/* Auteur: Nicolas JANEY                    */
/* nicolas.janey@univ-fcomte.fr             */
/* Mai 2002                                 */
/* Examen de TD 2000-2001 : Question 3      */
/* Modelisation d'une sphere avec facettes  */
/* normales et coordonnees de texturage     */

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

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

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

typedef float vecteur[3];
typedef float texture[2];

#define LI 64 
#define LH 64 

static int aff = 0;
static int obj = 0;
static int disc = 18;
static GLubyte image[LI][LH][3]; 
  
void makeImage(void) { 
  int i,j,c; 
  for( i = 0 ; i < LI ; i++ ) { 
    for( j = 0 ; j < LH ; j++ ) { 
      c =(((i&0x8)==0)^((j&0x8)==0))*255; 
      image[i][j][0] =(GLubyte) 255; 
      image[i][j][1] =(GLubyte) c; 
      image[i][j][2] =(GLubyte) c; } } 
} 
  
void myinit(void) {
  makeImage();
  glTexImage2D(GL_TEXTURE_2D,0,3,LI,LH,0,GL_RGB,GL_UNSIGNED_BYTE,&image[0][0][0]); 
  glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_S,GL_CLAMP); 
  glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_WRAP_T,GL_CLAMP); 
  glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST); 
  glTexParameterf(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST); 
  glClearColor(0.5F,0.5F,0.8F,1.0F) ;
  glEnable(GL_NORMALIZE);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHTING);
}

vecteur **coordonnees(int n,int m) {
  vecteur **p =(vecteur **) calloc(n,sizeof(vecteur *));
  int i;
  for ( i = 1 ; i <= n ;i++ ) {
    p[i-1] =(vecteur *) calloc(m,sizeof(vecteur));
    float a = -3.14159F/2.0F + i*3.14159/(n+1);
    float csa = cos(a);
    float sna = sin(a); 
    for ( int j = 0 ; j < m ;j++ ) {
      float b = j*3.14159F*2.0F/m;  
      float csb = cos(b);
      float snb = sin(b);
      p[i-1][j][0] = csb*csa;
      p[i-1][j][1] = snb*csa;
      p[i-1][j][2] = sna; } }
  return(p);
}

texture **textures(int n,int m) {
  texture **p =(texture **) calloc(n+2,sizeof(texture *));
  int i;
  for ( i = 0 ; i <= n+1 ; i++ ) {
    p[i] =(texture *) calloc(m+1,sizeof(texture));
    float a =(float) i/(n+1);
    for ( int j = 0 ; j <= m ;j++ ) {
      float b =(float) j/m;
      p[i][j][0] = a;
      p[i][j][1] = b; } }
  return(p);
}

void gouraudFacette3(vecteur p1,vecteur p2,vecteur p3,texture t1,texture t2,texture t3) {
  glTexCoord2fv(t1);
  glNormal3fv(p1);
  glVertex3fv(p1);
  glTexCoord2fv(t2);
  glNormal3fv(p2);
  glVertex3fv(p2);
  glTexCoord2fv(t3);
  glNormal3fv(p3);
  glVertex3fv(p3);
}

void gouraudFacette4(vecteur p1,vecteur p2,vecteur p3,vecteur p4,texture t1,texture t2,texture t3,texture t4) {
  glTexCoord2fv(t1);
  glNormal3fv(p1);
  glVertex3fv(p1);
  glTexCoord2fv(t2);
  glNormal3fv(p2);
  glVertex3fv(p2);
  glTexCoord2fv(t3);
  glNormal3fv(p3);
  glVertex3fv(p3);
  glTexCoord2fv(t4);
  glNormal3fv(p4);
  glVertex3fv(p4);
}

void sphere2(int n,int m) {
  vecteur sup = { 0.0F,0.0F,1.0F };
  vecteur inf = { 0.0F,0.0F,-1.0F };
  vecteur **p = coordonnees(n,m);
  texture **t = textures(n,m);
  int i;
  glBegin(GL_TRIANGLES);
  for ( i = 0 ; i < m ; i++ ) {
    gouraudFacette3(p[0][i],p[0][(i+1)%m],inf,t[1][i],t[1][i+1],t[0][i]); }
  for ( i = 0 ; i < m ; i++ ) {
    gouraudFacette3(p[n-1][i],p[n-1][(i+1)%m],sup,t[n][i],t[n][i+1],t[n+1][i]); }
  glEnd();
  glBegin(GL_QUADS);
  for ( int j = 0 ; j < n-1 ; j++ ) {
    for ( i = 0 ; i < m ; i++ ) {
      gouraudFacette4(p[j][i],p[j][(i+1)%m],p[j+1][(i+1)%m],p[j+1][i],t[j+1][i],t[j+1][i+1],t[j+2][i+1],t[j+2][i]); } }
  glEnd();
  for ( i = 0 ; i < n ; i++ ) 
    free(p[i]);
  free(p);
  for ( i = 0 ; i <= n+1 ; i++ ) 
    free(t[i]);
  free(t);
}

void vertex(float csa,float sna,float csb,float snb,float ts,float tt) {
  float x = csb*csa;
  float y = snb*csa;
  float z = sna;
  glTexCoord2f(ts,tt);
  glNormal3f(x,y,z);
  glVertex3f(x,y,z);
}

void sphere1(int n) {
  glBegin(GL_QUADS);
  for ( int i = 0 ; i < n ;i++ ) {
    float ta1 =(float) i/n;
    float ta2 =(float) (i+1)/n;
    float a1 = -3.14159F/2.0F + i*3.14159F/n;
    float csa1 = cos(a1);
    float sna1 = sin(a1); 
    float a2 = -3.14159F/2.0F + (i+1)*3.14159F/n;
    float csa2 = cos(a2);
    float sna2 = sin(a2); 
    for ( int j = 0 ; j < n ;j++ ) {
      float tb1 =(float) j/n; 
      float tb2 =(float) (j+1)/n; 
      float b1 = j*3.14159F*2.0F/n;  
      float csb1 = cos(b1);
      float snb1 = sin(b1);
      float b2 = (j+1)*3.14159F*2.0F/n;  
      float csb2 = cos(b2);
      float snb2 = sin(b2);
      vertex(csa1,sna1,csb1,snb1,ta1,tb1);
      vertex(csa1,sna1,csb2,snb2,ta1,tb2);
      vertex(csa2,sna2,csb2,snb2,ta2,tb2);
      vertex(csa2,sna2,csb1,snb1,ta2,tb1); } }
  glEnd();
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  manipulateurSouris();
  manipulateurClavier();
  switch ( aff ) {
    case 0 : glEnable(GL_TEXTURE_2D);  
             break;
    case 1 : glDisable(GL_TEXTURE_2D); 
             break; }
  switch ( obj ) {
    case 0 : sphere1(disc);
             break;
    case 1 : sphere2(disc,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   : disc++ ;
                  glutPostRedisplay() ;
                  break ;
      case 45   : disc-- ;
                  if ( disc < 3 )
                    disc = 3;
                  glutPostRedisplay() ;
                  break ;
      case ' '  : obj = (obj+1)%2 ;
                  glutPostRedisplay() ;
                  break ;
      case 0x0D : aff = (aff+1)%2 ;
                  glutPostRedisplay() ;
                  break ; }
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(200,200); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Modelisation sphere");
  myinit(); 
  creationMenuBasique();
  setParametresOrthoBasique(-1.5,1.5,-1.5,1.5,-50.0,50.0);
  setManipulateurDistance(1.0F);
  setManipulateurSourisAngle(20.0F,30.0F,40.0F);
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(key);
  glutSpecialFunc(specialBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}