progs/redbook/plane.c

   1
   2 /* Copyright (c) Mark J. Kilgard, 1994. */
   3
   4 /*
   5  * (c) Copyright 1993, Silicon Graphics, Inc.
   6  * ALL RIGHTS RESERVED
   7  * Permission to use, copy, modify, and distribute this software for
   8  * any purpose and without fee is hereby granted, provided that the above
   9  * copyright notice appear in all copies and that both the copyright notice
  10  * and this permission notice appear in supporting documentation, and that
  11  * the name of Silicon Graphics, Inc. not be used in advertising
  12  * or publicity pertaining to distribution of the software without specific,
  13  * written prior permission.
  14  *
  15  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  16  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  18  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  19  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  20  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  21  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  22  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  23  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  24  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  25  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  26  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  27  *
  28  * US Government Users Restricted Rights
  29  * Use, duplication, or disclosure by the Government is subject to
  30  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  31  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  32  * clause at DFARS 252.227-7013 and/or in similar or successor
  33  * clauses in the FAR or the DOD or NASA FAR Supplement.
  34  * Unpublished-- rights reserved under the copyright laws of the
  35  * United States.  Contractor/manufacturer is Silicon Graphics,
  36  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  37  *
  38  * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
  39  */
  40 /*
  41  *  plane.c
  42  *  This program demonstrates the use of local versus
  43  *  infinite lighting on a flat plane.
  44  */
  45 #include <stdlib.h>
  46 #include <GL/glut.h>
  47
  48 /*  Initialize material property, light source, and lighting model.
  49  */
  50 void myinit(void)
  51 {
  52     GLfloat mat_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  53 /*   mat_specular and mat_shininess are NOT default values      */
  54     GLfloat mat_diffuse[] = { 0.4, 0.4, 0.4, 1.0 };
  55     GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  56     GLfloat mat_shininess[] = { 15.0 };
  57
  58     GLfloat light_ambient[] = { 0.0, 0.0, 0.0, 1.0 };
  59     GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
  60     GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
  61     GLfloat lmodel_ambient[] = { 0.2, 0.2, 0.2, 1.0 };
  62
  63     glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
  64     glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
  65     glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  66     glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  67     glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
  68     glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
  69     glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
  70     glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
  71
  72     glEnable(GL_LIGHTING);
  73     glEnable(GL_LIGHT0);
  74     glDepthFunc(GL_LESS);
  75     glEnable(GL_DEPTH_TEST);
  76 }
  77
  78 void drawPlane(void)
  79 {
  80     glBegin (GL_QUADS);
  81     glNormal3f (0.0, 0.0, 1.0);
  82     glVertex3f (-1.0, -1.0, 0.0);
  83     glVertex3f (0.0, -1.0, 0.0);
  84     glVertex3f (0.0, 0.0, 0.0);
  85     glVertex3f (-1.0, 0.0, 0.0);
  86
  87     glNormal3f (0.0, 0.0, 1.0);
  88     glVertex3f (0.0, -1.0, 0.0);
  89     glVertex3f (1.0, -1.0, 0.0);
  90     glVertex3f (1.0, 0.0, 0.0);
  91     glVertex3f (0.0, 0.0, 0.0);
  92
  93     glNormal3f (0.0, 0.0, 1.0);
  94     glVertex3f (0.0, 0.0, 0.0);
  95     glVertex3f (1.0, 0.0, 0.0);
  96     glVertex3f (1.0, 1.0, 0.0);
  97     glVertex3f (0.0, 1.0, 0.0);
  98
  99     glNormal3f (0.0, 0.0, 1.0);
 100     glVertex3f (0.0, 0.0, 0.0);
 101     glVertex3f (0.0, 1.0, 0.0);
 102     glVertex3f (-1.0, 1.0, 0.0);
 103     glVertex3f (-1.0, 0.0, 0.0);
 104     glEnd();
 105 }
 106
 107 void display (void)
 108 {
 109     GLfloat infinite_light[] = { 1.0, 1.0, 1.0, 0.0 };
 110     GLfloat local_light[] = { 1.0, 1.0, 1.0, 1.0 };
 111
 112     glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 113
 114     glPushMatrix ();
 115     glTranslatef (-1.5, 0.0, 0.0);
 116     glLightfv (GL_LIGHT0, GL_POSITION, infinite_light);
 117     drawPlane ();
 118     glPopMatrix ();
 119
 120     glPushMatrix ();
 121     glTranslatef (1.5, 0.0, 0.0);
 122     glLightfv (GL_LIGHT0, GL_POSITION, local_light);
 123     drawPlane ();
 124     glPopMatrix ();
 125     glFlush ();
 126 }
 127
 128 void myReshape(int w, int h)
 129 {
 130     glViewport (0, 0, w, h);
 131     glMatrixMode (GL_PROJECTION);
 132     glLoadIdentity ();
 133     if (w <= h)
 134         glOrtho (-1.5, 1.5, -1.5*(GLdouble)h/(GLdouble)w,
 135             1.5*(GLdouble)h/(GLdouble)w, -10.0, 10.0);
 136     else
 137         glOrtho (-1.5*(GLdouble)w/(GLdouble)h,
 138             1.5*(GLdouble)w/(GLdouble)h, -1.5, 1.5, -10.0, 10.0);
 139     glMatrixMode (GL_MODELVIEW);
 140 }
 141
 142 static void
 143 key(unsigned char k, int x, int y)
 144 {
 145   switch (k) {
 146   case 27:  /* Escape */
 147     exit(0);
 148     break;
 149   default:
 150     return;
 151   }
 152   glutPostRedisplay();
 153 }
 154
 155 /*  Main Loop
 156  *  Open window with initial window size, title bar,
 157  *  RGBA display mode, and handle input events.
 158  */
 159 int main(int argc, char** argv)
 160 {
 161     glutInit(&argc, argv);
 162     glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 163     glutInitWindowSize (500, 200);
 164     glutCreateWindow (argv[0]);
 165     myinit();
 166     glutReshapeFunc (myReshape);
 167     glutDisplayFunc(display);
 168     glutKeyboardFunc(key);
 169     glutMainLoop();
 170     return 0;             /* ANSI C requires main to return int. */
 171 }