最近在学习古老的QT开发手册,其中有一节是使用QT画图来实现正弦函数的小demo,稍微改变了一点,结果实现的结果超出了预期的想象,实现了3D的效果特此记录
//头文件
class drawDemo : public QWidget
{
Q_OBJECT
public:
explicit drawDemo(QWidget *parent = nullptr);
~drawDemo();
public slots:
void flushBuff();
protected:
virtual void paintEvent(QPaintEvent *);
private:
int buffer[200];
QTimer * timer;
const double PI = 3.1415926;
Ui::drawDemo *ui;
};
#endif // DRAWDEMO_H
//cpp
drawDemo::drawDemo(QWidget *parent) :
QWidget(parent),
ui(new Ui::drawDemo)
{
ui->setupUi(this);
this->setWindowTitle("test");
this->setStyleSheet("QWidget{background:#000000;}");
this->setGeometry(QRect(40,40,402,252));
for(int i = 0;i<200;i++)
{
buffer[i] = static_cast<int>((sin((i*PI)/100)*100));
}
timer = new QTimer();
connect(timer,&QTimer::timeout,this,&drawDemo::flushBuff);
timer->start(30);
}
drawDemo::~drawDemo()
{
delete ui;
}
void drawDemo::flushBuff()
{
int temp = buffer[0];
for(int i = 0;i<200;i++)
{
buffer[i]=buffer[i+1];
}
buffer[199]=temp;
update();
}
void drawDemo::paintEvent(QPaintEvent *)
{
QPainter painter(this);
QPoint beginPoint;
QPoint endPoint;
painter.setPen(Qt::blue);
for(int i = 0;i<199;i++)
{
beginPoint.setX(2*i);
beginPoint.setY(buffer[i]+125);
endPoint.setX(2*i+i);
endPoint.setY(buffer[i+1]+125);
painter.drawLine(beginPoint,endPoint);
}
}
实现结果: