progs/redbook/torus.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  31  * Unpublished-- rights reserved under the copyright laws of the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  *  torus.c
  40  *  This program demonstrates the creation of a display list.
  41  */
  42
  43 #include <GL/glut.h>
  44 #include <stdio.h>
  45 #include <math.h>
  46 #include <stdlib.h>
  47
  48 /* Some <math.h> files do not define M_PI... */
  49 #ifndef M_PI
  50 #define M_PI 3.14159265358979323846
  51 #endif
  52
  53 GLuint theTorus;
  54
  55 /* Draw a torus */
  56 static void torus(int numc, int numt)
  57 {
  58    int i, j, k;
  59    double s, t, x, y, z, twopi;
  60
  61    twopi = 2 * (double)M_PI;
  62    for (i = 0; i < numc; i++) {
  63       glBegin(GL_QUAD_STRIP);
  64       for (j = 0; j <= numt; j++) {
  65          for (k = 1; k >= 0; k--) {
  66             s = (i + k) % numc + 0.5;
  67             t = j % numt;
  68
  69             x = (1+.1*cos(s*twopi/numc))*cos(t*twopi/numt);
  70             y = (1+.1*cos(s*twopi/numc))*sin(t*twopi/numt);
  71             z = .1 * sin(s * twopi / numc);
  72             glVertex3f(x, y, z);
  73          }
  74       }
  75       glEnd();
  76    }
  77 }
  78
  79 /* Create display list with Torus and initialize state */
  80 static void init(void)
  81 {
  82    theTorus = glGenLists (1);
  83    glNewList(theTorus, GL_COMPILE);
  84    torus(8, 25);
  85    glEndList();
  86
  87    glShadeModel(GL_FLAT);
  88    glClearColor(0.0, 0.0, 0.0, 0.0);
  89 }
  90
  91 /* Clear window and draw torus */
  92 void display(void)
  93 {
  94    glClear(GL_COLOR_BUFFER_BIT);
  95    glColor3f (1.0, 1.0, 1.0);
  96    glCallList(theTorus);
  97    glFlush();
  98 }
  99
 100 /* Handle window resize */
 101 void reshape(int w, int h)
 102 {
 103    glViewport(0, 0, (GLsizei) w, (GLsizei) h);
 104    glMatrixMode(GL_PROJECTION);
 105    glLoadIdentity();
 106    gluPerspective(30, (GLfloat) w/(GLfloat) h, 1.0, 100.0);
 107    glMatrixMode(GL_MODELVIEW);
 108    glLoadIdentity();
 109    gluLookAt(0, 0, 10, 0, 0, 0, 0, 1, 0);
 110 }
 111
 112 /* Rotate about x-axis when "x" typed; rotate about y-axis
 113    when "y" typed; "i" returns torus to original view */
 114 /* ARGSUSED1 */
 115 void keyboard(unsigned char key, int x, int y)
 116 {
 117    switch (key) {
 118    case 'x':
 119    case 'X':
 120       glRotatef(30.,1.0,0.0,0.0);
 121       glutPostRedisplay();
 122       break;
 123    case 'y':
 124    case 'Y':
 125       glRotatef(30.,0.0,1.0,0.0);
 126       glutPostRedisplay();
 127       break;
 128    case 'i':
 129    case 'I':
 130       glLoadIdentity();
 131       gluLookAt(0, 0, 10, 0, 0, 0, 0, 1, 0);
 132       glutPostRedisplay();
 133       break;
 134    case 27:
 135       exit(0);
 136       break;
 137    }
 138 }
 139
 140 int main(int argc, char **argv)
 141 {
 142    glutInitWindowSize(200, 200);
 143    glutInit(&argc, argv);
 144    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
 145    glutCreateWindow(argv[0]);
 146    init();
 147    glutReshapeFunc(reshape);
 148    glutKeyboardFunc(keyboard);
 149    glutDisplayFunc(display);
 150    glutMainLoop();
 151    return 0;
 152 }