/* * Copyright (c) 1993-1997, Silicon Graphics, Inc. * ALL RIGHTS RESERVED  * Permission to use, copy, modify, and distribute this software for  * any purpose and without fee is hereby granted, provided that the above * copyright notice appear in all copies and that both the copyright notice * and this permission notice appear in supporting documentation, and that  * the name of Silicon Graphics, Inc. not be used in advertising * or publicity pertaining to distribution of the software without specific, * written prior permission.  * * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE, * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT, * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE. *  * US Government Users Restricted Rights  * Use, duplication, or disclosure by the Government is subject to * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph * (c)(1)(ii) of the Rights in Technical Data and Computer Software * clause at DFARS 252.227-7013 and/or in similar or successor * clauses in the FAR or the DOD or NASA FAR Supplement. * Unpublished-- rights reserved under the copyright laws of the * United States.  Contractor/manufacturer is Silicon Graphics, * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311. * * OpenGL(R) is a registered trademark of Silicon Graphics, Inc. *//* *  double.c *  This is a simple double buffered program. *  Pressing the left mouse button rotates the rectangle. *  Pressing the middle mouse button stops the rotation. */#include <GL/glut.h>#include <stdlib.h>static GLfloat spin = 0.0;void display(void){   glClear(GL_COLOR_BUFFER_BIT);   glPushMatrix();   glRotatef(spin, 0.0, 0.0, 1.0);   glColor3f(1.0, 1.0, 1.0);   glRectf(-25.0, -25.0, 25.0, 25.0);   glPopMatrix();   glutSwapBuffers();}void spinDisplay(void){   spin = spin + 2.0;   if (spin > 360.0)      spin = spin - 360.0;   glutPostRedisplay();}void init(void) {   glClearColor (0.0, 0.0, 0.0, 0.0);   glShadeModel (GL_FLAT);}void reshape(int w, int h){   glViewport (0, 0, (GLsizei) w, (GLsizei) h);   glMatrixMode(GL_PROJECTION);   glLoadIdentity();   glOrtho(-50.0, 50.0, -50.0, 50.0, -1.0, 1.0);   glMatrixMode(GL_MODELVIEW);   glLoadIdentity();}void mouse(int button, int state, int x, int y) {   switch (button) {      case GLUT_LEFT_BUTTON:         if (state == GLUT_DOWN)            glutIdleFunc(spinDisplay);         break;      case GLUT_MIDDLE_BUTTON:      case GLUT_RIGHT_BUTTON:         if (state == GLUT_DOWN)            glutIdleFunc(NULL);         break;      default:         break;   }}   /*  *  Request double buffer display mode. *  Register mouse input callback functions */int main(int argc, char** argv){   glutInit(&argc, argv);   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB);   glutInitWindowSize (250, 250);    glutInitWindowPosition (100, 100);   glutCreateWindow (argv[0]);   init ();   glutDisplayFunc(display);    glutReshapeFunc(reshape);    glutMouseFunc(mouse);   glutMainLoop();   return 0;   /* ANSI C requires main to return int. */}