/* Auteur: Nicolas JANEY                        */
/* nicolas.janey@univ-fcomte.fr                 */
/* Septembre 2007                               */
/* Un programme OpenGL                          */
/* de dessin d'un bras robot                    */

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

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

#include "ModuleCylindres.h"

/* Variables globales pour l'activation         */
/* de la gestion des ombrages,                  */
/* du dessin en fil de fer,                     */
/* du dessin avec des cylindres                 */

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

/* 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'une "boite" parallelipipedique      */
/* en fil de fer                                */

void myWireCube(double w,double h,double d) {
  glPushMatrix();
  glScalef((float) w,(float) h,(float) d);
  glutWireCube(1.0);
  glPopMatrix();
}

/* Dessin d'une "boite" parallelipipedique      */

void mySolidCube(double w,double h,double d) {
  glPushMatrix();
  glScalef((float) w,(float) h,(float) d);
  glutSolidCube(1.0);
  glPopMatrix();
}

/* Dessin d'une "boite" parallelipipedique      */
/* en fil de fer ou non suivant la valeur       */
/* de la variable globale ff                    */

void myCube(double w,double h,double d) {
  glPushMatrix();
  if ( ff )
    myWireCube(w,h,d);
    else
    mySolidCube(w,h,d);
  glPopMatrix();
}

/* Dessin d'une sphere en fil de fer ou non     */
/* suivant la valeur de la variable globale ff  */

void mySphere(double r,int n1,int n2) {
  glPushMatrix();
  if ( ff )
    glutWireSphere(r,n1,n2);
    else
    glutSolidSphere(r,n1,n2);
  glPopMatrix();
}

/* Dessin d'un cylindre en fil de fer ou non    */
/* suivant la valeur de la variable globale ff  */

void myCylindre(double h,double d) {
  glPushMatrix();
  glRotatef(90.0F,0.0F,0.0F,1.0F);
  if ( ff )
    wireCylindre(d/2.0,h,18,10);
    else
    solidCylindre(d/2.0,h,18,10);
  glPopMatrix();
}

/* Une mandibule                                */

void mandibule(float d) {
  glPushMatrix();
  glTranslatef(0.0F,0.0F,-d-0.2F) ;
  myCube(1.0,1.2,0.4) ;
  glPopMatrix();
}

/* Le bras robot a base de cubes                */

void brasRobot01(float r1,float r2,float r3,float d) {
  glPushMatrix();
  glRotatef(r1,0.0F,1.0F,0.0F);
  glTranslatef(1.5F,0.0F,0.0F);
  myCube(3.0,1.0,1.0);
  glTranslatef(1.5F,0.0F,0.0F);
  glRotatef(r2,0.0F,1.0F,0.0F);
  glTranslatef(1.5F,0.0F,0.0F);
  myCube(3.0,0.8,0.8);
  glTranslatef(1.8F,0.0F,0.0F) ;
  glRotatef(r3,1.0F,0.0F,0.0F) ;
  myCube(0.6,1.2,1.8) ;
  glTranslatef(0.8F,0.0F,0.0F) ;
  mandibule(d);
  glRotatef(180.0F,1.0F,0.0F,0.0F);
  mandibule(d);
  glPopMatrix();
}

/* Le bras robot a base de cylindres            */

void brasRobot02(float r1,float r2,float r3,float d) {
  glPushMatrix();
  glRotatef(r1,0.0F,1.0F,0.0F);
  glTranslatef(1.5F,0.0F,0.0F);
  myCylindre(3.0,1.0);
  glTranslatef(1.5F,0.0F,0.0F);
  mySphere(0.7,18,18);
  glRotatef(r2,0.0F,1.0F,0.0F);
  glTranslatef(1.5F,0.0F,0.0F);
  myCylindre(3.0,0.8);
  glTranslatef(1.8F,0.0F,0.0F) ;
  glRotatef(r3,1.0F,0.0F,0.0F) ;
  myCube(0.6,1.2,1.8) ;
  glTranslatef(0.8F,0.0F,0.0F) ;
  mandibule(d);
  glRotatef(180.0F,1.0F,0.0F,0.0F);
  mandibule(d);
  glPopMatrix();
}

/* Scene dessinee                               */

void scene(void) {
  glPushMatrix();
  switch (sc) {
    case 0 : brasRobot01(30,-60,50,0.2);
             break;
    case 1 : brasRobot02(30,-60,50,0.2);
             break; }
  glPopMatrix();
}

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

void display(void) {
  glClearColor(0.8F,0.8F,0.8F,1.0F) ;
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT) ;
  if ( l )
    glEnable(GL_LIGHTING);
    else
    glDisable(GL_LIGHTING);
  glPushMatrix();
  glScalef(0.3F,0.3F,0.3F);
  glTranslatef(-4.0F,0.0F,0.0F);
  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 du clavier                      */

void keyboard(unsigned char key,int x,int y) {
  switch ( key ) {
    case 's'  :
    case 'S'  : sc = (sc+1)%2 ;
                glutPostRedisplay();
                break;
    case 0x0D : l = !l ;
                glutPostRedisplay();
                break;
    case 0x20 : ff = !ff ;
                glutPostRedisplay();
                break;
    case 0x1B : exit(0); }
}

/* 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,-1.0,1.0) ;
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

/* Fonction principale                          */

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DOUBLE|GLUT_DEPTH);
  glutInitWindowSize(500,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Bras robot");
  init(); 
  glutReshapeFunc(reshape);
  glutKeyboardFunc(keyboard);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}