/* Examen de TD n°1 2012-2023                   */
/*                                              */
/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Novembre 2012                                */

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

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

#include "Modules/ModuleAxes.h"

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

static int question = 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 };

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

static void init(void) {
  const GLfloat shininess[] = { 50.0 };
  glMaterialfv(GL_FRONT,GL_SPECULAR,blanc);
  glMaterialfv(GL_FRONT,GL_SHININESS,shininess);
  glLightfv(GL_LIGHT0,GL_DIFFUSE,rouge);
  glLightfv(GL_LIGHT1,GL_DIFFUSE,jaune);
  glLightfv(GL_LIGHT2,GL_DIFFUSE,bleu);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  glEnable(GL_LIGHT2);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
  glEnable(GL_AUTO_NORMAL);
}

//////////////////////////////////////////////////

/* Variables et constantes globales question 2  */

#ifndef M_PI
#define M_PI 3.14159
#endif

/* Question 2a                                  */

static void cercle(void) {
  int n = 10000;
  glPushMatrix();
  glBegin(GL_LINE_LOOP);
  for ( int i = 0 ; i < n ; i++ ) {
    double a = i*2.0*M_PI/n;
    float x = 10.0*cos(a);
    float y = 10.0*sin(a);
    glVertex2f(x,y); }
  glEnd();
  glPopMatrix();
}

/* Question 2b                                  */

static void enroulementToroidal(void) {
  int n = 10000;
  int m = 50;
  glPushMatrix();
  glBegin(GL_LINE_LOOP);
  for ( int i = 0 ; i < n ; i++ ) {
    double a1 = i*2.0*M_PI/n;
    float x = (10.0+sin(m*a1))*cos(a1);
    float y = (10.0+sin(m*a1))*sin(a1);
    float z = cos(m*a1);
    glVertex3f(x,y,z); }
  glEnd();
  glPopMatrix();
}

/* Scene question 3a                            */

static void sceneQuestion3a(void) {
  glPushMatrix();
  glutSolidTorus(0.3,10.0,18,72);
  glPushMatrix();
  glTranslatef(10.0F,0.0F,0.0F);
  glutSolidSphere(1.0,36,36);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(-10.0F,0.0F,0.0F);
  glutSolidSphere(1.0,36,36);
  glPopMatrix();
  glPopMatrix();
}

/* Variables et constantes globales question 3  */

static float r1 = 0.0F;
static float r2 = 180.0F;

/* Scene questions 3b et 3c                     */

static void sceneQuestion3bEt3c(void) {
  glPushMatrix();
  glutSolidTorus(0.3,10.0,18,72);
  glPushMatrix();
  glRotatef(r1,0.0F,0.0F,1.0F);
  glTranslatef(10.0F,0.0F,0.0F);
  glutSolidSphere(1.0,36,36);
  glPopMatrix();
  glPushMatrix();
  glRotatef(r2,0.0F,0.0F,1.0F);
  glTranslatef(10.0F,0.0F,0.0F);
  glutSolidSphere(1.0,36,36);
  glPopMatrix();
  glPopMatrix();
}

/* Question 3b                                  */
/* Fonction executee lorsqu'aucun evenement     */
/* n'est en file d'attente                      */

static void idle3b(void) {
  r1 += 1.0F;
  r2 += -3.0F;
  glutPostRedisplay();
}

/* Variables et constantes globales question 3  */

static float v1 = 1.0F;
static float v2 = -3.0F;

/* Question 3c                                  */
/* Fonction executee lorsqu'aucun evenement     */
/* n'est en file d'attente                      */

static void idle3c(void) {
  static const float deltaMin = acos(0.98)*180.0/3.14159;
  float delta = (r2+v2)-(r1+v1);
  if ( ( delta < deltaMin ) || ( delta > 360.0-deltaMin ) ) {
    float dt;
    if ( delta < deltaMin )
      dt = fabs((r2-r1-deltaMin)/(v1-v2));
      else
      dt = fabs((r1-r2+360.0F-deltaMin)/(v1-v2));
    r1 += (2.0F*v1*dt-v1);
    r2 += (2.0F*v2*dt-v2);
    v1 = -v1;
    v2 = -v2; }
    else {
    r1 += v1;
    r2 += v2; }
  glutPostRedisplay();
}

/* Question 4                                   */
/* Fonction executee lors d'un changement       */
/* de la taille de la fenetre OpenGL            */

static void reshape(int tx,int ty) {
  glViewport(0,0,tx,ty); 
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  if ( tx >= ty )
    glOrtho(-12.0*(double) tx/ty,12.0*(double) tx/ty,
            -12.0,12.0,
            -12.0,12.0);
    else
    glOrtho(-12.0,12.0,
            -12.0*(double) ty/tx,12.0*(double) ty/tx,
            -12.0,12.0);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

//////////////////////////////////////////////////

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

static void display(void) {
  glClearColor(0.75F,0.75F,0.75F,1.0F);
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  const GLfloat light0_position[] = { 0.0,0.0,0.0,1.0 };
  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);
  glLineWidth(2.0);
  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);
  dessinAxes();
  switch (question) {
    case 0 :
      cercle();
      break;
    case 1 :
      enroulementToroidal();
      break;
    case 2 :
      sceneQuestion3a();
      break;
    case 3 :
    case 4 :
      sceneQuestion3bEt3c();
      break; }
  glPopMatrix();
  glLineWidth(1.0);
  glFlush();
  glutSwapBuffers();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("Attention erreur %d\n",error);
}

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

static void special(int code,int x,int y) {
  switch ( code ) {
    case GLUT_KEY_UP :
      rx += 1.0F;
      glutPostRedisplay(); 
      break;
    case GLUT_KEY_DOWN :
      rx -= 1.0F;
      glutPostRedisplay(); 
      break;
    case GLUT_KEY_LEFT :
      ry += 1.0F;
      glutPostRedisplay(); 
      break;
    case GLUT_KEY_RIGHT :
      ry -= 1.0F;
      glutPostRedisplay(); 
      break;
    case GLUT_KEY_PAGE_UP :
      rz += 1.0F;
      glutPostRedisplay(); 
      break;
    case GLUT_KEY_PAGE_DOWN :
      rz -= 1.0F;
      glutPostRedisplay(); 
      break; }
}

/* 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 0x0D :
      question = (question+1)%5;
      switch (question) {
        case 0 :
        case 1 :
        case 2 :
          glutIdleFunc(NULL);
          break;
        case 3 :
          r1 = 0.0F;
          r2 = 180.0F;
          v1 = 1.0F;
          v2 = -3.0F;
          glutIdleFunc(idle3b);
          break;
        case 4 :
          r1 = 0.0F;
          r2 = 180.0F;
          v1 = 1.0F;
          v2 = -3.0F;
          glutIdleFunc(idle3c);
          break; }
      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(300,300);
  glutInitWindowPosition(50,50);
  glutCreateWindow("Examen de TD n°1 2012-2013");
  init();
  glutSpecialFunc(special);
  glutKeyboardFunc(keyboard);
  glutReshapeFunc(reshape);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}