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arclengthfunction.cpp
00001 /*************************************************************************** 00002 arclengthfunction.cpp - description 00003 ------------------- 00004 begin : Mon Nov 11 2002 00005 copyright : (C) 2002 by Fungmeista 00006 email : mizunoami44@users.sourceforge.net 00007 ***************************************************************************/ 00008 00009 /*************************************************************************** 00010 * * 00011 * This program is free software; you can redistribute it and/or modify * 00012 * it under the terms of the GNU General Public License as published by * 00013 * the Free Software Foundation; either version 2 of the License, or * 00014 * (at your option) any later version. * 00015 * * 00016 ***************************************************************************/ 00017 00018 #include "arclengthfunction.h" 00019 00020 #include <cmath> 00021 00022 #include <qpointarray.h> 00023 #include <qpainter.h> 00024 #include <qobject.h> 00025 00026 #include "fungmath.h" 00027 #include "fungparser.h" 00028 00029 ArcLengthFunction::ArcLengthFunction(BasicGraph *graph, int expressions) : MathFunction(graph,expressions) 00030 { 00031 pointsStorage = new QPointArray(); 00032 } 00033 ArcLengthFunction::~ArcLengthFunction() 00034 { 00035 delete pointsStorage; 00036 } 00037 00038 void ArcLengthFunction::calculate_and_draw(QPainter *painter) 00039 { 00040 if ( expression2 ) /* parametric graph */ 00041 { 00042 if ( arg1 > arg2 ) //bounds check 00043 { 00044 QString s( QObject::tr("Invalid bounds") ); 00045 setResult( s ); 00046 return; 00047 } 00048 00049 double step = 0.1; 00050 qDebug("arg1: %f, arg2: %f",arg1,arg2); 00051 pointsStorage->resize( static_cast<int>(ROUND((arg2-arg1)/step) + 2) ); 00052 double distance = 0; 00053 int i = 0; 00054 for (double t=arg1; t<arg2; t+=step) 00055 { 00056 double alpha[] = {t,animatorValue()}; 00057 double alpha2[] = {t+step,animatorValue()}; 00058 00059 double valuex = expression->Eval(alpha); 00060 double valuex2 = expression->Eval(alpha2); 00061 00062 double valuey = expression2->Eval(alpha); 00063 double valuey2 = expression2->Eval(alpha2); 00064 00065 (*pointsStorage)[i]=QPoint(toPixelXCoord(valuex),toPixelYCoord(valuey)); 00066 (*pointsStorage)[i+1]=QPoint(toPixelXCoord(valuex2),toPixelYCoord(valuey2)); 00067 00068 distance += sqrt( 00069 ((valuex-valuex2)*(valuex-valuex2))+ 00070 ((valuey-valuey2)*(valuey-valuey2)) 00071 ); 00072 00073 painter->drawLine(toPixelXCoord(valuex),toPixelYCoord(valuey),toPixelXCoord(valuex2),toPixelYCoord(valuey2)); 00074 00075 i++; 00076 } 00077 QString s = QString("Arc Length = %1").arg(distance); 00078 setResult(s); 00079 } 00080 else 00081 { 00082 if ( lowerBounds.x() > upperBounds.x() ) //bounds check 00083 { 00084 QString s( QObject::tr("Invalid bounds") ); 00085 setResult( s ); 00086 return; 00087 } 00088 00089 pointsStorage->resize(upperBounds.x()-lowerBounds.x() + 1); 00090 double distance = 0; 00091 for (int i=lowerBounds.x(); i<upperBounds.x(); i++) 00092 { 00093 double alpha[] = {toGraphXCoord(i),animatorValue()}; 00094 double alpha2[] = {toGraphXCoord(i+1),animatorValue()}; 00095 00096 double value = expression->Eval(alpha); 00097 double value2 = expression->Eval(alpha2); 00098 00099 (*pointsStorage)[i-lowerBounds.x()]=QPoint(i,toPixelYCoord(value)); 00100 (*pointsStorage)[i+1-lowerBounds.x()]=QPoint(i+1,toPixelYCoord(value2)); 00101 00102 distance += sqrt( 00103 ((alpha[0]-alpha2[0])*(alpha[0]-alpha2[0]))+ 00104 ((value-value2)*(value-value2)) 00105 ); 00106 00107 painter->drawLine(i,toPixelYCoord(value),i+1,toPixelYCoord(value2)); 00108 } 00109 QString s = QString("Arc Length = %1").arg(distance); 00110 setResult(s); 00111 } 00112 } 00113 00114 void ArcLengthFunction::draw_stored(QPainter *painter) 00115 { 00116 painter->drawPolyline(*pointsStorage); 00117 } 00118 00119