/* Auteur: Nicolas JANEY                     */
/* nicolas.janey@univ-fcomte.fr              */
/* Mars 2003                                 */
/* Materiel FRONT et BACK transparents       */
/* sur une facette situee devant une sphere  */

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

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

#include "ModuleCouleurs.h"
#include "ModuleManipulateur.h"
#include "ModuleMenus.h"
#include "ModuleReshape.h"

static int disc = 50;
static int ordre = 1;

typedef struct Position {
  float x ;
  float y ;
  float z ; } Position ;

void dessineFacette(Position *p1,Position *p2,Position *p4,int disc) {
  float dx1 = (p2->x-p1->x)/disc;
  float dy1 = (p2->y-p1->y)/disc;
  float dz1 = (p2->z-p1->z)/disc;
  float dx2 = (p4->x-p1->x)/disc;
  float dy2 = (p4->y-p1->y)/disc;
  float dz2 = (p4->z-p1->z)/disc;
  glNormal3f(0.0F,0.0F,1.0F);
  glBegin(GL_QUADS);
  for ( int i = 0 ; i < disc ; i++ )
    for ( int j = 0 ; j < disc ; j++ ) {
      Position pp1 = { p1->x+i*dx1+j*dx2,
                       p1->y+i*dy1+j*dy2,
                       p1->z+i*dz1+j*dz2};
      Position pp2 = { pp1.x+dx1,pp1.y+dy1,pp1.z+dz1 };
      Position pp3 = { pp1.x+dx1+dx2,pp1.y+dy1+dy2,pp1.z+dz1+dz2 };
      Position pp4 = { pp1.x+dx2,pp1.y+dy2,pp1.z+dz2 };
      glVertex3fv((float *) &pp1);
      glVertex3fv((float *) &pp2);
      glVertex3fv((float *) &pp3);
      glVertex3fv((float *) &pp4); }
  glEnd();
}

void facette(void) {
  glPushMatrix();
  Position p1 = { -8.0F,-6.0F,0.0F } ;
  Position p2 = { 4.0F,-5.0F,0.0F } ;
  Position p3 = { -3.0F,7.0F,0.0F } ;
  glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
  glMaterialfv(GL_FRONT,GL_SPECULAR,couleurVert(1.0F));
  glMaterialfv(GL_FRONT,GL_DIFFUSE,couleurBleu(1.0F));
  glMaterialfv(GL_BACK,GL_SPECULAR,couleurBlanc(0.5F));
  glMaterialfv(GL_BACK,GL_DIFFUSE,couleurRouge(0.5F));
  glMaterialf(GL_FRONT_AND_BACK,GL_SHININESS,64.0F);
  dessineFacette(&p1,&p2,&p3,disc);
  glPopMatrix();
}

void sphere(void) {
  glPushMatrix();
  glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_FALSE);
  glMaterialfv(GL_FRONT,GL_SPECULAR,couleurNoir(1.0F));
  glMaterialfv(GL_FRONT,GL_DIFFUSE,couleurBlanc(1.0F));
  glTranslatef(0.0F,0.0F,-10.0F);
  glutSolidSphere(2.0,72,72);
  glPopMatrix();
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  if ( ordre ) {
    sphere();
    manipulateurSouris();
    manipulateurClavier();
    facette(); }
    else {
    glPushMatrix();
    manipulateurSouris();
    manipulateurClavier();
    facette();
    glPopMatrix();
    sphere(); }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

void myinit (void) {
  glClearColor(0.5,0.5,0.5,1.0) ;
  GLfloat l_pos0[] = { 1.0,1.0,2.2,1.0 };
  glLightfv(GL_LIGHT0,GL_POSITION,l_pos0);
  GLfloat l_pos1[] = { -1.0,1.0,2.5,1.0 };
  glLightfv(GL_LIGHT1,GL_POSITION,l_pos1);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_LIGHT1);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glShadeModel(GL_SMOOTH);
}

void key(unsigned char key,int x,int y) {
  if ( keyManipulateur(key,x,y) )
    glutPostRedisplay();
    else
    switch ( key ) {
      case 0x0D  : ordre = !ordre;
                   glutPostRedisplay();
                   break;
      case 43    : disc++;
                   glutPostRedisplay();
                   break;
      case 45    : disc--;
                   if ( disc < 3 )
                     disc = 3;
                   glutPostRedisplay();
                   break; }
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300); 
  glutInitWindowPosition(50,50); 
  glutCreateWindow("Materiaux faces avant-arriere"); 
  myinit(); 
  creationMenuBasique();
  setParametresOrthoBasique(-10.0,10.0,-10.0,10.0,-50.0,50.0);
  setManipulateurDistance(1.0F);
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(key);
  glutSpecialFunc(specialBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutIdleFunc(idleBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}