shadowing-vis.cc

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/* -*-  Mode:C++; c-basic-offset:8; tab-width:8; indent-tabs-mode:t -*- */

/*
 * shadowing-vis.cc
 * Copyright (C) 2000 by the University of Southern California
 * $Id: shadowing-vis.cc,v 1.6 2005/08/25 18:58:09 johnh Exp $
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 *
 * The copyright of this module includes the following
 * linking-with-specific-other-licenses addition:
 *
 * In addition, as a special exception, the copyright holders of
 * this module give you permission to combine (via static or
 * dynamic linking) this module with free software programs or
 * libraries that are released under the GNU LGPL and with code
 * included in the standard release of ns-2 under the Apache 2.0
 * license or under otherwise-compatible licenses with advertising
 * requirements (or modified versions of such code, with unchanged
 * license).  You may copy and distribute such a system following the
 * terms of the GNU GPL for this module and the licenses of the
 * other code concerned, provided that you include the source code of
 * that other code when and as the GNU GPL requires distribution of
 * source code.
 *
 * Note that people who make modified versions of this module
 * are not obligated to grant this special exception for their
 * modified versions; it is their choice whether to do so.  The GNU
 * General Public License gives permission to release a modified
 * version without this exception; this exception also makes it
 * possible to release a modified version which carries forward this
 * exception.
 *
 */

/*
 * Visibility-Shadowing propation model. It has 2 shadowing model instances
 * that represent good (has line-of-sight path) and bad (obstructed)
 * propagation conditions.
 * Wei Ye, weiye@isi.edu, 2000
 */

#include "config.h"

#include <math.h>
#include <fstream>


#include <delay.h>
#include <packet.h>
#include <packet-stamp.h>
#include <antenna.h>
#include <mobilenode.h>
#include <propagation.h>
#include <wireless-phy.h>
#include <shadowing-vis.h>

#define BLACK 0
//#define WHITE 0xff

//#define DEBUG

static class ShadowingVisClass: public TclClass {
public:
    ShadowingVisClass() : TclClass("Propagation/ShadowingVis") {}
    TclObject* create(int, const char*const*) {
        return (new ShadowingVis);
    }
} class_visibility_shadowing;


ShadowingVis::ShadowingVis()
{
    goodProp = NULL;
    badProp = NULL;
}


double ShadowingVis::Pr(PacketStamp *t, PacketStamp *r, WirelessPhy *ifp)
{

    double Xt, Yt, Zt;      // loc of transmitter
    double Xr, Yr, Zr;      // loc of receiver
    double Pr;          // received signal power

    t->getNode()->getLoc(&Xt, &Yt, &Zt);
    r->getNode()->getLoc(&Xr, &Yr, &Zr);

    // Is antenna position relative to node position?
    Xt += t->getAntenna()->getX();
    Yt += t->getAntenna()->getY();
    Xr += r->getAntenna()->getX();
    Yr += r->getAntenna()->getY();
        
    // Since we use a bitmap, it's a 2-d environment.
    // So Zt and Zr are omitted.
    
    //get propagation conidition between T/R
    int propCond = getPropCond(Xt, Yt, Xr, Yr);
    if (propCond == 1) {
        Pr = goodProp->Pr(t, r, ifp);
#ifdef DEBUG
        printf("Good propagation condition!\n");
#endif
    } else {
        Pr = badProp->Pr(t, r, ifp);
#ifdef DEBUG
        printf("Bad propagation condition!\n");
#endif
    }
        
    return Pr;
}


int ShadowingVis::command(int argc, const char*const* argv)
{
    TclObject *obj;
    
    if (argc == 3) {
        if (strcmp(argv[1], "get-bitmap") == 0) {
            loadImg(argv[2]);
            return(TCL_OK);
        }
        if (strcmp(argv[1], "set-ppm") == 0) {
            ppm = atoi(argv[2]);
            return(TCL_OK);
        }
    }
    if (argc == 4) {
        if (strcmp(argv[1], "add-models") == 0) {
            if( (obj = TclObject::lookup(argv[2])) == 0) {
                fprintf(stderr, "ShadowingVis: %s lookup of %s failed\n", \
                    argv[1], argv[2]);
                return TCL_ERROR;
            } else {
                goodProp = (Shadowing*) obj;
            }
            if( (obj = TclObject::lookup(argv[3])) == 0) {
                fprintf(stderr, "ShadowingVis: %s lookup of %s failed\n", \
                    argv[1], argv[3]);
                return TCL_ERROR;
            } else {
                badProp = (Shadowing*) obj;
            }
            return(TCL_OK);
        }
    }
    
    return Propagation::command(argc, argv);
}


void ShadowingVis::loadImg(const char* fname)
{
#ifdef DEBUG
    printf("loading %s\n", fname);
#endif

    ifstream image( fname );

    char magicNumber[10];
    char comment[256];
    int whiteNum;
    char terminator;

    if( image.fail() ) printf("image bad!\n");

    if( strstr( fname, ".pnm" ) ) {
        image >> magicNumber;
        image.get( terminator );
        image.get( comment, 255, '\n');
        image.get( terminator );
        image >> width >> height >> whiteNum;
    } else if( strstr( fname, ".pgm" ) ) {
        image >> magicNumber;
        image.get( terminator );
        image >> width >> height >> whiteNum;
    }

#ifdef DEBUG
    printf("magic: %s\ncomment: %s\nwidth: %d height: %d white: %d\n", magicNumber, comment, width, height, whiteNum);
#endif

    pixel = new unsigned char[width * height];
    //unsigned char a;   #Sun OS compilation Fix - fcartegn@univ-valenciennes.fr - Apr 26 02
    char a;
    image.get(a);   // this byte is not the image

    // the upper-left corner is the origin (0, 0)
    for(int n = 0; n < height; n++) {
        for(int m = 0; m < width; m++) {
            image.get( a );
            pixel[m + n * width] = a;
        }
    }

#ifdef DEBUG
    FILE *testFile;
    char *filename = "imgtest.hex";
    testFile = fopen(filename, "w");
    for (int n = 0; n < height; n++) {
      for (int m = 0; m < width; m++)
        if (pixel[m + n * height] == BLACK)
            fprintf(testFile, "%x", pixel[m + n * height]);
        else
            fprintf(testFile, "%x", 0xf);
        fprintf(testFile, "\n");
    }
    fclose(testFile);
#endif

    image.close();
}


int ShadowingVis::getPropCond(float xt, float yt, float xr, float yr)
{
#ifdef DEBUG
    printf("xt = %f yt = %f xr = %f yr = %f\n", xt, yt, xr, yr);
#endif
    float dx = xr - xt;
    float dy = yr - yt;
    float maxDistSq = dx * dx + dy * dy;
    float maxDist = sqrt(maxDistSq);
    dx /= maxDist;
    dy /= maxDist;
    maxDistSq = (float)(ppm * ppm) * maxDistSq;

    float xtPxl = (float)ppm * xt;
    float ytPxl = (float)ppm * yt;

    // Now each time there is only one pixel is test along the line from
    // the transmitter to the receiver. If ppm is large, more pixels 
    // can be tested: if the line of sight path is just obstructed by
    // a very small object, the propagation is still good
    int goodProp = 1;
/*
    float distSq = 0; 
    while (distSq < maxDistSq) {
        int xIdx = (int)(xx * ppm);
        int yIdx = (int)(yy * ppm);
        if ( pixel[xIdx + yIdx * width] != BLACK ) {
            goodProp = 0;
#ifdef DEBUG
            cout << "xx = " << xx << " yy = " << yy << endl;
            printf("pixel = %x\n", pixel[xIdx + yIdx * width]);
#endif
            break;
        }
        xx += dx;
        yy += dy;
        distSq = (xx - xt) * (xx - xt) + (yy - yt) * (yy - yt);
    }
*/
/*
    int maxRange = (int)(maxDist * ppm); // distance times pixels-per-meter
    for (int rng = 0; rng < maxRange; rng++) {
        if (pixel[(int)xx + (int)yy * width] != BLACK) {
#ifdef DEBUG
            cout << "xx = " << xx << " yy = " << yy << endl;
            printf("pixel = %x\n", pixel[(int)xx + (int)yy * width]);
#endif
            goodProp = 0;
            break;
        }
        xx += dx;
        yy += dy;
    }
*/
    
    float distX = 0;
    float distY = 0;
    float distSq = 0;
    while (distSq < maxDistSq) {
        int xIdx = (int)(xtPxl + distX);
        int yIdx = (int)(ytPxl + distY);
        if (pixel[xIdx + yIdx * width] != BLACK) {
            goodProp = 0;
#ifdef DEBUG
            printf("xx = %f  yy = %f\n", xx, yy);
            printf("pixel = %x\n", pixel[xIdx + yIdx * width]);
#endif
            break;
        }
        distX += dx;
        distY += dy;
        distSq = distX * distX + distY * distY;
    }
    
    return goodProp;
}

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