/****************************************************************************
**
** This file is part of the LibreCAD project, a 2D CAD program
**
** Copyright (C) 2010 R. van Twisk (librecad@rvt.dds.nl)
** Copyright (C) 2001-2003 RibbonSoft. All rights reserved.
**
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file gpl-2.0.txt included in the
** packaging of this file.
**
** 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
**
** This copyright notice MUST APPEAR in all copies of the script!
**
**********************************************************************/

#include <QPolygon>
#include "rs_infoarea.h"

#include "rs_math.h"
#include "rs_debug.h"


/**
 * Constructor.
 */
RS_InfoArea::RS_InfoArea() {
    calculationNeeded=true;
}



/**
 * Destructor.
 */
RS_InfoArea::~RS_InfoArea() {}



/**
 * Adds a point to the internal list
 *
 * @param p co-ordinate of the point
 */
void RS_InfoArea::push_back(const RS_Vector& p) {
    if (thePoints.empty()) {
        baseY = p.y;
    }

    thePoints.push_back(p);
    calculationNeeded=true;
}

//remove the last point
void RS_InfoArea::pop_back() {
    thePoints.pop_back();
    calculationNeeded=true;
}

/**
 * Resets the points.
 */
void RS_InfoArea::reset() {
    thePoints.clear();
    area = 0.0;
    circumference = 0.0;
}


/**
  * whether a point is already in contour
  *@return true if the point is a duplicate
  *@return false if the point is not in contour
  **/
bool RS_InfoArea::duplicated(const RS_Vector& p){
    if(thePoints.size()<1) return false;
    for(int i=0;i<thePoints.size();i++){
        if( (thePoints.at(i)-p).squared() < RS_TOLERANCE2) {
            return true;
        }
    }
    return false;
}


/**
 * Calculates the area and the circumference of the area.
 */
void RS_InfoArea::calculate() {
    area = 0.0;
    circumference = 0.0;
    if(thePoints.size()<3) return;

    RS_Vector p1=thePoints.first();
    for(int i=0;i<thePoints.size();i++){
//        std::cout<<"RS_InfoArea::calculate(): "<<i<<" , "<<p1<<std::endl;
        RS_Vector p2=thePoints.at( (i+1)%thePoints.size());
        area += calcSubArea(p1, p2);
        circumference += p1.distanceTo(p2);
        p1=p2;
    }

    area = 0.5*fabs(area);
    calculationNeeded=false;
}

double RS_InfoArea::getArea(const QPolygon& polygon)
{
    double ret= 0.0;
    if(polygon.size()<3) return ret;

    for(int i=0;i<polygon.size(); ++i){
        const QPoint& p0=polygon.at(i);
        const QPoint& p1=polygon.at((i+1)%polygon.size());
        ret += p0.x()*p1.y()-p0.y()*p1.x();
    }
    return 0.5*fabs(ret);
}



/**
 * Calculates a sub area.
 *
 * @param p1 first point
 * @param p2 second point
 */
double RS_InfoArea::calcSubArea(const RS_Vector& p1, const RS_Vector& p2) {
    double width = p2.x - p1.x;
    double height = (p1.y - baseY) + (p2.y - baseY);

    return width * height ; //moved a factor of 0.5 to calculate()
}



// EOF
