/* Lignes polygonales 3D lissees et non lissees */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Octobre 2012                                 */

/* Une molecule de benzene : C6H6               */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Septembre 2012                               */

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

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

#include "LignePolygonale3D.h"
#include "Position3D.h"

/* Variables et constantes globales             */

static const float blanc[] = { 1.0F,1.0F,1.0F,1.0F };
static const float gris[]  = { 0.7F,0.7F,0.7F,1.0F };
static float rx = 0.0F;
static float ry = 0.0F;
static float rz = 0.0F;
static int n = 100;
static int nb = 0;
static int aff = 1;

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

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

static void init(void) {
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
}

/* Scene dessinee                               */

static void scene(void) {
  LignePolygonale3D *lp = new LignePolygonale3D(10);
  lp->set(0,&Position3D(-6.0,-4.0, 1.0));
  lp->set(1,&Position3D(-4.5,-3.0,-1.0));
  lp->set(2,&Position3D(-2.0, 2.0,-2.0));
  lp->set(3,&Position3D(-0.5, 4.0, 1.0));
  lp->set(4,&Position3D( 1.5, 5.0, 2.0));
  lp->set(5,&Position3D( 4.0, 4.0, 3.0));
  lp->set(6,&Position3D( 3.0,-1.0, 1.0));
  lp->set(7,&Position3D( 2.0, 3.0,-1.0));
  lp->set(8,&Position3D(-1.0, 2.0,-2.0));
  lp->set(9,&Position3D(-3.5,-4.0, 0.0));
  glColor3f(1.0F,0.0F,1.0F);
  lp->drawOpenGL(1);
  switch (aff) {
    case 0 :
      { LignePolygonale3D *lpl = new LignePolygonale3D(n,&lp->t[nb],&lp->t[nb+1],
                                                         &lp->t[nb+2],&lp->t[nb+3],
                                                         (MatriceDeBase *) &NRUBS);
        glColor3f(1.0F,1.0F,0.0F);
        lpl->drawOpenGL(0);
        delete(lpl); }
      break;
    case 1 :
      { LignePolygonale3D *lpl = new LignePolygonale3D(n,lp,(MatriceDeBase *) &NRUBS);
        glColor3f(1.0F,1.0F,0.0F);
        lpl->drawOpenGL(0);
        delete(lpl); }
      break; }
  delete(lp);
}

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

static void display(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  const GLfloat light0_position[] = { 1.0,1.0,1.0,0.0 };
  const GLfloat light1_position[] = { -1.0,1.0,1.0,0.0 };
  const GLfloat light2_position[] = { 1.0,-1.0,1.0,0.0 };
  glLightfv(GL_LIGHT0,GL_POSITION,light0_position);
  glLightfv(GL_LIGHT1,GL_POSITION,light1_position);
  glLightfv(GL_LIGHT2,GL_POSITION,light2_position);
  glPolygonMode(GL_FRONT_AND_BACK,(aff) ? GL_FILL : GL_LINE);
  glPushMatrix();
  glRotatef(rx,1.0F,0.0F,0.0F);
  glRotatef(ry,0.0F,1.0F,0.0F);
  glRotatef(rz,0.0F,0.0F,1.0F);
  scene();
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Erreur OpenGL: %d\n",error);
}

/* Fonction executee lors d'un changement       */
/* de la taille de la fenetre OpenGL            */
/* -> Ajustement de la camera de visualisation  */

static void reshape(int x,int y) {
  glViewport(0,0,x,y); 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(30.0F,(float) x/y,1.0,50.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  gluLookAt(0.0,10.0,15.0,0.0,0.0,0.0,0.0,1.0,0.0);
}

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

static void keyboard(unsigned char key,int x,int y) {
  switch ( key ) {
    case 0x0D :
      nb = (nb+1)%7;
      glutPostRedisplay(); 
      break;
    case 0x20 :
      aff = (aff+1)%2;
      glutPostRedisplay(); 
      break;
    case 43 :
      n++;
      glutPostRedisplay(); 
      break;
    case 47 :
      n--;
      if ( n == 1 )
        n = 2;
      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(450,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Une courbe B-Spline"); 
  init();
  glutKeyboardFunc(keyboard);
  glutSpecialFunc(special);
  glutReshapeFunc(reshape);
  glutKeyboardFunc(keyboard);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}