/* -*-	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 1.8 2010/04/30 17:10:38 tom_henderson 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 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;
			break;
		}
		distX += dx;
		distY += dy;
		distSq = distX * distX + distY * distY;
	}
	
	return goodProp;
}


double ShadowingVis::getDist(double , double , double , double , double , double , double , double )
{
	return DBL_MAX;
}