#include#include int main() { QPolygonF polygon({{1.0, 1.0}, {2.0, 2.0}, {3.0, 3.0}}); qDebug() << "Original polygon:" << polygon; polygon.clear(); qDebug() << "Cleared polygon:" << polygon; return 0; }
#includeIn this example, we create a polygon with three points, clear the polygon using the clear() method, add two new points using the << operator and the QPointF class, and print the coordinates again to confirm that the new points have been added. The QPolygonF class is part of the Qt GUI library, which is a package containing various classes and modules for building graphical user interfaces in C++.#include int main() { QPolygonF polygon({{1.0, 1.0}, {2.0, 2.0}, {3.0, 3.0}}); qDebug() << "Original polygon:" << polygon; polygon.clear(); qDebug() << "Cleared polygon:" << polygon; polygon << QPointF(4.0, 4.0) << QPointF(5.0, 5.0); qDebug() << "Modified polygon:" << polygon; return 0; }