/* Auteur: Nicolas JANEY         */
/* nicolas.janey@univ-fcomte.fr  */
/* Fevrier 2019                  */
/* Assemblage de deux courbes    */
/* de Bezier a quatre sommets    */

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

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

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

struct coord_3D {
  GLfloat x = 0.0F;
  GLfloat y = 0.0F;
  GLfloat z = 0.0F;
  GLfloat w = 1.0F; };

struct polygone {
  int n = 0;
  coord_3D *p = NULL; };

typedef struct coord_3D coord_3D;
typedef struct polygone polygone;
typedef float matrice[4][4];

static GLfloat pts[7][4] = { 
  { -4.0F,-2.0F, 4.0F, 1.0F },
  { -7.0F, 0.0F, 2.0F, 1.0F},
  { -2.0F, 3.0F,-2.0F, 1.0F}, 
  { -1.0F, 0.0F,-1.0F, 1.0F}, 
  {  0.0F,-3.0F, 0.0F, 1.0F}, 
  {  3.0F,-4.0F,-4.0F, 1.0F}, 
  {  5.0F, 2.0F, 4.0F, 1.0F}};

static int pt = 0;
static int mode = 0;
static int disc = 30;

static matrice mbezier =
  { -1.0F, 3.0F,-3.0F, 1.0F,
     3.0F,-6.0F, 3.0F, 0.0F,
    -3.0F, 3.0F, 0.0F, 0.0F,
     1.0F, 0.0F, 0.0F, 0.0F };

static polygone pl1;
static polygone pl2;

void point(float x,float y,float z) {
  glVertex3f(x,y,z);
}

void tangente(coord_3D *p,int n,matrice m,float t,float *tx,float *ty,float *tz) { 
  int j,k;
  float tt[3],ttt[4],x,y,z;
  tt[0] = 3*t*t;
  tt[1] = 2*t;
  tt[2] = 1.0F;
  for ( j = 0 ; j < 4 ; j++ )
    for ( k = 0,ttt[j] = 0 ; k < 3 ; k++ )
      ttt[j] += tt[k] * m[k][j];
  x = y = z = 0;
  for ( j = 0 ; j < 4 ; j++ ) {
    x += ttt[j] * p[j].x;
    y += ttt[j] * p[j].y;
    z += ttt[j] * p[j].z; }
  float d =(float) pow((double) (x*x+y*y+z*z),0.5);
  *tx = x/d;
  *ty = y/d;
  *tz = z/d;
}

void morceauBezier(coord_3D *p,int n,matrice m) { 
  int j,k;
  float tt[4],ttt[4],x,y,z;
  for ( int i = 0 ; i < n ; i++ ) {
    float t =(float) i/(n-1);
    tt[0] = t*t*t;
    tt[1] = t*t;
    tt[2] = t;
    tt[3] = 1;
    for ( j = 0 ; j < 4 ; j++ )
      for ( k = 0,ttt[j] = 0 ; k < 4 ; k++ )
        ttt[j] += tt[k] * m[k][j];
    x = y = z = 0;
    for ( j = 0 ; j < 4 ; j++ ) {
      x += ttt[j] * p[j].x;
      y += ttt[j] * p[j].y;
      z += ttt[j] * p[j].z; }
    point(x,y,z); }
}

void display(void) { 
  int i;
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glEnable(GL_DEPTH_TEST);
  manipulateurSouris();
  manipulateurClavier();
  glColor4fv(couleurBlanc());
  glBegin(GL_LINE_STRIP);
  for ( i = 0 ; i < 7 ; i++ ) 
    glVertex3fv(&pts[i][0]);
  glEnd();
  glPointSize(5.0);
  glBegin(GL_POINTS);
  for ( i = 0 ; i < 7 ; i++ ) {
    glColor4fv((i == pt) ? couleurRouge() : couleurJaune());
    glVertex3fv(&pts[i][0]); }
  glEnd();
  glPointSize(3.0);
  if ( ( mode == 0 ) || ( mode == 2 ) ) {
    glColor4fv(couleurCyan());
    glBegin(GL_LINE_STRIP);
    morceauBezier(pl1.p,disc,mbezier);
    glEnd();
    glBegin(GL_LINE_STRIP);
    morceauBezier(pl2.p,disc,mbezier);
    glEnd(); }
  if ( ( mode == 1 ) || ( mode == 2 ) ) {
    glColor4fv(couleurMagenta());
    glBegin(GL_POINTS);
    morceauBezier(pl1.p,disc,mbezier);
    glEnd();
    glBegin(GL_POINTS);
    morceauBezier(pl2.p,disc,mbezier);
    glEnd(); }
  glDisable(GL_DEPTH_TEST);
  for ( i = 0 ; i < 7 ; i++ )  {
    glColor4fv((i == pt) ? couleurRouge() : couleurJaune());
    placeFontCursor(pts[i][0]+0.3F,pts[i][1]+0.3F,pts[i][2]+0.3F);
    simpleBitmapOutput("%d",i); }
  glPopMatrix();
  float xmin = getXmin();
  float ymin = getYmin();
  float ymax = getYmax();
  float tpix = getTaillePixel();
  setAntialiased(1);
  setBold(1);
  setEcartementCaracteres(25.0F);
  glPushMatrix();
  glColor4fv(couleurBlanc());
  strokeOutput(xmin+0.1F,ymax-0.7F,1.0F,"V1: %f %f %f",pts[3][0]-pts[2][0],pts[3][1]-pts[2][1],pts[3][2]-pts[2][2]);
  strokeOutput(xmin+0.1F,ymax-1.7F,1.0F,"V2: %f %f %f",pts[4][0]-pts[3][0],pts[4][1]-pts[3][1],pts[4][2]-pts[3][2]);
  float tx;
  float ty;
  float tz;
  tangente(pl1.p,disc,mbezier,1.0F,&tx,&ty,&tz);
  strokeOutput(xmin+0.1F,ymin+1.5F,1.0F,"T1: %f %f %f",tx,ty,tz);
  tangente(pl2.p,disc,mbezier,0.0F,&tx,&ty,&tz);
  strokeOutput(xmin+0.1F,ymin+0.5F,1.0F,"T2: %f %f %f",tx,ty,tz);
  glPopMatrix();
  setAntialiased(0);
  setBold(0);
  setEcartementCaracteres(0.0F);
  glFlush();
  glutSwapBuffers();
} 

void init(void) { 
  glClearColor(0.0,0.0,0.0,1.0);
} 
  
void special(int k, int x, int y) {
  switch (k) {
    case GLUT_KEY_LEFT      : pts[pt][0]-= 0.1F;
                              glutPostRedisplay();
                              break;
    case GLUT_KEY_RIGHT     : pts[pt][0] += 0.1F;
                              glutPostRedisplay();
                              break;
    case GLUT_KEY_UP        : pts[pt][1] += 0.1F;
                              glutPostRedisplay();
                              break;
    case GLUT_KEY_DOWN      : pts[pt][1] -= 0.1F;
                              glutPostRedisplay();
                              break;
    case GLUT_KEY_PAGE_UP   : pts[pt][2] -= 0.1F;
                              glutPostRedisplay();
                              break;
    case GLUT_KEY_PAGE_DOWN : pts[pt][2] += 0.1F;
                              glutPostRedisplay();
                              break; }
}

void key(unsigned char key,int x,int y) {
  if ( keyManipulateur(key,x,y) )
    glutPostRedisplay();
    else
    switch ( key ) {
    case 43     : disc++;
                  glutPostRedisplay();
                  break;
    case 45     : disc--;
                  if ( disc < 3 )
                    disc = 3;
                  glutPostRedisplay();
                  break;
    case 'a'    : mode = (mode+1)%3;
                  glutPostRedisplay();
                  break;
    case 32     : pt = (pt+1)%4;
                  glutPostRedisplay();
                  break; }
}

void select2(int selection) {
  switch (selection) {
    case 4  : pt = (pt+1)%4;
              glutPostRedisplay();
              break;
    case 5  : mode = 0;
              glutPostRedisplay();
              break;
    case 6  : mode = 1;
              glutPostRedisplay();
              break;
    case 7  : mode = 2;
              glutPostRedisplay();
              break; }
}

void select3(int selection) {
  switch (selection) {
    case 10 : disc = 3;
              glutPostRedisplay();
              break;
    case 11 : disc = 10;
              glutPostRedisplay();
              break;
    case 12 : disc = 30;
              glutPostRedisplay();
              break;
    case 13 : disc = 50;
              glutPostRedisplay();
              break;
    case 14 : disc = 100;
              glutPostRedisplay();
              break;
    case 6  : disc++;
              glutPostRedisplay();
              break;
    case 7  : disc--;
              if ( disc < 3 )
                disc = 3;
              glutPostRedisplay();
              break; }
}

void select(int selection) {
  switch (selection) {
    case 0  : exit(0); }
}

void creationMenu(void) {
  int menu2 = glutCreateMenu(select2);
  glutAddMenuEntry("Changer point",4);
  glutAddMenuEntry("Fil de fer",5);
  glutAddMenuEntry("Points",6);
  glutAddMenuEntry("Fil de fer et points",7);
  int menu3 = glutCreateMenu(select3);
  glutAddMenuEntry("3",10);
  glutAddMenuEntry("10",11);
  glutAddMenuEntry("30",12);
  glutAddMenuEntry("50",13);
  glutAddMenuEntry("100",14);
  glutAddMenuEntry("Augmenter",6);
  glutAddMenuEntry("Reduire",7);
  glutCreateMenu(select);
  glutAddSubMenu("Affichage",menu2);
  glutAddSubMenu("Discretisation",menu3);
  glutAddMenuEntry("Quitter",0);
  glutAttachMenu(GLUT_RIGHT_BUTTON);
}

int main(int argc,char **argv) {

  pl1.n = 4;
  pl1.p =(coord_3D *) &pts[0][0];
  pl2.n = 4;
  pl2.p =(coord_3D *) &pts[3][0];

  glutInit(&argc,argv);
  glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
  glutInitWindowSize(300,300);
  glutInitWindowPosition(50,50);
  glutCreateWindow("Assemblage de courbes de Bezier");
  init();
  creationMenu();
  setParametresOrthoBasique(-8.0,8.0,-8.0,8.0,-100.0,100.0);
  setManipulateurDistance(1.0F);
  glutReshapeFunc(reshapeOrthoBasique);
  glutKeyboardFunc(key);
  glutSpecialFunc(special);
  glutMotionFunc(motionBasique);
  glutMouseFunc(sourisBasique);
  glutDisplayFunc(display);
  glutMainLoop();
  return(0);
}