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densityplot.cpp
00001 /*************************************************************************** 00002 densityplot.cpp - description 00003 ------------------- 00004 begin : Sat Feb 15 2003 00005 copyright : (C) 2002-03 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 "densityplot.h" 00019 00020 #include <cmath> 00021 00022 #include <qpainter.h> 00023 00024 #include "fungparser.h" 00025 #include "expression.h" 00026 #include "fungmath.h" 00027 00028 DensityPlot::DensityPlot ( QWidget *parent, const char *name ) : ExpressionGraph( parent, name ) 00029 { 00030 onlyShowActive(true); 00031 } 00032 00033 DensityPlot::~DensityPlot() 00034 { 00035 } 00036 00037 void DensityPlot::drawExpression(QPainter *painter, Expression & expression) 00038 { 00039 FungParser *fp = expression.getParsedExpression(dependent_var()); 00040 00041 QColor color = painter->pen().color(); 00042 00043 double *values = new double[width()*height()]; 00044 int i = 0; 00045 double extreme = 0; 00046 00047 //we need to find the value of the expression with the greatest absolute value for calculating the color 00048 //... while looping through and getting values 00049 //they are saved to speed things up in the values[] array 00050 for (int x = 0; x < width(); x++) 00051 { 00052 for (int y = 0; y < height(); y++) 00053 { 00054 double d[] = {toGraphXCoord(x),toGraphYCoord(y),animatorValue()}; 00055 values[i] = fp->Eval(d); 00056 00057 if ( fabs(values[i]) >= fabs(extreme) ) 00058 extreme = values[i]; 00059 00060 i++; 00061 } 00062 } 00063 00064 double alpha = (extreme == 0) ? 0 : 255 / fabs(extreme*2); 00065 int h, s, v; color.getHsv( h, s, v ); 00066 i = 0; 00067 for (int x = 0; x < width(); x++) 00068 { 00069 for (int y = 0; y < height(); y++) 00070 { 00071 QColor c; 00072 c.setHsv( h, s, int(ROUND(255/2 + values[i] * alpha )) ); 00073 00074 painter->setPen( c ); 00075 painter->drawPoint(x,y); 00076 00077 i++; 00078 } 00079 } 00080 00081 delete[] values; 00082 } 00083 00084 int DensityPlot::setXYForTrace(const double mousex, const double mousey, double *x, double *y, Expression &) 00085 { 00086 *x = mousex; 00087 *y = mousey; 00088 00089 return 0; 00090 } 00091 00092 void DensityPlot::updateCoords() 00093 { 00094 if (isTracing()) 00095 { 00096 FungParser *fp = getParsedCurrentExpression(); 00097 double d[] = {getMouseX(),getMouseY(),animatorValue()}; 00098 double z = fp->Eval(d); 00099 00100 emit activeCoordinateChanged( QString("x = %1").arg(getMouseX()), 00101 QString("y = %1").arg(getMouseY()), 00102 QString("z = %1").arg(z) ); 00103 } 00104 else 00105 BasicGraph::updateCoords(); 00106 } 00107