20, 16);
  72    glFlush ();
  73 }
  74
  75 static void reshape (int w, int h)
  76 {
  77    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
  78    glMatrixMode (GL_PROJECTION);
  79    glLoadIdentity();
  80    if (w <= h)
  81       glOrtho (-1.5, 1.5, -1.5*(GLfloat)h/(GLfloat)w,
  82          1.5*(GLfloat)h/(GLfloat)w, -10.0, 10.0);
  83    else
  84       glOrtho (-1.5*(GLfloat)w/(GLfloat)h,
  85          1.5*(GLfloat)w/(GLfloat)h, -1.5, 1.5, -10.0, 10.0);
  86    glMatrixMode(GL_MODELVIEW);
  87    glLoadIdentity();
  88 }
  89
  90 /* ARGSUSED1 */
  91 static void keyboard(unsigned char key, int x, int y)
  92 {
  93    switch (key) {
  94       case 27:
  95          exit(0);
  96          break;
  97    }
  98 }
  99
 100 int main(int argc, char** argv)
 101 {
 102    glutInit(&argc, argv);
 103    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 104    glutInitWindowSize (500, 500);
 105    glutInitWindowPosition (100, 100);
 106    glutCreateWindow (argv[0]);
 107    init ();
 108    glutDisplayFunc(display);
 109    glutReshapeFunc(reshape);
 110    glutKeyboardFunc(keyboard);
 111    glutMainLoop();
 112    return 0;
 113 }