/* Auteur: Nicolas JANEY                      */
/* nicolas.janey@univ-fcomte.fr               */
/* Fevrier 2003                               */
/* Animation d'un maillage de facettes        */

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

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

#include "ModuleMenus.h"
#include "ModuleReshape.h"
#include "ModuleManipulateur.h"
#include "ModuleCouleurs.h"

static int mode = 2;
static int disc = 80;
static float d = 0.0F;
static float larg = 20.0F;
static float factz = 4.0F;
static float fact = 2.0F;

struct coordonnee {
  float x;
  float y;
  float z; };

struct coordonnee **tb;
struct coordonnee **no;

struct coordonnee **allocationTableau(int n) {
  struct coordonnee **t =(struct coordonnee **)
                           calloc(n,sizeof(struct coordonnee *));
  for ( int i = 0 ; i < n ; i++ )
    t[i] =(struct coordonnee *) calloc(n,sizeof(struct coordonnee));
  return(t);
}

void liberationTableau(struct coordonnee **t,int n) {
  for ( int i = 0 ; i < n ; i++ )
    free(t[i]);
  free(t);
}

void calculTableau(struct coordonnee **t,int n) {
  for ( int i = 0 ; i < n ; i++ )
    for ( int j = 0 ; j < n ; j++ ) {
      t[i][j].x = (float) larg*i/(n-1)-larg/2.0F;
      t[i][j].y = (float) larg*j/(n-1)-larg/2.0F;
      double dist = fact*sqrt(t[i][j].x*t[i][j].x+t[i][j].y*t[i][j].y);
      t[i][j].z =(float) factz*sin(dist+d)/(1+dist); }
}

void norme(struct coordonnee *v) {
  double d = sqrt(v->x*v->x+v->y*v->y+v->z*v->z);
  v->x /= d;
  v->y /= d;
  v->z /= d;
}

void calculNormales(struct coordonnee **no,int n) {
  struct coordonnee v1;
  struct coordonnee v2;
  for ( int i = 0 ; i < n ; i++ )
    for ( int j = 0 ; j < n ; j++ ) {
      float x = (float) larg*i/(n-1)-larg/2.0F;
      float y = (float) larg*j/(n-1)-larg/2.0F;
      v1.x = 1.0F;
      v1.y = 0.0F;
      v2.x = 0.0F;
      v2.y = 1.0F;
      double dist = fact*sqrt(x*x+y*y);
      double cs = cos(d+dist);
      double sn = sin(d+dist);
      v1.z = fact*factz*x*(cs/dist-sn/dist/dist)/(1+dist);
      v2.z = fact*factz*y*(cs/dist-sn/dist/dist)/(1+dist);
      norme(&v1);
      norme(&v2);
      no[i][j].x = v1.y*v2.z - v2.y*v1.z;
      no[i][j].y = v1.z*v2.x - v2.z*v1.x;
      no[i][j].z = v1.x*v2.y - v2.x*v1.y; }
}

void afficheTableauPoints(struct coordonnee **t,struct coordonnee **no,int n) {
  glBegin(GL_POINTS);
  for ( int i = 0 ; i < n ; i++ )
    for ( int j = 0 ; j < n ; j++ ) {
      glNormal3f(no[i][j].x,no[i][j].y,no[i][j].z);
      glVertex3f(t[i][j].x,t[i][j].y,t[i][j].z); }
  glEnd();
}

void afficheTableauLignes(struct coordonnee **t,struct coordonnee **no,int n) {
  for ( int i = 0 ; i < n ; i++ ) {
    glBegin(GL_LINE_STRIP);
    for ( int j = 0 ; j < n ; j++ ) {
      glNormal3f(no[i][j].x,no[i][j].y,no[i][j].z);
      glVertex3f(t[i][j].x,t[i][j].y,t[i][j].z); }
    glEnd(); }
  for ( int j = 0 ; j < n ; j++ ) {
    glBegin(GL_LINE_STRIP);
    for ( int i = 0 ; i < n ; i++ ) {
      glNormal3f(no[i][j].x,no[i][j].y,no[i][j].z);
      glVertex3f(t[i][j].x,t[i][j].y,t[i][j].z); }
    glEnd(); }
/*  glBegin(GL_LINES);
  for ( i = 0 ; i < n ; i++ ) {
    for ( j = 0 ; j < n ; j++ ) {
      glNormal3f(no[i][j].x,no[i][j].y,no[i][j].z);
      glVertex3f(t[i][j].x,t[i][j].y,t[i][j].z);
      glVertex3f(t[i][j].x+no[i][j].x,t[i][j].y+no[i][j].y,t[i][j].z+no[i][j].z);} }
  glEnd();*/
}

void afficheTableauFaces(struct coordonnee **t,struct coordonnee **no,int n) {
  for ( int i = 0 ; i < n-1 ; i++ ) {
    glBegin(GL_QUAD_STRIP);
    for ( int j = 0 ; j < n ; j++ ) {
      glNormal3f(no[i][j].x,no[i][j].y,no[i][j].z);
      glVertex3f(t[i][j].x,t[i][j].y,t[i][j].z);
      glNormal3f(no[i+1][j].x,no[i+1][j].y,no[i+1][j].z);
      glVertex3f(t[i+1][j].x,t[i+1][j].y,t[i+1][j].z); }
    glEnd(); }
}

void myinit(void) {
  GLfloat shinines[] = { 50.0F };
  GLfloat l_pos[] = { 1.0F,1.0F,1.0F,0.0F };
  glClearColor(0.5F,0.5F,0.8F,1.0F) ;
  glMaterialfv(GL_FRONT,GL_DIFFUSE,couleurBlanc());
  glMaterialfv(GL_FRONT,GL_SPECULAR,couleurGrisFonce());
  glMaterialfv(GL_FRONT,GL_SHININESS,shinines);
  glLightfv(GL_LIGHT0,GL_POSITION,l_pos);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_AUTO_NORMAL);
  glEnable(GL_NORMALIZE);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  manipulateurSouris();
  manipulateurClavier();
  switch ( mode ) {
    case 0 : afficheTableauPoints(tb,no,disc);
             break;
    case 1 : afficheTableauLignes(tb,no,disc);
             break;
    case 2 : afficheTableauFaces(tb,no,disc);
             break; }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

void key(unsigned char key,int x,int y) {
  if ( keyManipulateur(key,x,y) )
    glutPostRedisplay();
    else
    switch ( key ) {
      case 43   : fact *= 1.1F;
                  glutPostRedisplay() ;
                  break ;
      case 45   : fact /= 1.1F;
                  glutPostRedisplay() ;
                  break ;
      case 'a'  : liberationTableau(tb,disc);
                  liberationTableau(no,disc);
                  disc++ ;
                  tb = allocationTableau(disc);
                  no = allocationTableau(disc);
                  calculTableau(tb,disc);
                  calculNormales(no,disc);
                  glutPostRedisplay() ;
                  break ;
      case 'A'  : liberationTableau(tb,disc);
                  liberationTableau(no,disc);
                  disc-- ;
                  if ( disc < 3 )
                    disc = 3;
                  tb = allocationTableau(disc);
                  no = allocationTableau(disc);
                  calculTableau(tb,disc);
                  calculNormales(no,disc);
                  glutPostRedisplay() ;
                  break ;
      case 'c'  : factz *= 1.1F;
                  glutPostRedisplay() ;
                  break ;
      case 'C'  : factz /= 1.1F;
                  glutPostRedisplay() ;
                  break ;
      case ' '  : mode = (mode+1)%3 ;
                  glutPostRedisplay() ;
                  break ; }
}

void idle(void) {
  d -=0.05;
  calculTableau(tb,disc);
  calculNormales(no,disc);
  glutPostRedisplay();
}

int main(int argc,char **argv) {
  tb = allocationTableau(disc);
  no = allocationTableau(disc);
  calculTableau(tb,disc);
  calculTableau(no,disc);
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(450,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Animation d'un maillage de facettes");
  myinit(); 
  creationMenuBasique();
  setParametresOrthoBasique(-10.0,10.0,-10.0,10.0,-500.0,500.0);
  setManipulateurDistance(1.0F);
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(key);
  glutIdleFunc(idle);
  glutSpecialFunc(specialBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}