#ifndef MAINWINDOW_H#define MAINWINDOW_H#include #define PI 3.1415926QT_BEGIN_NAMESPACEnamespace Ui { class MainWindow; }QT_END_NAMESPACEclass MainWindow : public QMainWindow{    Q_OBJECTpublic:    MainWindow(QWidget *parent = nullptr);    ~MainWindow();    // QObject interfaceprotected:    void timerEvent(QTimerEvent *event);    // QWidget interfaceprotected:    void paintEvent(QPaintEvent *event);private:    int m_nSize = 10;    float m_nT = 0;};#endif // MAINWINDOW_H

#include #include #include #include "mainwindow.h"MainWindow::MainWindow(QWidget *parent)    : QMainWindow(parent){    resize(600, 600);    startTimer(200);}MainWindow::~MainWindow(){}void MainWindow::timerEvent(QTimerEvent *event){    if (m_nT > 500)    {        m_nT = 0;    }    if (m_nSize == 5)    {        m_nSize = 10;    }    m_nSize--;    m_nT += 1;    update();}void MainWindow::paintEvent(QPaintEvent *event){    QPainter painter(this);    painter.setRenderHint(QPainter::Antialiasing);    painter.translate(this->width() / 2.0, this->height() / 2.0);    painter.setPen(Qt::red);    painter.setBrush(Qt::red);    double t = 0;    double vt = 0.01;    double maxT = 2 * PI;    int maxC = ceil(maxT / vt);    QPainterPath path;    double x = 0;    double y = 0;    QPointF pt(x, y);    path.moveTo(pt);    for (int i = 0; i < maxC; ++i)    {        x = 16 * pow(sin(t) ,3);        y = 13 * cos(t) - 5 * cos(2 * t) - 2 * cos(3 * t) - cos(4 * t);        pt.setX(x * m_nSize);        pt.setY(-y * m_nSize);        t += vt;        path.lineTo(pt);    }    painter.drawPath(path);}