SGI Developer Toolbox 6.1/SGI Developer Toolbox 6.1 - Disc 1.iso/toolbox/src/tutorials/custEducation/opengl1/examples/animation/menu.c

C/C++ Source or Header | 1996-11-11 | 4.6 KB | 205 lines

/*
 * Copyright 1996, Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This is UNPUBLISHED PROPRIETARY SOURCE CODE of Silicon Graphics, Inc.;
 * the contents of this file may not be disclosed to third parties, copied or
 * duplicated in any form, in whole or in part, without the prior written
 * permission of Silicon Graphics, Inc.
 *
 * RESTRICTED RIGHTS LEGEND:
 * Use, duplication or disclosure by the Government is subject to restrictions
 * as set forth in subdivision (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, DOD or NASA FAR Supplement. Unpublished -
 * rights reserved under the Copyright Laws of the United States.
 */

/*  menu.c - use popup menus to control animation of a robot arm
 *
 *  Right Mousebutton    - popup menu
 *  Escape key          - exit the program
 */
#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <math.h>    /* for fmodf */
#include <stdlib.h>    /* for NULL */
#include <stdio.h>    /* for printf */

/*  Function Prototypes  */

GLvoid  initgfx( GLvoid );
GLvoid  animate( GLvoid );
GLvoid  visibility( GLint );
GLvoid  drawScene( GLvoid );
GLvoid  reshape( GLsizei, GLsizei );
GLvoid  keyboard( GLubyte, GLint, GLint );
GLvoid  menu( GLint );

void printHelp( char * );

/*  Global Variables */

static GLfloat    shoulderAngle = 0.0;    /* controls shoulder rotation */

static GLboolean spinning = GL_TRUE;

/* Global Definitions */

#define KEY_ESC    27    /* ascii value for the escape key */

#define MENU_SPIN    1    /* animation control option */
#define MENU_EXIT    2    /* exit option */

void
main( int argc, char *argv[] )
{
    GLsizei width, height;

    glutInit( &argc, argv );

    width = glutGet( GLUT_SCREEN_WIDTH );
    height = glutGet( GLUT_SCREEN_HEIGHT );
    glutInitWindowPosition( 0, height / 4 );
    glutInitWindowSize( (width / 2) - 4, height / 2 );
    glutInitDisplayMode( GLUT_RGBA | GLUT_DEPTH | GLUT_DOUBLE );
    glutCreateWindow( argv[0] );

    initgfx();

    glutIdleFunc( animate );
    glutVisibilityFunc( visibility );
    glutKeyboardFunc( keyboard );
    glutReshapeFunc( reshape );
    glutDisplayFunc( drawScene );


    /* create menu and add menu options */
    glutCreateMenu( menu );
    glutAddMenuEntry( "Stop Rotating Arm", MENU_SPIN );
    glutAddMenuEntry( "Exit", MENU_EXIT );
    glutAttachMenu( GLUT_RIGHT_BUTTON );

    printHelp( argv[0] );

    glutMainLoop();
}

void
printHelp( char *progname )
{
    fprintf(stdout, "\n%s - smoothly animate a robot arm\n\n"
        "Axes: X - red, Y - green, Z - blue\n\n"
        "Right Mousebutton    - popup menu\n"
        "Escape Key        - exit the program\n",
        progname);
}

GLvoid
initgfx( GLvoid )
{
    glClearColor( 0.0, 0.0, 0.0, 1.0 );
    glShadeModel( GL_FLAT );
    glEnable( GL_DEPTH_TEST );
}

GLvoid
reshape( GLsizei width, GLsizei height )
{
    GLdouble    aspect;

    glViewport( 0, 0, width, height );

    aspect = (GLdouble) width / (GLdouble) height;

    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    gluPerspective( 45.0, aspect, 1.0, 20.0 );
    glMatrixMode( GL_MODELVIEW );
}

GLvoid
keyboard( GLubyte key, GLint x, GLint y )
{
    switch (key) {
    case KEY_ESC:    /* Exit when the Escape key is pressed */
        exit(0);
    }
}

GLvoid
animate( GLvoid )
{
    /* update the rotation of the shoulder for each scene */
    shoulderAngle = fmodf( (shoulderAngle + 1.0), 360.0 );

    glutPostRedisplay();    /* Tell GLUT to redraw the scene */
}

GLvoid
visibility( int state )
{
    /* restart the animation function if we were
     * animated when the window was hidden
     */
    if (state == GLUT_VISIBLE && spinning) {
        glutIdleFunc( animate );
    } else {
        glutIdleFunc( NULL );
    }
}

GLvoid
menu( int value )
{

    switch (value) {
    case MENU_SPIN:
        spinning = !spinning;
        if (spinning) {
            glutIdleFunc( animate );
            glutChangeToMenuEntry( MENU_SPIN, "Stop Rotating Arm",
                        MENU_SPIN );
        } else {
            glutIdleFunc( NULL );
            glutChangeToMenuEntry( MENU_SPIN, "Start Rotating Arm",
                        MENU_SPIN );
        }
        break;
    case MENU_EXIT:
        exit(0);
    }
}

GLvoid
drawScene( GLvoid )
{
    static GLfloat    upperArmColor[] = { 1.0, 0.0, 0.0 };
    static GLfloat    lowerArmColor[] = { 0.8, 0.5, 0.5 };

    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

    glPushMatrix();
        gluLookAt( 0.0, 0.0, 8.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0 );
        XYaxes();

        /* rotate the shoulder by shoulderAngle degrees */
        glRotatef( shoulderAngle, 0.0, 0.0, 1.0 );

        /* Draw the upper arm */
        glTranslatef( 1.0, 0.0, 0.0 );
            glColor3fv( upperArmColor );
        WireBox( 2.0, 0.4, 1.0 );

        /* Draw the lower arm */
        glTranslatef( 1.0, 0.0, 0.0 );
        glRotatef( 45.0, 0.0, 0.0, 1.0 );
        glTranslatef( 1.0, 0.0, 0.0 );
            glColor3fv( lowerArmColor );
        WireBox( 2.0, 0.4, 1.0 );
    glPopMatrix();

    glutSwapBuffers();
}