progs/redbook/bezmesh.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  34  * Unpublished-- rights reserved under the copyright laws of the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 /*  bezsurf.c
  41  *  This program renders a lighted, filled Bezier surface,
  42  *  using two-dimensional evaluators.
  43  */
  44 #include <stdlib.h>
  45 #include <GL/glut.h>
  46
  47 GLfloat ctrlpoints[4][4][3] =
  48 {
  49     {
  50         {-1.5, -1.5, 4.0},
  51         {-0.5, -1.5, 2.0},
  52         {0.5, -1.5, -1.0},
  53         {1.5, -1.5, 2.0}},
  54     {
  55         {-1.5, -0.5, 1.0},
  56         {-0.5, -0.5, 3.0},
  57         {0.5, -0.5, 0.0},
  58         {1.5, -0.5, -1.0}},
  59     {
  60         {-1.5, 0.5, 4.0},
  61         {-0.5, 0.5, 0.0},
  62         {0.5, 0.5, 3.0},
  63         {1.5, 0.5, 4.0}},
  64     {
  65         {-1.5, 1.5, -2.0},
  66         {-0.5, 1.5, -2.0},
  67         {0.5, 1.5, 0.0},
  68         {1.5, 1.5, -1.0}}
  69 };
  70
  71 void
  72 initlights(void)
  73 {
  74     GLfloat ambient[] =
  75     {0.2, 0.2, 0.2, 1.0};
  76     GLfloat position[] =
  77     {0.0, 0.0, 2.0, 1.0};
  78     GLfloat mat_diffuse[] =
  79     {0.6, 0.6, 0.6, 1.0};
  80     GLfloat mat_specular[] =
  81     {1.0, 1.0, 1.0, 1.0};
  82     GLfloat mat_shininess[] =
  83     {50.0};
  84
  85     glEnable(GL_LIGHTING);
  86     glEnable(GL_LIGHT0);
  87
  88     glLightfv(GL_LIGHT0, GL_AMBIENT, ambient);
  89     glLightfv(GL_LIGHT0, GL_POSITION, position);
  90
  91     glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
  92     glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
  93     glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
  94 }
  95
  96 void
  97 display(void)
  98 {
  99     glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 100     glPushMatrix();
 101     glRotatef(85.0, 1.0, 1.0, 1.0);
 102     glEvalMesh2(GL_FILL, 0, 20, 0, 20);
 103     glPopMatrix();
 104     glFlush();
 105 }
 106
 107 void
 108 myinit(void)
 109 {
 110     glClearColor(0.0, 0.0, 0.0, 1.0);
 111     glEnable(GL_DEPTH_TEST);
 112     glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4,
 113         0, 1, 12, 4, &ctrlpoints[0][0][0]);
 114     glEnable(GL_MAP2_VERTEX_3);
 115     glEnable(GL_AUTO_NORMAL);
 116     glEnable(GL_NORMALIZE);
 117     glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
 118     initlights();       /* for lighted version only */
 119 }
 120
 121 void
 122 myReshape(int w, int h)
 123 {
 124     glViewport(0, 0, w, h);
 125     glMatrixMode(GL_PROJECTION);
 126     glLoadIdentity();
 127     if (w <= h)
 128         glOrtho(-4.0, 4.0, -4.0 * (GLfloat) h / (GLfloat) w,
 129             4.0 * (GLfloat) h / (GLfloat) w, -4.0, 4.0);
 130     else
 131         glOrtho(-4.0 * (GLfloat) w / (GLfloat) h,
 132             4.0 * (GLfloat) w / (GLfloat) h, -4.0, 4.0, -4.0, 4.0);
 133     glMatrixMode(GL_MODELVIEW);
 134     glLoadIdentity();
 135 }
 136
 137 static void
 138 key(unsigned char k, int x, int y)
 139 {
 140   switch (k) {
 141   case 27:  /* Escape */
 142     exit(0);
 143     break;
 144   default:
 145     return;
 146   }
 147   glutPostRedisplay();
 148 }
 149
 150 int
 151 main(int argc, char **argv)
 152 {
 153     glutInit(&argc, argv);
 154     glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
 155     glutCreateWindow(argv[0]);
 156     myinit();
 157     glutReshapeFunc(myReshape);
 158     glutDisplayFunc(display);
 159     glutKeyboardFunc(key);
 160     glutMainLoop();
 161     return 0;             /* ANSI C requires main to return int. */
 162 }