/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Septembre 2007                               */
/* Une animation en OpenGL                      */

#include <stdio.h>

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

#include "ModuleCubes.h"

/* Variables et constantes globales             */
/* pour les angles et les couleurs utilises     */

static float rotation = 0.0F;
static int solution = 0;
static int disc = 30;
static float rayon = 2.0F;
static const float blanc[] = { 1.0F,1.0F,1.0F,1.0F };
static const float rouge[] = { 1.0F,0.0F,0.0F,1.0F };
static const float vert[] = { 0.0F,1.0F,0.0F,1.0F };
static const float bleu[] = { 0.0F,0.0F,1.0F,1.0F };

/* Variables globales de gestion                */
/* de l'interactivite clavier et souris         */

static int clic = 0;
static int mx;
static int my;
static float rx = 0.0F;
static float ry = 0.0F;

/* Fonction d'initialisation des parametres     */
/* OpenGL ne changeant pas au cours de la vie   */
/* du programme                                 */

void init(void) {
  const GLfloat mat_shininess[] = { 80.0 };
  const GLfloat light0_position[] = {  2.0, 2.0,2.0,1.0 };
  const GLfloat light1_position[] = { -2.0, 2.0,2.0,1.0 };
  const GLfloat light2_position[] = {  2.0,-2.0,2.0,1.0 };
  glMaterialfv(GL_FRONT,GL_SPECULAR,blanc);
  glMaterialfv(GL_FRONT,GL_SHININESS,mat_shininess);
  glLightfv(GL_LIGHT0,GL_DIFFUSE,rouge);
  glLightfv(GL_LIGHT1,GL_DIFFUSE,vert);
  glLightfv(GL_LIGHT2,GL_DIFFUSE,bleu);
  glLightfv(GL_LIGHT0,GL_POSITION,light0_position);
  glLightfv(GL_LIGHT1,GL_POSITION,light1_position);
  glLightfv(GL_LIGHT2,GL_POSITION,light2_position);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  glEnable(GL_LIGHT2);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
  glEnable(GL_AUTO_NORMAL);
}

/* Scene dessinee                               */

void scene(float rayon) {
  glPushMatrix();
  glRotatef(rotation,0.0F,0.0F,1.0F);
  glPushMatrix();
  glTranslatef(-rayon,0.0F,0.0F);
  glutSolidSphere(1.0,disc,disc);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(rayon,0.0F,0.0F);
  mySolidCube(2.0,disc);
  glPopMatrix();
  glPopMatrix();
}

/* Fonction executee lors d'un rafraichissement */
/* de la fenetre de dessin                      */

void display2(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glRotatef(rx,1.0F,0.0F,0.0F);
  glRotatef(ry,0.0F,1.0F,0.0F);
  scene(rayon);
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

/* Fonction executee lors d'un rafraichissement */
/* de la fenetre de dessin                      */

void display1(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glRotatef(rx,1.0F,0.0F,0.0F);
  glRotatef(ry,0.0F,1.0F,0.0F);
  scene(2.0F);
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

/* Fonction executee lors qu'aucun evenement    */
/* n'est en file d'attente                      */

void idle2(void) {
  rotation += 1.0F;
  rayon -= 0.0005F;
  if ( rayon < 1.0F )
    rayon = 1.0F;
  glutPostRedisplay();
}

/* Fonction executee lors qu'aucun evenement    */
/* n'est en file d'attente                      */

void idle1(void) {
  rotation += 1.0F;
  glutPostRedisplay();
}

/* Fonction executee lors d'un clic de souris   */
/* dans la fenetre                              */

void mouse(int bouton,int etat,int x,int y) {
  if ( bouton == GLUT_LEFT_BUTTON ) {
    if ( etat == GLUT_DOWN ) {
      clic = 1;
      mx = x;
      my = y; }
    if ( etat == GLUT_UP ) {
      clic = 0; } }
}

/* Fonction executee lors d'un deplacement      */
/* de la souris sur la fenetre                  */
/* avec un bouton appuye                        */

void motion(int x,int y) {
  if ( clic ) {
    ry += (x-mx);
    rx += (y-my);
    mx = x;
    my = y;
    glutPostRedisplay(); }
}

/* Fonction executee lors d'un changement       */
/* de la taille de la fenetre OpenGL            */

void reshape(int x,int y) {
  glViewport(0,0,x,y); 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(-4.0,4.0,(double) -4.0*y/x,(double) 4.0*y/x,-4.0,4.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

/* Fonction executee lors de la frappe          */
/* d'une touche alphanumerique du clavier       */

void key(unsigned char key,int x,int y) {
  switch ( key ) {
    case 43   : disc++;
                glutPostRedisplay();
                break;
    case 45   : disc--;
                if ( disc < 1 )
                  disc = 1;
                glutPostRedisplay();
                break;
    case 0x20 : rayon = 2.0;
                glutPostRedisplay();
                break;
    case 0x0D : solution = (solution+1)%2;
                glutDisplayFunc(( solution == 0 ) ? display1 : display2);
                glutIdleFunc(( solution == 0 ) ? idle1 : idle2);
                glutPostRedisplay();
                break;
    case 0x1B : exit(0);
                break; }
}

/* Fonction principale                          */

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Un cube et une sphere en orbite"); 
  init();
  glutReshapeFunc(reshape);
  glutKeyboardFunc(key);
  glutMotionFunc(motion);
  glutMouseFunc(mouse);
  glutIdleFunc(idle1);
  glutDisplayFunc(display1);
  glutMainLoop();
  return(0);
}