149 lines
3.6 KiB
C++
149 lines
3.6 KiB
C++
/****************************************************************************
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**
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** This file is part of the LibreCAD project, a 2D CAD program
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**
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** Copyright (C) 2010 R. van Twisk (librecad@rvt.dds.nl)
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** Copyright (C) 2001-2003 RibbonSoft. All rights reserved.
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**
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**
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** This file may be distributed and/or modified under the terms of the
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** GNU General Public License version 2 as published by the Free Software
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** Foundation and appearing in the file gpl-2.0.txt included in the
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** packaging of this file.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program; if not, write to the Free Software
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** Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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**
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** This copyright notice MUST APPEAR in all copies of the script!
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**
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**********************************************************************/
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#include<cmath>
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#include <QPolygon>
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#include "rs_infoarea.h"
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#include "rs_math.h"
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#include "rs_debug.h"
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/**
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* Constructor.
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*/
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RS_InfoArea::RS_InfoArea():
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calculationNeeded(true)
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{
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}
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/**
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* Adds a point to the internal list
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*
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* @param p coordinate of the point
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*/
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void RS_InfoArea::push_back(const RS_Vector& p) {
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if (thePoints.empty()) {
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baseY = p.y;
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}
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thePoints.push_back(p);
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calculationNeeded=true;
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}
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//remove the last point
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void RS_InfoArea::pop_back() {
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thePoints.pop_back();
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calculationNeeded=true;
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}
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/**
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* Resets the points.
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*/
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void RS_InfoArea::reset() {
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thePoints.clear();
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area = 0.0;
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circumference = 0.0;
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}
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/**
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* whether a point is already in contour
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*@return true if the point is a duplicate
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*@return false if the point is not in contour
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**/
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bool RS_InfoArea::duplicated(const RS_Vector& p){
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if(thePoints.size()<1) return false;
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for(const RS_Vector& v: thePoints){
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if((v-p).squared()<RS_TOLERANCE2) return true;
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}
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return false;
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}
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/**
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* Calculates the area and the circumference of the area.
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*/
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void RS_InfoArea::calculate() {
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area = 0.0;
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circumference = 0.0;
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if(thePoints.size()<3) return;
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RS_Vector p1=thePoints.front();
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for(size_t i=0;i<thePoints.size();++i){
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// std::cout<<"RS_InfoArea::calculate(): "<<i<<" , "<<p1<<std::endl;
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RS_Vector p2=thePoints.at( (i+1)%thePoints.size());
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area += calcSubArea(p1, p2);
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circumference += p1.distanceTo(p2);
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p1=p2;
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}
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area = 0.5*fabs(area);
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calculationNeeded=false;
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}
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double RS_InfoArea::getArea(const QPolygon& polygon)
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{
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double ret= 0.0;
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if(polygon.size()<3) return ret;
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for(int i=0;i<polygon.size(); ++i){
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const QPoint& p0=polygon.at(i);
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const QPoint& p1=polygon.at((i+1)%polygon.size());
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ret += p0.x()*p1.y()-p0.y()*p1.x();
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}
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return 0.5*fabs(ret);
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}
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/**
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* Calculates a sub area.
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*
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* @param p1 first point
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* @param p2 second point
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*/
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double RS_InfoArea::calcSubArea(const RS_Vector& p1, const RS_Vector& p2) {
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double width = p2.x - p1.x;
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double height = (p1.y - baseY) + (p2.y - baseY);
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return width * height ; //moved a factor of 0.5 to calculate()
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}
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double RS_InfoArea::getArea() const{
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return area;
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}
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double RS_InfoArea::getCircumference() {
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if(calculationNeeded) calculate();
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return circumference;
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}
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int RS_InfoArea::size() {
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if(calculationNeeded) calculate();
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return thePoints.size();
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}
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const RS_Vector& RS_InfoArea::at(int i) const{
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return thePoints.at(i);
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}
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// EOF
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