(C++) QtSurfacePlotWidget

January 25, 2018 · View on GitHub

 

 

 

 

 

(C++) QtSurfacePlotWidget

 

QtQt CreatorLubuntu

 

QtSurfacePlotWidget is a Qt class for displaying a surface plot.

Technical facts

 

 

 

 

 

 

./CppQtSurfacePlotWidget/CppQtSurfacePlotWidget.pri

 

INCLUDEPATH += \     ../../Classes/CppQtSurfacePlotWidget SOURCES += \     ../../Classes/CppQtSurfacePlotWidget/qtsurfaceplotwidget.cpp HEADERS  += \     ../../Classes/CppQtSurfacePlotWidget/qtsurfaceplotwidget.h OTHER_FILES += \     ../../Classes/CppQtSurfacePlotWidget/Licence.txt

 

 

 

 

 

./CppQtSurfacePlotWidget/qtsurfaceplotwidget.h

 

 

 

 

 

 

./CppQtSurfacePlotWidget/qtsurfaceplotwidget.cpp

 

//--------------------------------------------------------------------------- /* QtSurfacePlotWidget, Qt widget for displaying a surface plot Copyright 2012-2015 Richel Bilderbeek This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. 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, see <http://www.gnu.org/licenses/>. */ //--------------------------------------------------------------------------- //From http://www.richelbilderbeek.nl/CppQtSurfacePlotWidget.htm //--------------------------------------------------------------------------- #include <algorithm> #include <cassert> #include <vector> #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Weffc++" #pragma GCC diagnostic ignored "-Wunused-local-typedefs" #pragma GCC diagnostic ignored "-Wunused-but-set-parameter" #include <QPainter> #include "testtimer.h" #include "qtsurfaceplotwidget.h" #include "trace.h" #pragma GCC diagnostic pop ribi::QtSurfacePlotWidget::QtSurfacePlotWidget(QWidget *parent)   : QWidget(parent),     m_surface{} {   #ifndef NDEBUG   Test();   #endif   std::vector<std::vector<unsigned char>> v(128,std::vector<unsigned char>(128));   for(int y=0; y!=128; ++y)   {     for (int x=0; x!=128; ++x)     {       v[y][x] = x + y;     }   }   SetSurfaceGrey(v); } std::string ribi::QtSurfacePlotWidget::GetVersion() {   return "1.1"; } std::vector<std::string> ribi::QtSurfacePlotWidget::GetVersionHistory() {   return {     "2012-07-14: version 1.0: initial version",     "2014-07-08: version 1.1: added use of Function functor"   }; } void ribi::QtSurfacePlotWidget::paintEvent(QPaintEvent *) {   QPainter painter(this);   assert(!m_surface.empty());   const int maxy = m_surface.size();   assert(maxy > 0);   const int maxx = m_surface[0].size();   assert(maxx > 0);   QImage image (maxx,maxy,QImage::Format::Format_RGB32);   for (int y=0; y!=maxy; ++y)   {     std::vector<unsigned char>& line = m_surface[y];     for (int x=0; x!=maxx; ++x)     {       assert(x < static_cast<int>(line.size()));       const unsigned char grey = line[x];       image.setPixel(x,y,qRgb(grey,grey,grey));     }   }   painter.drawPixmap(0,0,this->width(),this->height(),QPixmap::fromImage(image)); } void ribi::QtSurfacePlotWidget::Plot(   const Function& f,   const double x_min, const double x_max,   const double y_min, const double y_max ) noexcept {   assert(x_min < x_max);   assert(y_min < y_max);   //Evaluate the function in a 2D std::vector   const int n_rows = height();   const int n_cols = width();   std::vector<std::vector<double>> v(n_rows,std::vector<double>(n_cols,0.0));   const double n_rows_d = static_cast<double>(n_rows);   const double n_cols_d = static_cast<double>(n_cols);   for (int y = 0; y!=n_rows; ++y)   {     const double yD = static_cast<double>(y);     const double y_scaled = Rescale(yD,0.0,n_rows_d,y_min,y_max);     for (int x = 0; x!=n_cols; ++x)     {       const double xD = static_cast<double>(x);       const double x_scaled = Rescale(xD,0.0,n_cols_d,x_min,x_max);       const double z = f(x_scaled,y_scaled);       v[y][x] = z;     }   }   //Plot the 2D std::vector   SetSurfaceGrey(v); } double ribi::QtSurfacePlotWidget::Rescale(   const double value,   const double old_min,   const double old_max,   const double new_min,   const double new_max) noexcept {   assert(value >= old_min);   assert(value <= old_max);   const double old_distance = old_max - old_min;   //At which relative distance is value on old_min to old_max ?   const double distance = (value - old_min) / old_distance;   assert(distance >= 0.0);   assert(distance <= 1.0);   const double new_distance = new_max - new_min;   const double new_value = new_min + (distance * new_distance);   assert(new_value >= new_min);   assert(new_value <= new_max);   return new_value; } void ribi::QtSurfacePlotWidget::resizeEvent(QResizeEvent *) {   this->repaint(); } void ribi::QtSurfacePlotWidget::SetSurfaceGrey(const std::vector<std::vector<double>>& v) {   //Get the size   const int maxx = v[0].size();   const int maxy = v.size();   //Minimum and maximum are not given, so these need to be calculated   double min_val = *(std::min_element(v[0].begin(),v[0].end()));   double max_val = *(std::max_element(v[0].begin(),v[0].end()));   for (int y=1; y!=maxy; ++y) //1, because 0 gets know the lines above   {     const double local_min_val = *(std::min_element(v[y].begin(),v[y].end()));     const double local_max_val = *(std::max_element(v[y].begin(),v[y].end()));     if (local_min_val < min_val) min_val = local_min_val;     if (local_max_val > max_val) max_val = local_max_val;   }   //Create a black surface of type unsigned char   std::vector<std::vector<unsigned char>> w(maxy,std::vector<unsigned char>(maxx,0));   if (min_val == max_val)   {     //Keep black surface in w black   }   else   {     for (int y=0; y!=maxy; ++y)     {       const std::vector<double>& line_in = v[y];       std::vector<unsigned char>& line_out = w[y];       for (int x=0; x!=maxx; ++x)       {         assert(min_val != max_val);         assert(min_val < max_val);         assert(x < static_cast<int>(line_in.size()));         const double grey_double = (line_in[x] - min_val) / (max_val - min_val);         assert(grey_double >= 0.0 && grey_double <= 1.0);         const unsigned char grey = grey_double * 255.0;         assert(x < static_cast<int>(line_out.size()));         line_out[x] = grey;       }     }   }   SetSurfaceGrey(w); } void ribi::QtSurfacePlotWidget::SetSurfaceGrey(const std::vector<std::vector<unsigned char>>& surface) {   m_surface = surface;   this->repaint(); } #ifndef NDEBUG void ribi::QtSurfacePlotWidget::Test() noexcept {   {     static bool is_tested{false};     if (is_tested) return;     is_tested = true;   }   const TestTimer test_timer(__func__,__FILE__,1.0);   assert(Rescale(2.0,1.0,5.0,0.0,100.0) >= 24.9999 && Rescale(2.0,1.0,5.0,0.0,100.0) < 25.0001); } #endif