void OpenGLInit(void);
 
static void Animate(void );
static void Key_r(void );
static void Key_s(void );
static void Key_up(void );
static void Key_down(void );
static void ResizeWindow(int w, int h);
 
#include <stdlib.h>
#include <stdio.h>
#include <GL/lut.h>
 
static GLenum spinMode = GL_TRUE;
static GLenum singleStep = GL_FALSE;
 
static float HourOfDay = 0.0;
static float DayOfYear = 0.0;
static float AnimateIncrement = 24.0; 
static void KeyPressFunc( unsigned char Key, int x, int y )
{
	switch ( Key ) {
	case 'R':
	case 'r':
		Key_r();
		break;
	case 's':
	case 'S':
		Key_s();
		break;
	case 27:
		exit(1);
	}
}
 
static void SpecialKeyFunc( int Key, int x, int y )
{
	switch ( Key ) {
	case GLUT_KEY_UP:		
		Key_up();
		break;
	case GLUT_KEY_DOWN:
		Key_down();
		break;
	}
}
 
 
static void Key_r(void)
{
	if ( singleStep ) {			
		singleStep = GL_FALSE;
		spinMode = GL_TRUE;		
	}
	else {
		spinMode = !spinMode;	
	}
}
 
static void Key_s(void)
{
	singleStep = GL_TRUE;
	spinMode = GL_TRUE;
}
 
static void Key_up(void)
{
    AnimateIncrement *= 2.0;			
}
 
static void Key_down(void)
{
    AnimateIncrement /= 2.0;			
 
}
static void Animate(void)
{
 
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
    if (spinMode) {
        HourOfDay += AnimateIncrement;
        DayOfYear += AnimateIncrement/24.0;
 
        HourOfDay = HourOfDay - ((int)(HourOfDay/24))*24;
        DayOfYear = DayOfYear - ((int)(DayOfYear/365))*365;
		}
 
    glLoadIdentity();
 
    glTranslatef ( 0.0, 0.0, -8.0 );
 
	glRotatef( 15.0, 1.0, 0.0, 0.0 );
 
	glColor3f( 1.0, 1.0, 0.0 );			
    glutWireSphere( 1.0, 15, 15 );
 
    glRotatef( 360.0*DayOfYear/365.0, 0.0, 1.0, 0.0 );
    glTranslatef( 4.0, 0.0, 0.0 );
    glPushMatrix();					
 
	glRotatef( 360.0*HourOfDay/24.0, 0.0, 1.0, 0.0 );
 
    glColor3f( 0.2, 0.2, 1.0 );
    glutWireSphere( 0.4, 10, 10);
    glPopMatrix();					
 
   	glRotatef( 360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 );
    glTranslatef( 0.7, 0.0, 0.0 );
    glColor3f( 0.3, 0.7, 0.3 );
    glutWireSphere( 0.1, 5, 5 );
 
    glFlush();
    glutSwapBuffers();
 
	if ( singleStep ) {
		spinMode = GL_FALSE;
	}
 
	glutPostRedisplay();	
 
}
 
void OpenGLInit(void)
{
    glShadeModel( GL_FLAT );
    glClearColor( 0.0, 0.0, 0.0, 0.0 );
    glClearDepth( 1.0 );
    glEnable( GL_DEPTH_TEST );
}
 
static void ResizeWindow(int w, int h)
{
    float aspectRatio;
	h = (h == 0) ? 1 : h;
	w = (w == 0) ? 1 : w;
	glViewport( 0, 0, w, h );
	aspectRatio = (float)w/(float)h;
 
    glMatrixMode( GL_PROJECTION );
    glLoadIdentity();
    gluPerspective( 60.0, aspectRatio, 1.0, 30.0 );
 
    glMatrixMode( GL_MODELVIEW );
}
 
 
int main( int argc, char** argv )
{
	glutInit(&argc,argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH );
 
    glutInitWindowPosition( 0, 0 );
    glutInitWindowSize( 600, 360 );
    glutCreateWindow( "Tata Surya" );
 
    OpenGLInit();
 
	glutKeyboardFunc( KeyPressFunc );
	glutSpecialFunc( SpecialKeyFunc );
 
    glutReshapeFunc( ResizeWindow );
 
    glutDisplayFunc( Animate );
 
	glutMainLoop(  );
 
    return(0);	
 
}

#include <GL/glut.h>

#include<GL/lut.h>

switch ( Key ) {
case 'R':
case 'r':
Key_r();
break;
case 's':
case 'S':
Key_s();
break;
case 27:
exit(1);
}