double.c revision 32001f49 
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31 * Unpublished-- rights reserved under the copyright laws of the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 "glut_wrap.h"
45#include <stdlib.h>
46
47static GLfloat spin = 0.0;
48static GLdouble t0 = 0.;
49
50static void display(void)
51{
52   glClear(GL_COLOR_BUFFER_BIT);
53   glPushMatrix();
54   glRotatef(spin, 0.0, 0.0, 1.0);
55   glColor3f(1.0, 1.0, 1.0);
56   glRectf(-25.0, -25.0, 25.0, 25.0);
57   glPopMatrix();
58
59   glutSwapBuffers();
60}
61
62static GLdouble gettime(void)
63{
64    return (GLdouble)(glutGet(GLUT_ELAPSED_TIME)) / 1000.;
65}
66
67static void spinDisplay(void)
68{
69   GLdouble t, dt;
70   t = gettime();
71   dt = t - t0;
72   t0 = t;
73   spin = spin + 120.0*dt;
74   if (spin > 360.0)
75      spin = spin - 360.0;
76   glutPostRedisplay();
77}
78
79static void init(void)
80{
81   glClearColor (0.0, 0.0, 0.0, 0.0);
82   glShadeModel (GL_FLAT);
83}
84
85static void reshape(int w, int h)
86{
87   glViewport (0, 0, (GLsizei) w, (GLsizei) h);
88   glMatrixMode(GL_PROJECTION);
89   glLoadIdentity();
90   glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);
91   glMatrixMode(GL_MODELVIEW);
92   glLoadIdentity();
93}
94
95/* ARGSUSED2 */
96static void mouse(int button, int state, int x, int y)
97{
98   switch (button) {
99      case GLUT_LEFT_BUTTON:
100         if (state == GLUT_DOWN)
101         {
102            t0 = gettime();
103            glutIdleFunc(spinDisplay);
104         }
105         break;
106      case GLUT_MIDDLE_BUTTON:
107         if (state == GLUT_DOWN)
108            glutIdleFunc(NULL);
109         break;
110      default:
111         break;
112   }
113}
114
115static void
116key(unsigned char k, int x, int y)
117{
118  switch (k) {
119  case 27:  /* Escape */
120    exit(0);
121    break;
122  default:
123    return;
124  }
125  glutPostRedisplay();
126}
127
128/*
129 *  Request double buffer display mode.
130 *  Register mouse input callback functions
131 */
132int main(int argc, char** argv)
133{
134   glutInit(&argc, argv);
135   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);
136   glutInitWindowSize (250, 250);
137   glutInitWindowPosition (100, 100);
138   glutCreateWindow (argv[0]);
139   init ();
140   glutDisplayFunc(display);
141   glutReshapeFunc(reshape);
142   glutMouseFunc(mouse);
143   glutKeyboardFunc(key);
144   glutMainLoop();
145   return 0;   /* ANSI C requires main to return int. */
146}
147