(C++) DrawGlobeQt

February 24, 2017 · View on GitHub

 

 

 

 

 

(C++) DrawGlobeQt

 

Qt Creator project to demonstrate DrawGlobe source code.

 

 

Operating system: Ubuntu 10.04 LTS Lucid Lynx

IDE: Qt Creator 2.0.0

Project type: GUI application

Compiler: G++ 4.4.1

Libraries used:

 

 

 

 

 

Qt project file

 

#------------------------------------------------- # # Project created by QtCreator 2010-08-13T11:59:16 # #------------------------------------------------- QT += core gui TARGET = CppDrawGlobe TEMPLATE = app SOURCES += main.cpp\ dialog.cpp HEADERS += dialog.h FORMS += dialog.ui RESOURCES += \ resources.qrc

 

 

 

 

 

dialog.cpp

 

#include <iostream> #include <boost/lexical_cast.hpp> #include <boost/numeric/conversion/cast.hpp> #include <QDesktopWidget> #include "dialog.h" #include "ui_dialog.h" Dialog::Dialog(QWidget *parent) :     QDialog(parent, Qt::Window),     ui(new Ui::Dialog) {   ui->setupUi(this);   QObject::connect(ui->dial_r,SIGNAL(valueChanged(int)),this,SLOT(onAnyChange()));   QObject::connect(ui->dial_g,SIGNAL(valueChanged(int)),this,SLOT(onAnyChange()));   QObject::connect(ui->dial_b,SIGNAL(valueChanged(int)),this,SLOT(onAnyChange()));   //Put the dialog in the screen center   const QRect screen = QApplication::desktop()->screenGeometry();   this->move( screen.center() - this->rect().center() ); } Dialog::~Dialog() {   delete ui; } void Dialog::changeEvent(QEvent *e) {   QDialog::changeEvent(e);   switch (e->type()) {   case QEvent::LanguageChange:     ui->retranslateUi(this);     break;   default:     break;   } } void Dialog::onAnyChange() {   ui->label_r->setText("Red: "     + QString(boost::lexical_cast<std::string>(ui->dial_r->sliderPosition()).c_str()));   ui->label_g->setText("Green: "     + QString(boost::lexical_cast<std::string>(ui->dial_g->sliderPosition()).c_str()));   ui->label_b->setText("Blue: "     + QString(boost::lexical_cast<std::string>(ui->dial_b->sliderPosition()).c_str()));   ui->label->setPixmap(     DrawGlobe(       ui->label->width(),       ui->label->height(),       ui->dial_r->sliderPosition(),       ui->dial_g->sliderPosition(),       ui->dial_b->sliderPosition())); } void Dialog::resizeEvent(QResizeEvent*) {   this->onAnyChange(); } //From http://www.richelbilderbeek.nl/CppDrawGlobe.htm QPixmap DrawGlobe(   const int width,   const int height,   const unsigned char r,   const unsigned char g,   const unsigned char b) {   QPixmap pixmap(width,height);   QImage image = pixmap.toImage();   assert(image.bytesPerLine() / width == 4     && "Assume there are 4 bytes per pixel");   const double r_max = boost::numeric_cast<double>(r);   const double g_max = boost::numeric_cast<double>(g);   const double b_max = boost::numeric_cast<double>(b);   const double midX = boost::numeric_cast<double>(width ) / 2.0;   const double midY = boost::numeric_cast<double>(height) / 2.0;   const double max_dist = std::min(midX,midY);   for (int y=0; y!=height; ++y)   {     unsigned char * const line       = static_cast<unsigned char *>(image.scanLine(y));     const double y_d = boost::numeric_cast<double>(y);     for (int x=0; x!=width; ++x)     {       const double x_d = boost::numeric_cast<double>(x);       const double dist         = std::sqrt(             ((x_d - midX) * (x_d - midX))           + ((y_d - midY) * (y_d - midY)) );       if (dist <= max_dist)       {         const double rel_dist = dist / max_dist;         const int r_here = rel_dist * r_max;         const int g_here = rel_dist * g_max;         const int b_here = rel_dist * b_max;         assert( r_here >= 0);         assert( r_here < 256);         assert( g_here >= 0);         assert( g_here < 256);         assert( b_here >= 0);         assert( b_here < 256);         line[x*4+3] = 255; //Alpha value         //New color values are 1 at least         line[x*4+2] = (r_here == 0 ? 1 : r_here); //Red         line[x*4+1] = (g_here == 0 ? 1 : g_here); //Green         line[x*4+0] = (b_here == 0 ? 1 : b_here); //Blue       }       else       {         line[x*4+3] = 0; //Alpha value         line[x*4+2] = 0; //Red         line[x*4+1] = 0; //Green         line[x*4+0] = 0; //Blue       }     }   }   pixmap = pixmap.fromImage(image);   //Add transparency   const QBitmap mask = pixmap.createMaskFromColor(QColor(0,0,0,0).rgb());   pixmap.setMask(mask);   return pixmap; }

 

 

 

 

 

dialog.h

 

#ifndef DIALOG_H #define DIALOG_H #include <boost/shared_ptr.hpp> #include <QDialog> namespace Ui {   class Dialog; } class Dialog : public QDialog {   Q_OBJECT public:   explicit Dialog(QWidget *parent = 0);   ~Dialog(); protected:   void changeEvent(QEvent *e); private:   Ui::Dialog *ui;   void resizeEvent(QResizeEvent*); private slots:   void onAnyChange(); }; #endif // DIALOG_H //From http://www.richelbilderbeek.nl/CppDrawGlobe.htm QPixmap DrawGlobe(   const int width,   const int height,   const unsigned char r,   const unsigned char g,   const unsigned char b);

 

 

 

 

 

main.cpp

 

#include <QtGui/QApplication> #include "dialog.h" int main(int argc, char *argv[]) {     QApplication a(argc, argv);     Dialog w;     w.show();     return a.exec(); }