/* Auteur: Nicolas JANEY          */
/* nicolas.janey@univ-fcomte.fr   */
/* Juin 2001                      */
/* Facteur de forme en radiosite  */

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

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

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

struct coord3D {
  float x;
  float y;
  float z; } ;

struct direc3D {
  float x;
  float y;
  float z; } ;

struct facette4 {
  coord3D pt[4] ; } ;

static facette4 f1 = { {{ -5.0F,-3.0F,-3.0F },
                        { -4.0F,-3.5F,4.0F },
                        { 1.0F,-4.5F,3.0F },
                        { 3.0F,-4.75F,-1.0F }} };
static facette4 f2 = { {{ 4.5F,-0.0F,-3.5F },
                        { 2.0F,3.0F,-3.0F },
                        { -2.0F,4.0F,-3.0F },
                        { -1.0F,-1.0F,-4.0F }} };

float produitScalaire(direc3D *v1,direc3D *v2) {
  return(v1->x*v2->x+v1->y*v2->y+v1->z*v2->z);
}

void produitVectoriel(direc3D *v1,direc3D *v2,direc3D *v) {
  v->x = v1->y*v2->z-v2->y*v1->z;
  v->y = v1->z*v2->x-v2->z*v1->x;
  v->z = v1->x*v2->y-v2->x*v1->y;
}

void vecteur(coord3D *p1,coord3D *p2,direc3D *v) {
  v->x = p2->x - p1->x;
  v->y = p2->y - p1->y;
  v->z = p2->z - p1->z;
}

void normalize(direc3D *n) {
  double d =sqrt(n->x*n->x+n->y*n->y+n->z*n->z);
  if ( d != 0.0 ) {
    n->x /= d;
    n->y /= d;
    n->z /= d; }
}

void normale(facette4 *f,direc3D *n) {
  direc3D v1;
  direc3D v2;
  vecteur(&f->pt[0],&f->pt[1],&v1);
  vecteur(&f->pt[0],&f->pt[2],&v2);
  produitVectoriel(&v1,&v2,n);
  normalize(n);
}

void centre(facette4 *f,coord3D *p) {
  p->x = (f->pt[0].x+f->pt[1].x+f->pt[2].x+f->pt[3].x)/4.0F;
  p->y = (f->pt[0].y+f->pt[1].y+f->pt[2].y+f->pt[3].y)/4.0F;
  p->z = (f->pt[0].z+f->pt[1].z+f->pt[2].z+f->pt[3].z)/4.0F;
}

void centrePondere(facette4 *f,coord3D *p,float c0,float c1,float c2,float c3) {
  p->x = (f->pt[0].x*c0+f->pt[1].x*c1+f->pt[2].x*c2+f->pt[3].x*c3)/(c0+c1+c2+c3);
  p->y = (f->pt[0].y*c0+f->pt[1].y*c1+f->pt[2].y*c2+f->pt[3].y*c3)/(c0+c1+c2+c3);
  p->z = (f->pt[0].z*c0+f->pt[1].z*c1+f->pt[2].z*c2+f->pt[3].z*c3)/(c0+c1+c2+c3);
}

void vecteursOrthogonaux(direc3D *d,direc3D *d1,direc3D *d2) {
  d1->x = d->y;
  d1->y = -d->x;
  d1->z = 0.0F;
  normalize(d1);
  produitVectoriel(d,d1,d2);
}

void myinit(void) {
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
  glEnable(GL_AUTO_NORMAL);
  glEnable(GL_NORMALIZE) ;
  glEnable(GL_LIGHT0);
  glEnable(GL_ALPHA_TEST);
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);
  glClearColor(1.0F,1.0F,0.9F,0.0F);
}

void traceFacette4(int type,facette4 *f) {
  glBegin(type);
  for ( int i = 0 ; i < 4 ; i++ )
    glVertex3f(f->pt[i].x,f->pt[i].y,f->pt[i].z);
  glEnd();
}

void axes() {
  setFont(GLUT_BITMAP_8_BY_13,CENTER);
  glColor4fv(couleurRouge());
  flecheEnVolume(1.0F,0.0F,0.0F,0.1F,0.3F,0.02F);
  glColor4fv(couleurVert());
  flecheEnVolume(0.0F,1.0F,0.0F,0.1F,0.3F,0.02F);
  glColor4fv(couleurBleu());
  flecheEnVolume(0.0F,0.0F,1.0F,0.1F,0.3F,0.02F);
  glPushAttrib(GL_DEPTH_TEST);
  glDisable(GL_DEPTH_TEST);
  glColor4fv(couleurRougeFonce());
  bitmapStringOutput(1.3F,0.0F,0.0F,"x");
  glColor4fv(couleurVertFonce());
  bitmapStringOutput(0.0F,1.3F,0.0F,"y");
  glColor4fv(couleurBleuFonce());
  bitmapStringOutput(0.0F,0.0F,1.3F,"z");
  glPopAttrib();
}

void display(void) {
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  direc3D n1;
  direc3D n2;
  coord3D c1;
  coord3D c2;
  normale(&f1,&n1);
  normale(&f2,&n2);
  centre(&f1,&c1);
  centre(&f2,&c2);
  glPushMatrix();
  manipulateurSouris();
  manipulateurClavier();
  glColor4fv(couleurRose(0.4F));
  traceFacette4(GL_QUADS,&f1);
  glClear(GL_DEPTH_BUFFER_BIT);
  { glColor4fv(couleurRoseFonce(0.4F));
    direc3D d1;
    direc3D d2;
    vecteursOrthogonaux(&n1,&d1,&d2);
    glBegin(GL_POLYGON);
    glVertex3f(c1.x+d1.x/2+d2.x/2,c1.y+d1.y/2+d2.y/2,c1.z+d1.z/2+d2.z/2);
    glVertex3f(c1.x+d1.x/2-d2.x/2,c1.y+d1.y/2-d2.y/2,c1.z+d1.z/2-d2.z/2);
    glVertex3f(c1.x-d1.x/2-d2.x/2,c1.y-d1.y/2-d2.y/2,c1.z-d1.z/2-d2.z/2);
    glVertex3f(c1.x-d1.x/2+d2.x/2,c1.y-d1.y/2+d2.y/2,c1.z-d1.z/2+d2.z/2);
    glEnd(); }
  glClear(GL_DEPTH_BUFFER_BIT);
  glColor4fv(couleurBleuCiel(0.4F));
  traceFacette4(GL_QUADS,&f2);
  glClear(GL_DEPTH_BUFFER_BIT);
  { glColor4fv(couleurBleuCielFonce(0.4F));
    direc3D d1;
    direc3D d2;
    vecteursOrthogonaux(&n2,&d1,&d2);
    glBegin(GL_POLYGON);
    glVertex3f(c2.x+d1.x/2+d2.x/2,c2.y+d1.y/2+d2.y/2,c2.z+d1.z/2+d2.z/2);
    glVertex3f(c2.x+d1.x/2-d2.x/2,c2.y+d1.y/2-d2.y/2,c2.z+d1.z/2-d2.z/2);
    glVertex3f(c2.x-d1.x/2-d2.x/2,c2.y-d1.y/2-d2.y/2,c2.z-d1.z/2-d2.z/2);
    glVertex3f(c2.x-d1.x/2+d2.x/2,c2.y-d1.y/2+d2.y/2,c2.z-d1.z/2+d2.z/2);
    glEnd(); }
  glClear(GL_DEPTH_BUFFER_BIT);
  glColor4fv(couleurRouge());
  traceFacette4(GL_LINE_LOOP,&f1);
  { glColor4fv(couleurRougeFonce());
    setAlignement(CENTER);
    coord3D cc;
    centrePondere(&f1,&cc,1.0F,1.0F,1.0F,8.0F);
    placeFontCursor(cc.x,cc.y,cc.z) ;
    simpleBitmapOutput(REGULAR8x13,"A") ;
    deplacementCursor(8,3,0) ;
    simpleBitmapOutput(REGULAR6x10,"i") ; }
  { glColor4fv(couleurRougeFonce());
    setAlignement(CENTER);
    coord3D cc;
    centrePondere(&f1,&cc,1.0F,1.0F,4.0F,1.0F);
    placeFontCursor(cc.x,cc.y,cc.z) ;
    simpleBitmapOutput(REGULAR8x13,"dA") ;
    deplacementCursor(12,3,0) ;
    simpleBitmapOutput(REGULAR6x10,"i") ; }
  glColor4fv(couleurBleu());
  traceFacette4(GL_LINE_LOOP,&f2);
  { glColor4fv(couleurBleuFonce());
    setAlignement(CENTER);
    coord3D cc;
    centrePondere(&f2,&cc,8.0F,1.0F,1.0F,1.0F);
    placeFontCursor(cc.x,cc.y,cc.z) ;
    simpleBitmapOutput(REGULAR8x13,"A") ;
    deplacementCursor(8,3,0) ;
    simpleBitmapOutput(REGULAR6x10,"j") ; }
  { glColor4fv(couleurBleuFonce());
    setAlignement(CENTER);
    coord3D cc;
    centrePondere(&f2,&cc,1.0F,1.0F,1.0F,4.0F);
    placeFontCursor(cc.x,cc.y,cc.z) ;
    simpleBitmapOutput(REGULAR8x13,"dA") ;
    deplacementCursor(12,3,0) ;
    simpleBitmapOutput(REGULAR6x10,"j") ; }
  { glColor4fv(couleurRougeFonce());
    direc3D d1;
    direc3D d2;
    vecteursOrthogonaux(&n1,&d1,&d2);
    glBegin(GL_LINE_LOOP);
    glVertex3f(c1.x+d1.x/2+d2.x/2,c1.y+d1.y/2+d2.y/2,c1.z+d1.z/2+d2.z/2);
    glVertex3f(c1.x+d1.x/2-d2.x/2,c1.y+d1.y/2-d2.y/2,c1.z+d1.z/2-d2.z/2);
    glVertex3f(c1.x-d1.x/2-d2.x/2,c1.y-d1.y/2-d2.y/2,c1.z-d1.z/2-d2.z/2);
    glVertex3f(c1.x-d1.x/2+d2.x/2,c1.y-d1.y/2+d2.y/2,c1.z-d1.z/2+d2.z/2);
    glEnd(); }
  { glColor4fv(couleurBleuFonce());
    direc3D d1;
    direc3D d2;
    vecteursOrthogonaux(&n2,&d1,&d2);
    glBegin(GL_LINE_LOOP);
    glVertex3f(c2.x+d1.x/2+d2.x/2,c2.y+d1.y/2+d2.y/2,c2.z+d1.z/2+d2.z/2);
    glVertex3f(c2.x+d1.x/2-d2.x/2,c2.y+d1.y/2-d2.y/2,c2.z+d1.z/2-d2.z/2);
    glVertex3f(c2.x-d1.x/2-d2.x/2,c2.y-d1.y/2-d2.y/2,c2.z-d1.z/2-d2.z/2);
    glVertex3f(c2.x-d1.x/2+d2.x/2,c2.y-d1.y/2+d2.y/2,c2.z-d1.z/2+d2.z/2);
    glEnd(); }
  glColor4fv(couleurNoir());
  glBegin(GL_LINES);
  glVertex3fv((float *) &c1);
  glVertex3fv((float *) &c2);
  glEnd();
  coord3D c;
  direc3D d;
  c.x = (c1.x+c2.x)/2;
  c.y = (c1.y+c2.y)/2;
  c.z = (c1.z+c2.z)/2;
  d.x = c1.x - c2.x;
  d.y = c1.y - c2.y;
  d.z = c1.z - c2.z;
  { setAlignement(CENTER);
    placeFontCursor(c.x-c.y/3,c.y+c.x/3,c.z) ;
    simpleBitmapOutput(REGULAR8x13,"r") ;
    glPushMatrix();
    glTranslatef(c.x-c.y/3+d.x/20,c.y+c.x/3+d.y/20,c.z+d.z/20) ;
    flecheEnFilaire(d.x/5,d.y/5,d.z/5,0.08F,0.2F);
    glPopMatrix();
    glPushMatrix();
    glTranslatef(c.x-c.y/3-d.x/20,c.y+c.x/3-d.y/20,c.z-d.z/20) ;
    flecheEnFilaire(-d.x/5,-d.y/5,-d.z/5,0.08F,0.2F);
    glPopMatrix(); }
  { setAlignement(CENTER);
    coord3D ct;
    ct.x = c1.x+(n1.x*1.5-d.x/4)/2;
    ct.y = c1.y+(n1.y*1.5-d.y/4)/2;
    ct.z = c1.z+(n1.z*1.5-d.z/4)/2;
    placeFontCursor(ct.x,ct.y,ct.z) ;
    deplacementCursor(-2,-2,0) ;
    simpleBitmapOutput(SYMBOL,"q") ;
    deplacementCursor(4,1,0) ;
    simpleBitmapOutput(REGULAR6x10,"i") ; }
  { setAlignement(CENTER);
    coord3D ct;
    ct.x = c2.x+(n2.x*2+d.x/3)/2;
    ct.y = c2.y+(n2.y*2+d.y/3)/2;
    ct.z = c2.z+(n2.z*2+d.z/3)/2;
    placeFontCursor(ct.x,ct.y,ct.z) ;
    deplacementCursor(-2,-2,0) ;
    simpleBitmapOutput(SYMBOL,"q") ;
    deplacementCursor(4,1,0) ;
    simpleBitmapOutput(REGULAR6x10,"j") ; }
  { glColor4fv(couleurRouge());
    glPushMatrix();
    glTranslatef(c1.x,c1.y,c1.z);
    flecheEnVolume(n1.x*3,n1.y*3,n1.z*3,0.1F,0.3F,0.02F);
    glPopMatrix();
    glColor4fv(couleurRougeFonce());
    setAlignement(LEFT);
    placeFontCursor(c1.x+n1.x*2.5,c1.y+n1.y*2.5,c1.z+n1.z*2.5) ;
    deplacementCursor(5,0,0) ;
    simpleBitmapOutput(REGULAR8x13,"N") ;
    deplacementCursor(15,3,0) ;
    simpleBitmapOutput(REGULAR6x10,"i") ;
    deplacementCursor(4,-5,0) ;
    simpleBitmapOutput(DESSIN,"TF") ; }
  { glColor4fv(couleurBleu());
    glPushMatrix();
    glTranslatef(c2.x,c2.y,c2.z);
    flecheEnVolume(n2.x*3,n2.y*3,n2.z*3,0.1F,0.3F,0.02F);
    glPopMatrix();
    glColor4fv(couleurBleuFonce());
    setAlignement(LEFT);
    placeFontCursor(c2.x+n2.x*3,c2.y+n2.y*3,c2.z+n2.z*3) ;
    deplacementCursor(5,-13,0) ;
    simpleBitmapOutput(REGULAR8x13,"N") ;
    deplacementCursor(15,-10,0) ;
    simpleBitmapOutput(REGULAR6x10,"j") ;
    deplacementCursor(4,-18,0) ;
    simpleBitmapOutput(DESSIN,"TF") ; }
  { glPushMatrix();
    glTranslatef(-4.5F,3.0F,1.5F);
    axes();
    glPopMatrix(); }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGBA|GLUT_DEPTH);
  glutInitWindowPosition(10,10);
  glutInitWindowSize(300,300);
  glutCreateWindow("Facteur de forme en radiosite");
  myinit();
  creationMenuBasique();
  setParametresOrthoBasique(-6.0,6.0,-6.0,6.0,-500.0,500.0);
  setManipulateurDistance(1.0F);
  setManipulateurClavierAngle(20.0F,-60.0F,0.0F) ;
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(keyBasique);
  glutSpecialFunc(specialBasique);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}

/* ************************************************** */