我的挖掘机

非常感谢navca的分享。该例子基于QGraphicsItem绘图实现的挖掘机。(文末源码地址)

demo.gif

心中有坐标，万物皆可绘

  我的挖掘机例子共分为车体，大臂，小臂，爪子四部分，全部皆为自绘。

• 车体

void Body::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setBrush(QBrush(Qt::darkYellow));
    painter->drawRect(0,0,220,100);
    painter->drawRect(100,-80,100,80);

    painter->setBrush(QBrush(Qt::darkYellow));
    painter->drawEllipse(_pinPoint1, 5,5);
    painter->drawEllipse(_pinPoint2, 5,5);

    painter->setPen(QPen(QBrush(Qt::gray), 6));
    QPointF p(mapFromItem(_bigHand, _bigHand->PinPoint));
    painter->drawLine(_pinPoint2.x(), _pinPoint2.y(), p.x(), p.y());

    //液压臂
    painter->setPen(QPen(QBrush(Qt::black), 10));
    QLineF line(_pinPoint2, p);
    qreal angle = line.angle();
    QPointF midPoint(_pinPoint2.x()+ 80*cos(qDegreesToRadians(angle)), _pinPoint2.y() - 80*sin(qDegreesToRadians(angle)));
    painter->drawLine(_pinPoint2, midPoint);
}

• 大臂

void BigHand::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setPen(Qt::black);
    painter->setBrush(Qt::yellow);

    QPainterPath path;
    path.moveTo(-6,2);
    path.lineTo(60,-180);
    path.lineTo(250,-270);
    path.lineTo(258,-260);
    path.lineTo(90,-150);
    path.lineTo(5,5);

    path.moveTo(_pinPoint2.x()-10, _pinPoint2.y()+5);
    path.lineTo(_pinPoint2.x()-5, _pinPoint2.y()-8);
    path.lineTo(_pinPoint2.x()+8, _pinPoint2.y()-5);
    path.lineTo(_pinPoint2.x()-10, _pinPoint2.y()+5);
    painter->drawPath(path);

    painter->setBrush(Qt::darkYellow);
    painter->drawEllipse(-4,-5,10,10);
    painter->drawEllipse(PinPoint,5,5);

    painter->drawEllipse(_pinPoint1,5,5);

    painter->drawEllipse(_pinPoint2,5,5);

    painter->setPen(QPen(QBrush(Qt::gray), 6));
    QPointF p(mapFromItem(_smallHand, _smallHand->PinPoint));
    painter->drawLine(_pinPoint2.x(), _pinPoint2.y(), p.x(), p.y());

    //液压臂
    painter->setPen(QPen(QBrush(Qt::black), 10));
    QLineF line(_pinPoint2, p);
    qreal angle = line.angle();
    QPointF midPoint(_pinPoint2.x()+ 110*cos(qDegreesToRadians(angle)), _pinPoint2.y() - 110*sin(qDegreesToRadians(angle)));
    painter->drawLine(_pinPoint2, midPoint);
}

• 小臂

void SmallHand::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setPen(Qt::black);
    painter->setBrush(Qt::yellow);

    QPainterPath path;
    path.moveTo(-50, -30);
    path.lineTo(200, 0);
    path.lineTo(198, 10);
    path.lineTo(-3, 5);
    path.lineTo(-55, -18);
    path.lineTo(-50, -30);

    path.moveTo(_pinPoint1.x()-10, _pinPoint1.y()+5);
    path.lineTo(_pinPoint1.x(), _pinPoint1.y()-6);
    path.lineTo(_pinPoint1.x()+10, _pinPoint1.y()+7);
    path.lineTo(_pinPoint1.x()-8, _pinPoint1.y()+5);
    painter->drawPath(path);

    painter->setBrush(Qt::darkYellow);
    painter->drawEllipse(-5,-5, 10, 10);
    painter->drawEllipse(PinPoint,5,5);
    painter->drawEllipse(_pinPoint1,5,5);
    painter->drawEllipse(_pinPoint2,5,5);
    painter->drawEllipse(_pinPoint3,5,5);

    painter->setPen(QPen(QBrush(Qt::gray), 6));
    QPointF p(mapFromItem(_littleHand, _littleHand->PinPoint));
    painter->drawLine(_pinPoint1.x(), _pinPoint1.y(), p.x(), p.y());

    painter->setPen(QPen(QBrush(Qt::black), 10));
    QLineF line(_pinPoint1, p);
    qreal angle = line.angle();
    QPointF midPoint(_pinPoint1.x()+ 90*cos(qDegreesToRadians(angle)), _pinPoint1.y() - 90*sin(qDegreesToRadians(angle)));
    painter->drawLine(_pinPoint1, midPoint);

    painter->setPen(QPen(QBrush(Qt::black), 10));
    QPointF p1(mapFromItem(_hand, _hand->PinPoint));
    painter->drawLine(p.x(), p.y(), p1.x(), p1.y());
}

• 爪子

void Hand::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
    painter->setPen(Qt::black);
    painter->setBrush(Qt::yellow);

    QPainterPath path;
    path.moveTo(-12, -30);
    path.lineTo(-3, -35);
    path.lineTo(-6, -44);
    path.lineTo(6, -48);
    path.lineTo(35, -45);
    path.lineTo(70, 0);
    path.lineTo(15, -10);
    path.lineTo(10, 0);
    path.lineTo(3, 7);
    path.lineTo(-3, 3);
    path.lineTo(-12, -30);
    painter->drawPath(path);

    painter->setBrush(Qt::darkYellow);
    painter->drawEllipse(PinPoint,5,5);
    painter->drawEllipse(_pinPoint1,5,5);
}

main_page.png

源码地址(欢迎star)

• github地址：
  https://github.com/sunnyfulin/MyExcavator
• 码云地址：
  https://gitee.com/navca/MyExcavator