- Qt 5.5
- Qt Widgets
- Stickman Example
- stickman.cpp Example File
- Qt 5.5.1 Reference Documentation

# stickman.cpp Example File

animation/stickman/stickman.cpp

    /****************************************************************************
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    #include "stickman.h"
    #include "node.h"

    #include <QPainter>
    #include <QTimer>

    #define _USE_MATH_DEFINES
    #include <math.h>

    #ifndef M_PI
    #define M_PI 3.14159265358979323846
    #endif

    static const qreal Coords[NodeCount * 2] = {
        0.0, -150.0, // head, #0

        0.0, -100.0, // body pentagon, top->bottom, left->right, #1 - 5
        -50.0, -50.0,
        50.0, -50.0,
        -25.0, 50.0,
        25.0, 50.0,

        -100.0, 0.0, // right arm, #6 - 7
        -125.0, 50.0,

        100.0, 0.0, // left arm, #8 - 9
        125.0, 50.0,

        -35.0, 75.0, // lower body, #10 - 11
        35.0, 75.0,

        -25.0, 200.0, // right leg, #12 - 13
        -30.0, 300.0,

        25.0, 200.0, // left leg, #14 - 15
        30.0, 300.0

    };

    static const int Bones[BoneCount * 2] = {
        0, 1, // neck

        1, 2, // body
        1, 3,
        1, 4,
        1, 5,
        2, 3,
        2, 4,
        2, 5,
        3, 4,
        3, 5,
        4, 5,

        2, 6, // right arm
        6, 7,

        3, 8, // left arm
        8, 9,

        4, 10, // lower body
        4, 11,
        5, 10,
        5, 11,
        10, 11,

        10, 12, // right leg
        12, 13,

        11, 14, // left leg
        14, 15

    };

    StickMan::StickMan()
    {
        m_sticks = true;
        m_isDead = false;
        m_pixmap = QPixmap("images/head.png");
        m_penColor = Qt::white;
        m_fillColor = Qt::black;

        // Set up start position of limbs
        for (int i=0; i<NodeCount; ++i) {
            m_nodes[i] = new Node(QPointF(Coords[i * 2], Coords[i * 2 + 1]), this);
            connect(m_nodes[i], SIGNAL(positionChanged()), this, SLOT(childPositionChanged()));
        }

        for (int i=0; i<BoneCount; ++i) {
            int n1 = Bones[i * 2];
            int n2 = Bones[i * 2 + 1];

            Node *node1 = m_nodes[n1];
            Node *node2 = m_nodes[n2];

            QPointF dist = node1->pos() - node2->pos();
            m_perfectBoneLengths[i] = sqrt(pow(dist.x(),2) + pow(dist.y(),2));
        }

        startTimer(10);
    }

    StickMan::~StickMan()
    {
    }

    void StickMan::childPositionChanged()
    {
        prepareGeometryChange();
    }

    void StickMan::setDrawSticks(bool on)
    {
        m_sticks = on;
        for (int i=0;i<nodeCount();++i) {
            Node *node = m_nodes[i];
            node->setVisible(on);
        }
    }

    QRectF StickMan::boundingRect() const
    {
        // account for head radius=50.0 plus pen which is 5.0
        return childrenBoundingRect().adjusted(-55.0, -55.0, 55.0, 55.0);
    }

    int StickMan::nodeCount() const
    {
        return NodeCount;
    }

    Node *StickMan::node(int idx) const
    {
        if (idx >= 0 && idx < NodeCount)
            return m_nodes[idx];
        else
            return 0;
    }

    void StickMan::timerEvent(QTimerEvent *)
    {
        update();
    }

    void StickMan::stabilize()
    {
        static const qreal threshold = 0.001;

        for (int i=0; i<BoneCount; ++i) {
            int n1 = Bones[i * 2];
            int n2 = Bones[i * 2 + 1];

            Node *node1 = m_nodes[n1];
            Node *node2 = m_nodes[n2];

            QPointF pos1 = node1->pos();
            QPointF pos2 = node2->pos();

            QPointF dist = pos1 - pos2;
            qreal length = sqrt(pow(dist.x(),2) + pow(dist.y(),2));
            qreal diff = (length - m_perfectBoneLengths[i]) / length;

            QPointF p = dist * (0.5 * diff);
            if (p.x() > threshold && p.y() > threshold) {
                pos1 -= p;
                pos2 += p;

                node1->setPos(pos1);
                node2->setPos(pos2);
            }
        }
    }

    QPointF StickMan::posFor(int idx) const
    {
        return m_nodes[idx]->pos();
    }

    //#include <QTime>
    void StickMan::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
    {
      /*  static int frames = 0;
        static QTime time;
        if (frames++ % 100 == 0) {
            frames = 1;
            time.restart();
        }

        if (time.elapsed() > 0) {
            painter->setPen(Qt::white);
            painter->drawText(0, 0, QString::number(frames / (time.elapsed() / 1000.0)));
        }*/

        stabilize();
        if (m_sticks) {
            painter->setPen(Qt::white);
            for (int i=0; i<BoneCount; ++i) {
                int n1 = Bones[i * 2];
                int n2 = Bones[i * 2 + 1];

                Node *node1 = m_nodes[n1];
                Node *node2 = m_nodes[n2];

                painter->drawLine(node1->pos(), node2->pos());
            }
        } else {
            // first bone is neck and will be used for head

            QPainterPath path;
            path.moveTo(posFor(0));
            path.lineTo(posFor(1));

            // right arm
            path.lineTo(posFor(2));
            path.lineTo(posFor(6));
            path.lineTo(posFor(7));

            // left arm
            path.moveTo(posFor(3));
            path.lineTo(posFor(8));
            path.lineTo(posFor(9));

            // body
            path.moveTo(posFor(2));
            path.lineTo(posFor(4));
            path.lineTo(posFor(10));
            path.lineTo(posFor(11));
            path.lineTo(posFor(5));
            path.lineTo(posFor(3));
            path.lineTo(posFor(1));

            // right leg
            path.moveTo(posFor(10));
            path.lineTo(posFor(12));
            path.lineTo(posFor(13));

            // left leg
            path.moveTo(posFor(11));
            path.lineTo(posFor(14));
            path.lineTo(posFor(15));

            painter->setPen(QPen(m_penColor, 5.0, Qt::SolidLine, Qt::RoundCap));
            painter->drawPath(path);

            {
                int n1 = Bones[0];
                int n2 = Bones[1];
                Node *node1 = m_nodes[n1];
                Node *node2 = m_nodes[n2];

                QPointF dist = node2->pos() - node1->pos();

                qreal sinAngle = dist.x() / sqrt(pow(dist.x(), 2) + pow(dist.y(), 2));
                qreal angle = asin(sinAngle) * 180.0 / M_PI;

                QPointF headPos = node1->pos();
                painter->translate(headPos);
                painter->rotate(-angle);

                painter->setBrush(m_fillColor);
                painter->drawEllipse(QPointF(0,0), 50.0, 50.0);

                painter->setBrush(m_penColor);
                painter->setPen(QPen(m_penColor, 2.5, Qt::SolidLine, Qt::RoundCap));

                // eyes
                if (m_isDead) {
                    painter->drawLine(-30.0, -30.0, -20.0, -20.0);
                    painter->drawLine(-20.0, -30.0, -30.0, -20.0);

                    painter->drawLine(20.0, -30.0, 30.0, -20.0);
                    painter->drawLine(30.0, -30.0, 20.0, -20.0);
                } else {
                    painter->drawChord(QRectF(-30.0, -30.0, 25.0, 70.0), 30.0*16, 120.0*16);
                    painter->drawChord(QRectF(5.0, -30.0, 25.0, 70.0), 30.0*16, 120.0*16);
                }

                // mouth
                if (m_isDead) {
                    painter->drawLine(-28.0, 2.0, 29.0, 2.0);
                } else {
                    painter->setBrush(QColor(128, 0, 64 ));
                    painter->drawChord(QRectF(-28.0, 2.0-55.0/2.0, 57.0, 55.0), 0.0, -180.0*16);
                }

                // pupils
                if (!m_isDead) {
                    painter->setPen(QPen(m_fillColor, 1.0, Qt::SolidLine, Qt::RoundCap));
                    painter->setBrush(m_fillColor);
                    painter->drawEllipse(QPointF(-12.0, -25.0), 5.0, 5.0);
                    painter->drawEllipse(QPointF(22.0, -25.0), 5.0, 5.0);
                }
            }
        }
    }