/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Septembre 2007                               */
/* Un programme OpenGL                          */
/* de dessin de cubes et de cylindres           */
/* au moyen de primitives graphiques            */

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

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

#include "ModuleAxes.h"

#ifndef M_PI
#define M_PI 3.14159
#endif

/* Variables globales                           */

static int l = 1;
static int ff = 0;
static int sc = 0;
static int n = 18;

static float zoom = 1.0F;
static float px = 0.0F;
static float py = 0.0F;
static float pz = 0.0F;
static float rx = 0.0F;
static float ry = 0.0F;
static int clic = 0;
static int mx;
static int my;

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

void init(void) {
  const GLfloat l_pos[] = { 1.0F,1.0F,1.0F,0.0F };
  const GLfloat c[4] = { 0.5F,0.2F,0.6F,1.0F };
  glMaterialfv(GL_FRONT,GL_DIFFUSE,c);
  glLightfv(GL_LIGHT0,GL_POSITION,l_pos);
  glEnable(GL_LIGHT0);
  glColor4fv(c) ;
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
}

/* Dessin d'un cube sans specification          */
/* des normales                                 */

void mySolidCubeSansNormales(float c){
  c /= 2.0F;
  glPushMatrix();
  glBegin(GL_QUADS);
  { glVertex3f(c,c,-c);
    glVertex3f(c,-c,-c);
    glVertex3f(-c,-c,-c);
    glVertex3f(-c,c,-c); }
  { glVertex3f(c,c,c);
    glVertex3f(-c,c,c);
    glVertex3f(-c,-c,c);
    glVertex3f(c,-c,c); }
  { glVertex3f(-c,c,-c);
    glVertex3f(-c,-c,-c);
    glVertex3f(-c,-c,c);
    glVertex3f(-c,c,c); }
  { glVertex3f(c,c,c);
    glVertex3f(c,-c,c);
    glVertex3f(c,-c,-c);
    glVertex3f(c,c,-c); }
  { glVertex3f(-c,-c,c);
    glVertex3f(-c,-c,-c);
    glVertex3f(c,-c,-c);
    glVertex3f(c,-c,c); }
  { glVertex3f(c,c,c);
    glVertex3f(c,c,-c);
    glVertex3f(-c,c,-c);
    glVertex3f(-c,c,c); }
  glEnd();
  glPopMatrix();
}

/* Dessin d'un cube avec specification          */
/* des normales                                 */

void mySolidCubeAvecNormales(float c) {
  c /= 2.0F;
  glPushMatrix();
  glBegin(GL_QUADS);
  { glNormal3f(0.0F,0.0F,-1.0F);
    glVertex3f(c,c,-c);
    glVertex3f(c,-c,-c);
    glVertex3f(-c,-c,-c);
    glVertex3f(-c,c,-c); }
  { glNormal3f(0.0F,0.0F,1.0F);
    glVertex3f(c,c,c);
    glVertex3f(-c,c,c);
    glVertex3f(-c,-c,c);
    glVertex3f(c,-c,c); }
  { glNormal3f(-1.0F,0.0F,0.0F);
    glVertex3f(-c,c,-c);
    glVertex3f(-c,-c,-c);
    glVertex3f(-c,-c,c);
    glVertex3f(-c,c,c); }
  { glNormal3f(1.0F,0.0F,0.0F);
    glVertex3f(c,c,c);
    glVertex3f(c,-c,c);
    glVertex3f(c,-c,-c);
    glVertex3f(c,c,-c); }
  { glNormal3f(0.0F,-1.0F,0.0F);
    glVertex3f(-c,-c,c);
    glVertex3f(-c,-c,-c);
    glVertex3f(c,-c,-c);
    glVertex3f(c,-c,c); }
  { glNormal3f(0.0F,1.0F,0.0F);
    glVertex3f(c,c,c);
    glVertex3f(c,c,-c);
    glVertex3f(-c,c,-c);
    glVertex3f(-c,c,c); }
  glEnd();
  glPopMatrix();
}

/* Dessin d'un cylindre sans specification      */
/* des normales                                 */

void mySolidCylinderSansNormales(float r,float h,int n){
  float *cs =(float *) calloc(n,sizeof(float));
  float *sn =(float *) calloc(n,sizeof(float));
  int i;
  for( i = 0 ; i < n ; i++ ){
    float a = (2*M_PI*i)/n;
    sn[i] = sin(a);
    cs[i] = cos(a); }
  glPushMatrix();
  glBegin(GL_QUAD_STRIP);
  for( i = 0 ; i <= n ; i++ ){
    float x = r*cs[i%n];
    float z = -r*sn[i%n];
    glVertex3f(x,h/2,z);
    glVertex3f(x,-h/2,z); }
  glEnd();
  glBegin(GL_POLYGON);
  for( i = 0 ; i < n ; i++ ){
    float si = -sn[i];
    float ci = cs[i];
    glVertex3f(r*ci,h/2,r*si); }
  glEnd();
  glBegin(GL_POLYGON);
  for( i = 0 ; i < n ; i++ ){
    float si = sn[i];
    float ci = cs[i];
    glVertex3f(r*ci,-h/2,r*si); }
  glEnd();
  free(cs);
  free(sn);
  glPopMatrix();
}

/* Dessin d'un cylindre avec specification      */
/* des normales                                 */

void mySolidCylinderAvecNormales(float r,float h,int n){
  float *cs =(float *) calloc(n,sizeof(float));
  float *sn =(float *) calloc(n,sizeof(float));
  int i;
  for( i = 0 ; i < n ; i++ ){
    float a = (2*M_PI*i)/n;
    sn[i] = sin(a);
    cs[i] = cos(a); }
  glPushMatrix();
  glBegin(GL_QUAD_STRIP);
  for( i = 0 ; i <= n ; i++ ){
    float x = r*cs[i%n];
    float z = -r*sn[i%n];
    glNormal3f(cs[i%n],0.0F,-sn[i%n]);
    glVertex3f(x,h/2,z);
    glVertex3f(x,-h/2,z); }
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3f(0.0F,1.0F,0.0F);
  for( i = 0 ; i < n ; i++ ){
    float si = -sn[i];
    float ci = cs[i];
    glVertex3f(r*ci,h/2,r*si); }
  glEnd();
  glBegin(GL_POLYGON);
  glNormal3f(0.0F,-1.0F,0.0F);
  for( i = 0 ; i < n ; i++ ){
    float si = sn[i];
    float ci = cs[i];
    glVertex3f(r*ci,-h/2,r*si); }
  glEnd();
  free(cs);
  free(sn);
  glPopMatrix();
}

/* Scene dessinee                               */

void scene(void) {
  glPushMatrix();
  glPushMatrix();
  glTranslatef(1.0F,1.0F,0.0F);
  mySolidCubeAvecNormales(1.0F);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(-1.0F,-1.0F,0.0F);
  mySolidCubeSansNormales(1.0F);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(1.0F,-1.0F,0.0F);
  mySolidCylinderAvecNormales(0.5F,1.0F,n);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(-1.0F,1.0F,0.0F);
  mySolidCylinderSansNormales(0.5F,1.0F,n);
  glPopMatrix();
  glPopMatrix();
}

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

void display(void) {
  glClearColor(0.6F,0.6F,0.6F,1.0F) ;
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT) ;
  if ( l )
    glEnable(GL_LIGHTING);
    else
    glDisable(GL_LIGHTING);
  switch (ff) {
    case 0 : glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
             break;
    case 1 : glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
             break;
    case 2 : glPolygonMode(GL_FRONT,GL_LINE);
             glPolygonMode(GL_BACK,GL_FILL);
             break; }
  glPushMatrix();
  { glTranslatef(px,py,pz);
    glRotatef(rx,1.0F,0.0F,0.0F);
    glRotatef(ry,0.0F,1.0F,0.0F);
    glScalef(zoom,zoom,zoom); }
  glScalef(0.45F,0.45F,0.45F);
  axes();
  scene();
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Attention, erreur OpenGL %d\n",error);
}

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

void keyboard(unsigned char key,int x,int y) {
  switch ( key ) {
    case 'x'  : px -= zoom/50.0F;
                glutPostRedisplay();
                break;
    case 'X'  : px += zoom/50.0F;
                glutPostRedisplay();
                break;
    case 'y'  : py -= zoom/50.0F;
                glutPostRedisplay();
                break;
    case 'Y'  : py += zoom/50.0F;
                glutPostRedisplay();
                break;
    case 'z'  : pz -= 0.1F;
                glutPostRedisplay();
                break;
    case 'Z'  : pz += 0.1F;
                glutPostRedisplay();
                break;
    case 43   : n++;
                glutPostRedisplay();
                break;
    case 45   : n--;
                if ( n < 3 )
                  n = 3;
                glutPostRedisplay();
                break;
    case 's'  :
    case 'S'  : sc = (sc+1)%2 ;
                glutPostRedisplay();
                break;
    case 0x0D : l = !l ;
                glutPostRedisplay();
                break;
    case 0x20 : ff = (ff+1)%3 ;
                glutPostRedisplay();
                break;
    case 0x1B : exit(0); }
}

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

void special(int key,int x,int y) {
  switch ( key ) {
    case GLUT_KEY_PAGE_UP    : zoom *= 1.01F;
                               glutPostRedisplay();
                               break;
    case GLUT_KEY_PAGE_DOWN  : zoom /= 1.01F;
                               glutPostRedisplay();
                               break;
    case GLUT_KEY_UP         : rx -= 1.0F;
                               glutPostRedisplay();
                               break;
    case GLUT_KEY_DOWN       : rx += 1.0F;
                               glutPostRedisplay();
                               break;
    case GLUT_KEY_RIGHT      : ry += 1.0F;
                               glutPostRedisplay();
                               break;
    case GLUT_KEY_LEFT       : ry -= 1.0F;
                               glutPostRedisplay();
                               break; }
}

/* Fonction executee lors d'un clic de souris   */
/* dans la fenetre                              */

void mouse(int bouton,int etat,int x,int y) {
  if ( bouton == GLUT_LEFT_BUTTON ) {
    if ( etat == GLUT_DOWN ) {
      clic = 1;
      mx = x;
      my = y; }
    if ( etat == GLUT_UP ) {
      clic = 0; } }
}

/* Fonction executee lors d'un deplacement      */
/* de la souris sur la fenetre                  */
/* avec un bouton appuye                        */

void motion(int x,int y) {
  if ( clic ) {
    ry += (x-mx);
    rx += (y-my);
    mx = x;
    my = y;
    glutPostRedisplay(); }
}

/* Fonction executee lors d'un changement       */
/* de la taille de la fenetre OpenGL            */
/* Configuration d'une camera de visualisation  */
/* en projection orthographique                 */

void reshape(int tx,int ty) {
  glViewport(0,0,tx,ty);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho((double) -tx/ty,(double) tx/ty,-1.0,1.0,-5.0,5.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

/* Fonction principale                          */

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE|GLUT_DEPTH);
  glutInitWindowSize(350,350); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Cubes et cylindres");
  init(); 
  glutReshapeFunc(reshape);
  glutKeyboardFunc(keyboard);
  glutSpecialFunc(special);
  glutMouseFunc(mouse);
  glutMotionFunc(motion);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}