/* Auteur: Nicolas JANEY                */
/* Avril 2001                           */
/* Progammation d'un systeme Terre-Lune */

#include <windows.h>

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glaux.h>

#include <stdio.h>
#include <stdlib.h>

static int year = 0, day = 0; 
  
void CALLBACK dayAdd(void) { 
  day = (day + 10) % 360; 
} 
  
void CALLBACK daySubtract(void) { 
  day = (day - 10) % 360; 
} 
  
void CALLBACK yearAdd(void) { 
  year = (year + 5) % 360; 
} 
  
void CALLBACK yearSubtract(void) { 
  year = (year - 5) % 360; 
} 
  
void CALLBACK display(void) { 
  glClear(GL_COLOR_BUFFER_BIT);
  glColor3f(0.0F,0.0F,0.0F);
  glPushMatrix(); 
  auxWireSphere(1.0); 
  glRotatef((GLfloat) year,0.0,1.0,0.0); 
  glTranslatef(2.0,0.0,0.0); 
  glRotatef((GLfloat) day,0.0,1.0,0.0); 
  auxWireSphere(0.2); 
  glPopMatrix(); 
  glFlush(); 
  auxSwapBuffers();
} 
  
void myinit(void) { 
  glClearColor(1.0,1.0,1.0,1.0);
} 
  
void CALLBACK myReshape(int w,int h) { 
  glViewport(0,0,w,h); 
  glMatrixMode(GL_PROJECTION); 
  glLoadIdentity(); 
  gluPerspective(36.0,(float) w/(float) h,1.0,20.0); 
  glMatrixMode(GL_MODELVIEW); 
  glLoadIdentity(); 
  glTranslatef(0.0,0.0,-5.0); 
} 
  
void main(void) { 
  auxInitDisplayMode(AUX_DOUBLE|AUX_RGB); 
  auxInitPosition(0,0,300,200); 
  auxInitWindow("Système Terre-Lune"); 
  myinit(); 
  auxKeyFunc(AUX_LEFT,yearSubtract); 
  auxKeyFunc(AUX_RIGHT,yearAdd); 
  auxKeyFunc(AUX_UP,dayAdd); 
  auxKeyFunc(AUX_DOWN,daySubtract); 
  auxReshapeFunc(myReshape); 
  auxMainLoop(display); 
}