/* Auteur: Nicolas JANEY                     */
/* nicolas.janey@univ-fcomte.fr              */
/* Septembre 2005                            */
/* Ajustement du volume de visualisation     */
/* pour qu'une distance de 1 dans le repere  */
/* de modelisation corresponde               */
/* a une distance de 1 pixel a l'ecran       */

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

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

static int lumiere = 0;
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 };

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 scene(void) {
  glPushMatrix();
  glPushMatrix();
  glTranslatef(10,10,0.0F);
  glutSolidSphere(10.0,60,60);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(290,290,0.0F);
  glutSolidSphere(10.0,60,60);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(10,290,0.0F);
  glutSolidSphere(10.0,60,60);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(290,10,0.0F);
  glutSolidSphere(10.0,60,60);
  glPopMatrix();
  glPushMatrix();
  glTranslatef(150,150,0.0F);
  glutSolidSphere(10.0,60,60);
  glPopMatrix();
  glPopMatrix();
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glEnable(GL_LIGHTING);
  glPushMatrix();
  scene();
  glPopMatrix();
  glFlush();
  int error = glGetError();
  if ( error != GL_NO_ERROR )
    printf("\nAttention erreur %d\n",error);
  glutSwapBuffers();
}

void reshape(int w,int l) {
  glViewport(0,0,w,l);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(0,w,l,0,-100.0F,100.0F);
  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("Exemple"); 
  init();
  glutReshapeFunc(reshape);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}