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**
** 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.h"
#include "rs_infoarea.h"
/**
* Constructor.
*/
RS_InfoArea::RS_InfoArea():
calculationNeeded(true){
}
/**
* Adds a point to the internal list
*
* @param p coordinate of the point
*/
void RS_InfoArea::push_back(const RS_Vector &p){
if (m_points.empty()){
baseY = p.y;
}
m_points.push_back(p);
calculationNeeded = true;
}
//remove the last point
void RS_InfoArea::pop_back(){
m_points.pop_back();
calculationNeeded = true;
}
/**
* Resets the points.
*/
void RS_InfoArea::reset(){
m_points.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 (m_points.size() < 1) return false;
for (const RS_Vector &v: m_points) {
if ((v - 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 (m_points.size() < 3) return;
RS_Vector p1 = m_points.front();
for (size_t i = 0; i < m_points.size(); ++i) {
// std::cout<<"RS_InfoArea::calculate(): "<<i<<" , "<<p1<<std::endl;
RS_Vector p2 = m_points.at((i + 1) % m_points.size());
area += calcSubArea(p1, p2);
circumference += p1.distanceTo(p2);
p1 = p2;
}
area = 0.5 * std::abs(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 * std::abs(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()
}
// ---------------------------------//
double RS_InfoArea::getArea() const{
return area;
}
// ---------------------------------//
double RS_InfoArea::getCircumference(){
if (calculationNeeded)
calculate();
return circumference;
}
// ---------------------------------//
int RS_InfoArea::size(){
if (calculationNeeded)
calculate();
return m_points.size();
}
// ---------------------------------//
const RS_Vector &RS_InfoArea::at(int i) const{
return m_points.at(i);
}
// ---------------------------------//
RS_Vector &RS_InfoArea::at(int i) {
return m_points.at(i);
}
// ---------------------------------//
const RS_Vector &RS_InfoArea::back() const{
return m_points.back();
}
// ---------------------------------//
RS_Vector &RS_InfoArea::back() {
return m_points.back();
}
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