vpCoreDisplay.cpp

/****************************************************************************
 *
 * This file is part of the ViSP software.
 * Copyright (C) 2005 - 2017 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * ("GPL") version 2 as published by the Free Software Foundation.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See http://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Le module "display.c" contient les procedures de d'affichage
 * des scenes de modele geometrique surfacique.
 *
 * Authors:
 * Jean-Luc CORRE
 *
 *****************************************************************************/




#include <visp3/core/vpConfig.h>

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


#include "vpMy.h"
#include "vpCoreDisplay.h"
#include "vpView.h"
#include "vpImstack.h"
#include "vpRfstack.h"
#include "vpVwstack.h"


/*
 * POINT2I  : 
 * Tableau de points 2D dans l'espace ecran servant a l'affichage fil-de-fer.
 *
 * RENAME   :
 * Tableau de renommage des sommets ou tableau de compteurs associes aux points.
 */
Point2i *point2i = (Point2i *) NULL;
Point2i *listpoint2i = (Point2i *) NULL;
static  int *rename_jlc  = (int *) NULL;


/*
 * La procedure "open_display" alloue et initialise les variables utilisees
 * par le mode "display".
 */
void open_display (void)
{
  if ((point2i = (Point2i *) malloc (POINT_NBR*sizeof (Point2i))) == NULL
  || (listpoint2i = (Point2i *) malloc (50*sizeof (Point2i))) == NULL
  || (rename_jlc  = (int *) malloc (POINT_NBR * sizeof (int))) == NULL)
  {
    static  char    proc_name[] = "open_display";
    perror (proc_name);
    exit (1);
  }
}

/*
 * La procedure "close_display" libere les variables utilisees par le mode
 * "display".
 */
void close_display (void)
{
  free ((char *) point2i);
  free ((char *) listpoint2i);
  free ((char *) rename_jlc);
  point2i = (Point2i *) NULL;
  listpoint2i = (Point2i *) NULL;
  rename_jlc  = (int *) NULL;
}

/*
 * La procedure "point_3D_2D" projette les points 3D du volume canonique
 * dans l'espace image 2D.
 *
 *  Volume canonique    Espace image
 *  ________________    ____________
 *
 *  - 1 < X < 1     0 < X < xsize
 *  - 1 < Y < 1     0 < Y < ysize
 *    0 < Z < 1
 *
 *        Z < 0     X = 0, Y = -1 non significatifs.
 *
 * Entree :
 * p3       Tableau de points 3D a projeter.
 * size     Taille du tableau de points "p3".
 * xsize, ysize Tailles de l'espace image.
 * p2       Tableau de points 2D en sortie.
 */
// static
void point_3D_2D (Point3f *p3, Index size, int xsize, int ysize, Point2i *p2)
{
    Point3f *pend = p3 + size;  /* borne de p3  */
    float       xdiv2 = ((float) xsize) / (float)2.0;
    float       ydiv2 = ((float) ysize) / (float)2.0;

    for (; p3 < pend; p3++, p2++) {
        p2->x = (int) ((1.0 + p3->x) * xdiv2);
        p2->y = (int) ((1.0 - p3->y) * ydiv2);
    }
}

/*
 * La procedure "set_Bound_face_display" marque les faces affichables
 * de la surface "bp".
 * Soit la face comportant le contour oriente suivant : (...,P2,P0,P1...).
 * La normale a la face au point P0 est obtenue par le produit vectoriel :
 * 
 *              | x1 - x0   x2 - x0 |   | Nx |
 * N = (P1 - P0) ^ (P2 - P0) =  | y1 - y0   y2 - y0 | = | Ny |
 *              | z1 - z0   z2 - z0 |   | Nz |
 *
 * La face est dans le volume canonique de vision et dans un repere gauche.
 * L'observateur est situe a l'infini dans la direction [0, 0, -1].
 * IS_ABOVE <=> Ny < 0,     IS_BELOW    <=> Ny > 0.
 * IS_RIGHT <=> Nx < 0,     IS_LEFT     <=> Nx > 0.
 * IS_BACK  <=> Nz < 0,     IS_FRONT    <=> Nz > 0.
 * Entree :
 * bp       Surface a initialiser.
 * b        Drapeaux indiquant les faces non affichables.
 */
void set_Bound_face_display (Bound *bp, Byte b)
{
    Face        *fp   = bp->face.ptr;
    Face        *fend = fp + bp->face.nbr;
    Point3f *pp   = bp->point.ptr;

    for (; fp < fend; fp++) {
        Index    *vp;
        Point3f *p0;    /* premier sommet   */
        Point3f *p1;    /* second  sommet   */
        Point3f *p2;    /* dernier sommet   */

        fp->is_visible = TRUE;
        if (b == IS_INSIDE) continue;
        vp = fp->vertex.ptr;
        p0 = pp + *vp;  
        p1 = pp + *(vp + 1);
        p2 = pp + *(vp + fp->vertex.nbr - 1);
        if (b & IS_ABOVE) {
            fp->is_visible =  ((p1->z - p0->z) * (p2->x - p0->x) 
                    >= (p1->x - p0->x) * (p2->z - p0->z));
        }
        if (! fp->is_visible) continue;
        if (b & IS_BELOW) {
            fp->is_visible =  ((p1->z - p0->z) * (p2->x - p0->x) 
                    <= (p1->x - p0->x) * (p2->z - p0->z));
        }
        if (! fp->is_visible) continue;
        if (b & IS_RIGHT) {
            fp->is_visible =  ((p1->y - p0->y) * (p2->z - p0->z) 
                    >= (p1->z - p0->z) * (p2->y - p0->y));
        }
        if (! fp->is_visible) continue;
        if (b & IS_LEFT) {
            fp->is_visible =  ((p1->y - p0->y) * (p2->z - p0->z) 
                    <= (p1->z - p0->z) * (p2->y - p0->y));
        }
        if (! fp->is_visible) continue;
        if (b & IS_BACK) {
            fp->is_visible =  ((p1->x - p0->x) * (p2->y - p0->y) 
                    >= (p1->y - p0->y) * (p2->x - p0->x));
        }
        if (! fp->is_visible) continue;
        if (b & IS_FRONT) {
            fp->is_visible =  ((p1->x - p0->x) * (p2->y - p0->y) 
                    <= (p1->y - p0->y) * (p2->x - p0->x));
        }
    }
}


/*
 * La procedure "wireframe_Face" affiche une face "fp" en "fil de fer".
 * sur la fenetre graphique de "suncgi" sur "SUN".
 * Les points des sommets de la face sont contenu dans les points "pp" 
 * de la surface contenant la face.
 * Entree :
 * fp       face a afficher.
 * pp       Points de la surface contenant la face.
 */
void wireframe_Face (Face *fp, Point2i *pp)
{
//  extern Window id_window;

    Index   *vp   = fp->vertex.ptr;
    Index   *vend = vp + fp->vertex.nbr;
    Point2i *cp   = listpoint2i;

    if (fp->vertex.nbr < 2) return;
    if (fp->vertex.nbr > 50)
    {
        printf("pb malloc listpoint2i (display.c)\n"); return;
    }
    for (; vp < vend; vp++, cp++) { 
        SET_COORD2(*cp,  pp[*vp].x,  pp[*vp].y);
    } 
}

#endif