/* Courbe de Bezier                             */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Novembre 2012                                */

#define ____CHECKMEM____

#ifdef ____CHECKMEM____
  #define _CRTDBG_MAP_ALLOC
  #ifdef _DEBUG
    #define _AFXDLL
    #include <afx.h>
  #endif
  #include <stdlib.h>
  #include <crtdbg.h>
  #else
  #include <stdlib.h>
  #endif

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

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

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

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

static int anim = 0;

static float rx = 0.0F;
static float ry = 0.0F;
static float rz = 0.0F;
static const float blanc[] = { 1.0F,1.0F,1.0F,1.0F };
static const float jaune[] = { 1.0F,1.0F,0.0F,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 };

static LignePolygonale3D *lp = NULL;
static int np = 50;
static int n = 21;

/* Generation d'un nombre aleatoire reel        */
/* compris entre -v et v                        */

double random(double v) {
  return((v*(rand()%20000)/10000.0)-v);
}

static void initLp(void) {
  if ( lp )
    delete(lp);
  lp = new LignePolygonale3D(n);
  for ( int i = 0 ; i < n ; i++ ) {
    double fct =(double) 20.0/(n-1);
    lp->t[i]->c[0] = 5.0*cos((double)i)+random(0.5);
    lp->t[i]->c[1] = 10.0-(i*fct)+random(fct),
    lp->t[i]->c[2] = 5.0*sin((double)i)+random(0.5); }
}

static void clean(void) {
  if ( lp ) {
    delete(lp);
    lp = NULL; }
}

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

static void initGL(void) {
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
}

/* Scene dessinee                               */

static void scene(void) {
  glPushMatrix();
  glLineWidth(2.0);
  glColor3fv(jaune);
  lp->draw();
  LignePolygonale3D *ll = new LignePolygonale3D(lp,np);
  glColor3fv(rouge);
  ll->draw();
  delete(ll);
  glLineWidth(1.0);
  glPopMatrix();
}

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

static void display(void) {
  glClearColor(0.5F,0.5F,0.5F,0.5F);
  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);
  glRotatef(rz,0.0F,0.0F,1.0F);
  scene();
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Attention erreur %d\n",error);
}

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

static void idle(void) {
  rx += 0.3355F;
  ry += 0.6117F;
  rz += 0.4174F;
  glutPostRedisplay();
}

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

static void reshape(int x,int y) {
  glViewport(0,0,x,y); 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  gluPerspective(30.0F,(float) x/y,30.0,70.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
  gluLookAt(0.0,0.0,50.0,0.0,0.0,0.0,0.0,1.0,0.0);
}

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

static void keyboard(unsigned char key,int x,int y) {
  switch (key) {
    case 'p' :
      n--;
      if ( n < 2 )
        n = 2;
      initLp();
      glutPostRedisplay();
      break;
    case 'P' :
      n++;
      initLp();
      glutPostRedisplay();
      break;
    case 'm' :
      initLp();
      glutPostRedisplay();
      break;
    case 0x0D :
      anim = !anim;
      glutIdleFunc(( anim ) ? idle : NULL);
      break;
    case 43 :
      np++;
      glutPostRedisplay();
      break;
    case 45 :
      np--;
      if ( np < 2 )
        np = 2;
      glutPostRedisplay();
      break;
    case 0x1B :
      clean();
      exit(0);
      break; }
}

/* Fonction principale                          */

int main(int argc,char **argv) {

  #ifdef ____CHECKMEM____
  _CrtSetDbgFlag ( _CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF );
  //_crtBreakAlloc = 431;
  #endif

  atexit(clean);

  initLp();

  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300);
  glutInitWindowPosition(50,50);
  glutCreateWindow("Une courbe de Bezier");
  initGL();
  glutKeyboardFunc(keyboard);
  glutReshapeFunc(reshape);
  glutDisplayFunc(display);
  glutMainLoop();
  clean();
  return(0);
}