/* Auteur: Nicolas JANEY              */
/* nicolas.janey@univ-fcomte.fr       */
/* Janvier 2004                       */
/* Un bras robot animable au clavier  */

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

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

static float r1 = 10.0F;
static float r2 = 20.0F;
static float r3 = 30.0F;
static float d = 0.2F;
static int lumiere = 0;
static int mode = 0;
static float size = 5.0F;
static GLfloat couleurBlanc[] = { 1.0F,1.0F,1.0F,1.0F };
static GLfloat couleurRouge[] = { 1.0F,0.0F,0.0F,1.0F };
static GLfloat couleurVert[] = { 0.0F,1.0F,0.0F,1.0F };
static GLfloat couleurBleu[] = { 0.0F,0.0F,1.0F,1.0F };
static GLfloat couleurNoir[] = { 0.0F,0.0F,0.0F,1.0F };
static GLfloat couleurJaune[] = { 1.0F,1.0F,0.0F,1.0F };

void init(void) {
  GLfloat mat_shininess[] = { 50.0F };
  GLfloat light0_position[] = { 1.0F,1.0F,1.0F,0.0F };
  GLfloat light1_position[] = { -1.0F,1.0F,1.0F,0.0F };
  GLfloat light2_position[] = { 1.0F,-1.0F,1.0F,0.0F };
  glMaterialfv(GL_FRONT,GL_SPECULAR,couleurBlanc);
  glMaterialfv(GL_FRONT,GL_SHININESS,mat_shininess);
  glLightfv(GL_LIGHT0,GL_DIFFUSE,couleurRouge);
  glLightfv(GL_LIGHT1,GL_DIFFUSE,couleurVert);
  glLightfv(GL_LIGHT2,GL_DIFFUSE,couleurBleu);
  glLightfv(GL_LIGHT0,GL_POSITION,light0_position);
  glLightfv(GL_LIGHT1,GL_POSITION,light1_position);
  glLightfv(GL_LIGHT2,GL_POSITION,light2_position);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  glEnable(GL_LIGHT2);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_NORMALIZE);
  glEnable(GL_AUTO_NORMAL);
  glClearColor(0.0F,0.0F,0.0F,1.0F);
}

void mandibule(float d) {
  glPushMatrix();
  glTranslatef(0.0F,0.0F,-d-0.2F) ;
  glColor3fv(couleurJaune) ;
  glPushMatrix();
  glScalef(1.0F,1.2F,0.4F) ;
  glutSolidCube(1.0) ;
  glPopMatrix();
  glPopMatrix();
}

void robot(float r1,float r2,float r3,float d) {
  glPushMatrix();
  glRotatef(r1,0.0F,1.0F,0.0F) ;
  glTranslatef(1.5F,0.0F,0.0F) ;
  glColor3fv(couleurRouge) ;
  glPushMatrix();
  glScalef(3.0F,1.0F,1.0F) ;
  glutSolidCube(1.0) ;
  glPopMatrix();
  glTranslatef(1.5F,0.0F,0.0F) ;
  glRotatef(r2,0.0F,1.0F,0.0F) ;
  glTranslatef(1.5F,0.0F,0.0F) ;
  glColor3fv(couleurVert) ;
  glPushMatrix();
  glScalef(3.0F,0.8F,0.8F) ;
  glutSolidCube(1.0) ;
  glPopMatrix();
  glTranslatef(1.8F,0.0F,0.0F) ;
  glRotatef(r3,1.0F,0.0F,0.0F) ;
  glColor3fv(couleurBleu) ;
  glPushMatrix();
  glScalef(0.6F,1.2F,1.8F) ;
  glutSolidCube(1.0) ;
  glPopMatrix();
  glTranslatef(0.8F,0.0F,0.0F) ;
  mandibule(d);
  glRotatef(180.0F,1.0F,0.0F,0.0F);
  mandibule(d);
  glPopMatrix();
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  if ( lumiere )
    glEnable(GL_LIGHTING);
    else
    glDisable(GL_LIGHTING);
  glPolygonMode(GL_FRONT_AND_BACK,(mode) ? GL_LINE : GL_FILL);
  glPushMatrix();
  glRotatef(45.0F,1.0F,1.0F,1.0F);
  robot(r1,r2,r3,d);
  glPopMatrix();
  glFlush();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("\nAttention erreur %d\n",error);
  glutSwapBuffers();
}

void key(unsigned char key,int x,int y) {
  switch ( key ) {
    case '1'    : r1 += 1.0F;
                  glutPostRedisplay();
                  break;
    case '4'    : r1 -= 1.0F;
                  glutPostRedisplay();
                  break;
    case '2'    : r2 += 1.0F;
                  if ( r2 > 90.0F )
                    r2 = 90.0F;
                  glutPostRedisplay();
                  break;
    case '5'    : r2 -= 1.0F;
                  if ( r2 < -90.0F )
                    r2 = -90.0F;
                  glutPostRedisplay();
                  break;
    case '3'    : r3 += 1.0F;
                  glutPostRedisplay();
                  break;
    case '6'    : r3 -= 1.0F;
                  glutPostRedisplay();
                  break;
    case '7'    : d += 0.02F;
                  if ( d > 0.4F )
                    d = 0.4F;
                  glutPostRedisplay();
                  break;
    case '8'    : d -= 0.02F;
                  if ( d < 0.0F )
                    d = 0.0F;
                  glutPostRedisplay();
                  break;
    case 32     : lumiere = !lumiere;
                  glutPostRedisplay();
                  break;
    case 0x0D   : mode = !mode;
                  glutPostRedisplay();
                  break;
    case 27     : exit(0);
                  break; }
}

void reshape(int w,int l) {
  glViewport(0,0,w,l);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  if ( w > l )
    glOrtho((float) -w/l*size,(float) w/l*size,
            -size,size,
            -2*size,2*size);
    else
    glOrtho(-size,size,
            (float) -l/w*size,(float) l/w*size,
            -2*size,2*size);
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Interface utilisateur en GLUt"); 
  init();
  glutReshapeFunc(reshape);
  glutKeyboardFunc(key);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}