Qt 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);
                 }
             }
         }
     }