/* Une facette illuminee                        */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Septembre 2010                               */

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

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

#include "CoordonneesHomogenes.h"
#include "Position3D.h"
#include "Direction3D.h"
#include "FacetteTriangulaire.h"
#include "LumierePonctuelle.h"
#include "Energie.h"
#include "Couleur.h"
#include "Rotation.h"

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

static int obj = 0;
static int lum = 0;
static float rx = 0.0F;
static float ry = 0.0F;
static float rz = 0.0F;
static int n = 4;
static Rotation *rt = new Rotation();

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

void init(void) {
  const GLfloat shininess[] = { 50.0 };
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
  glEnable(GL_AUTO_NORMAL);
}

/* Scene dessinee                               */

void facette(Position3D *p1,Position3D *p2,Position3D *p3) {
  FacetteTriangulaire *fct = new FacetteTriangulaire(p1,p2,p3);
  Couleur *kd;
  Couleur *kr;
  switch ( lum ) {
    case 0 :
      kd = new Couleur(1.0,0.2,0.2);
      kr = new Couleur(0.0,0.8,0.8);
      break;
    case 1 :
      kd = new Couleur(1.0,0.2,0.2);
      kr = new Couleur(0.0,0.0,0.0);
      break;
    case 2 :
      kd = new Couleur(0.0,0.0,0.0);
      kr = new Couleur(0.0,0.8,0.8);
      break; }
  Position3D *pos = new Position3D(4.2,0.3,0.5);
  Couleur *jaunatre = new Couleur(1.0,1.0,1.0);
  LumierePonctuelle *lp = new LumierePonctuelle(pos,10.0,jaunatre);
  Position3D *obs = new Position3D(0.0,0.0,20.0);
  Energie *e1 = new Energie();
  Energie *e2 = new Energie();
  Energie *e3 = new Energie();
  { Energie *ed1 = new Energie();
    ed1->calculDiffusion(p1,fct,kd,lp);
    Energie *er1 = new Energie();
    er1->calculReflexionSpeculaire(p1,fct,kr,lp,obs);
    e1->r = ed1->r+er1->r;
    e1->v = ed1->v+er1->v;
    e1->b = ed1->b+er1->b;
    delete(ed1);
    delete(er1); }
  { Energie *ed2 = new Energie();
    ed2->calculDiffusion(p2,fct,kd,lp);
    Energie *er2 = new Energie();
    er2->calculReflexionSpeculaire(p2,fct,kr,lp,obs);
    e2->r = ed2->r+er2->r;
    e2->v = ed2->v+er2->v;
    e2->b = ed2->b+er2->b;
    delete(ed2);
    delete(er2); }
  { Energie *ed3 = new Energie();
    ed3->calculDiffusion(p3,fct,kd,lp);
    Energie *er3 = new Energie();
    er3->calculReflexionSpeculaire(p3,fct,kr,lp,obs);
    e3->r = ed3->r+er3->r;
    e3->v = ed3->v+er3->v;
    e3->b = ed3->b+er3->b;
    delete(ed3);
    delete(er3); }
  glBegin(GL_TRIANGLES);
  glColor3dv((double *) e1);
  glVertex3dv((double *) p1);
  glColor3dv((double *) e2);
  glVertex3dv((double *) p2);
  glColor3dv((double *) e3);
  glVertex3dv((double *) p3);
  glEnd();
  delete(e1);
  delete(e2);
  delete(e3);
  delete(obs);
  delete(pos);
  delete(jaunatre);
  delete(lp);
  delete(kd);
  delete(kr);
  delete(fct);
}

void facetteSimple(void) {
  Position3D *p1 = new Position3D(3.0,-1.0,0.0);
  Position3D *p2 = new Position3D(-1.0,3.0,1.0);
  Position3D *p3 = new Position3D(-3.0,-3.0,-1.0);
  p1->transforme(rt);
  p2->transforme(rt);
  p3->transforme(rt);
  facette(p1,p2,p3);
  delete(p3);
  delete(p2);
  delete(p1);
}

void subdivisionRecursive(Position3D *p1,Position3D *p2,Position3D *p3,int n) {
  if ( n == 0 )
    facette(p1,p2,p3);
    else {
    Position3D *p12 = new Position3D((p1->c[0]+p2->c[0])/2.0,
                                     (p1->c[1]+p2->c[1])/2.0,
                                     (p1->c[2]+p2->c[2])/2.0);
    Position3D *p23 = new Position3D((p3->c[0]+p2->c[0])/2.0,
                                     (p3->c[1]+p2->c[1])/2.0,
                                     (p3->c[2]+p2->c[2])/2.0);
    Position3D *p31 = new Position3D((p3->c[0]+p1->c[0])/2.0,
                                     (p3->c[1]+p1->c[1])/2.0,
                                     (p3->c[2]+p1->c[2])/2.0);
    subdivisionRecursive(p1,p12,p31,n-1);
    subdivisionRecursive(p2,p23,p12,n-1);
    subdivisionRecursive(p3,p31,p23,n-1);
    subdivisionRecursive(p23,p31,p12,n-1);
    delete(p12);
    delete(p23);
    delete(p31); }
}

void facetteSubdivisee(void) {
  Position3D *p1 = new Position3D(3.0,-1.0,0.0);
  Position3D *p2 = new Position3D(-1.0,3.0,1.0);
  Position3D *p3 = new Position3D(-3.0,-3.0,-1.0);
  p1->transforme(rt);
  p2->transforme(rt);
  p3->transforme(rt);
  subdivisionRecursive(p1,p2,p3,n);
  delete(p1);
  delete(p2);
  delete(p3);
}

void scene() {
  Rotation *rtx = new Rotation(35.0*cos(rx),1.0,0.0,0.0);
  Rotation *rty = new Rotation(35.0*cos(ry),0.0,1.0,0.0);
  Rotation *rtz = new Rotation(rz,0.0,0.0,1.0);
  rt->produit(rtx,rty);
  rt->produit(rt,rtz);
  glPushMatrix();
  switch ( obj ) {
    case 0 :
      facetteSimple();
      break;
    case 1 :
      facetteSubdivisee();
      break; }
  glPopMatrix();
  delete(rtx);
  delete(rty);
  delete(rtz);
}

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

void display(void) {
  glClearColor(0.5F,0.5F,0.5F,1.0F);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  scene();
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Erreur OpenGL\n",error);
}

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

void idle(void) {
  rx += 0.00311F ;
  ry += 0.00634F ;
  rz += 0.17174F ;
  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() ;
  gluPerspective(25.0F,(float) x/y,15.0,35.0) ;
  glMatrixMode(GL_MODELVIEW) ;
  glLoadIdentity() ;
  gluLookAt(0.0,0.0,20.0,0.0,0.0,0.0,0.0,1.0,0.0);
}

/* Fonction executee lors de l'appui            */
/* d'une touche alphanumerique du clavier       */

void keyboard(unsigned char key,int x,int y) {
  switch (key) {
    case 43  :
      n++;
      glutPostRedisplay();
      break;
    case 45  :
      n--;
      if ( n == 0 )
        n = 1;
      glutPostRedisplay();
      break;
    case 'f' :
      { static int face = 1;
        face = !face;
        glPolygonMode(GL_FRONT_AND_BACK,( face ) ? GL_FILL : GL_LINE); }
      glutPostRedisplay();
      break;
    case 0x20 :
      obj = (obj+1)%2;
      glutPostRedisplay();
      break;
    case 'l' :
      lum = (lum+1)%3;
      glutPostRedisplay();
      break;
    case 0x0D :
      { static int anim = 1;
        anim = !anim;
        glutIdleFunc(( anim ) ? idle : NULL); }
      break;
    case 0x1B :
      exit(0);
      break; }
}

/* Fonction executee lors de l'appui            */
/* d'une touche de curseur ou d'une touche      */
/* page up ou page down                         */

void special(int key,int x,int y) {
  switch(key) {
    case GLUT_KEY_UP :
      rx++;
      glutPostRedisplay() ;
      break;
    case GLUT_KEY_DOWN :
      rx--;
      glutPostRedisplay() ;
      break;
    case GLUT_KEY_LEFT :
      ry++;
      glutPostRedisplay() ;
      break;
    case GLUT_KEY_RIGHT :
      ry--;
      glutPostRedisplay() ;
      break;
    case GLUT_KEY_PAGE_UP :
      rz++;
      glutPostRedisplay() ;
      break;
    case GLUT_KEY_PAGE_DOWN :
      rz--;
      glutPostRedisplay() ;
      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("Une facette illuminee"); 
  init();
  glutKeyboardFunc(keyboard);
  glutSpecialFunc(special);
  glutReshapeFunc(reshape);
  glutIdleFunc(idle);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}