progs/redbook/double.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  31  * Unpublished-- rights reserved under the copyright laws of the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  *  double.c
  40  *  This is a simple double buffered program.
  41  *  Pressing the left mouse button rotates the rectangle.
  42  *  Pressing the middle mouse button stops the rotation.
  43  */
  44 #include <GL/glut.h>
  45 #include <stdlib.h>
  46
  47 static GLfloat spin = 0.0;
  48
  49 void display(void)
  50 {
  51    glClear(GL_COLOR_BUFFER_BIT);
  52    glPushMatrix();
  53    glRotatef(spin, 0.0, 0.0, 1.0);
  54    glColor3f(1.0, 1.0, 1.0);
  55    glRectf(-25.0, -25.0, 25.0, 25.0);
  56    glPopMatrix();
  57
  58    glutSwapBuffers();
  59 }
  60
  61 void spinDisplay(void)
  62 {
  63    spin = spin + 2.0;
  64    if (spin > 360.0)
  65       spin = spin - 360.0;
  66    glutPostRedisplay();
  67 }
  68
  69 void init(void)
  70 {
  71    glClearColor (0.0, 0.0, 0.0, 0.0);
  72    glShadeModel (GL_FLAT);
  73 }
  74
  75 void reshape(int w, int h)
  76 {
  77    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
  78    glMatrixMode(GL_PROJECTION);
  79    glLoadIdentity();
  80    glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);
  81    glMatrixMode(GL_MODELVIEW);
  82    glLoadIdentity();
  83 }
  84
  85 /* ARGSUSED2 */
  86 void mouse(int button, int state, int x, int y)
  87 {
  88    switch (button) {
  89       case GLUT_LEFT_BUTTON:
  90          if (state == GLUT_DOWN)
  91             glutIdleFunc(spinDisplay);
  92          break;
  93       case GLUT_MIDDLE_BUTTON:
  94          if (state == GLUT_DOWN)
  95             glutIdleFunc(NULL);
  96          break;
  97       default:
  98          break;
  99    }
 100 }
 101
 102 static void
 103 key(unsigned char k, int x, int y)
 104 {
 105   switch (k) {
 106   case 27:  /* Escape */
 107     exit(0);
 108     break;
 109   default:
 110     return;
 111   }
 112   glutPostRedisplay();
 113 }
 114
 115 /*
 116  *  Request double buffer display mode.
 117  *  Register mouse input callback functions
 118  */
 119 int main(int argc, char** argv)
 120 {
 121    glutInit(&argc, argv);
 122    glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
 123    glutInitWindowSize (250, 250);
 124    glutInitWindowPosition (100, 100);
 125    glutCreateWindow (argv[0]);
 126    init ();
 127    glutDisplayFunc(display);
 128    glutReshapeFunc(reshape);
 129    glutMouseFunc(mouse);
 130    glutKeyboardFunc(key);
 131    glutMainLoop();
 132    return 0;   /* ANSI C requires main to return int. */
 133 }