diff -r aee36896d46b -r e7882bd1a894 QTfrontend/drawmapscene.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/QTfrontend/drawmapscene.cpp	Mon Dec 13 22:12:30 2010 +0300
@@ -0,0 +1,178 @@
+#include <QGraphicsSceneMouseEvent>
+#include <QGraphicsPathItem>
+#include <QtEndian>
+
+#include "drawmapscene.h"
+
+template <class T> T sqr(const T & x)
+{
+    return x*x;
+}
+
+DrawMapScene::DrawMapScene(QObject *parent) :
+    QGraphicsScene(parent),
+    m_pen(Qt::yellow),
+    m_brush(Qt::yellow)
+{
+    setSceneRect(0, 0, 4096, 2048);
+
+    QLinearGradient gradient(0, 0, 0, 2048);
+    gradient.setColorAt(0, QColor(60, 60, 155));
+    gradient.setColorAt(1, QColor(155, 155, 60));
+    setBackgroundBrush(QBrush(gradient));
+
+    m_pen.setWidth(67);
+    m_pen.setJoinStyle(Qt::RoundJoin);
+    m_pen.setCapStyle(Qt::RoundCap);
+    m_currPath = 0;
+}
+
+void DrawMapScene::mouseMoveEvent(QGraphicsSceneMouseEvent * mouseEvent)
+{
+    if(m_currPath && (mouseEvent->buttons() & Qt::LeftButton))
+    {
+        QPainterPath path = m_currPath->path();
+        path.lineTo(mouseEvent->scenePos());
+        paths.first().append(mouseEvent->scenePos().toPoint());
+        m_currPath->setPath(path);
+
+        emit pathChanged();
+    }
+}
+
+void DrawMapScene::mousePressEvent(QGraphicsSceneMouseEvent * mouseEvent)
+{
+    m_currPath = addPath(QPainterPath(), m_pen);
+
+    QPainterPath path = m_currPath->path();
+    QPointF p = mouseEvent->scenePos();
+    p += QPointF(0.01, 0.01);
+    path.moveTo(p);
+    path.lineTo(mouseEvent->scenePos());
+    paths.prepend(QList<QPoint>() << mouseEvent->scenePos().toPoint());
+    m_currPath->setPath(path);
+
+    emit pathChanged();
+}
+
+void DrawMapScene::mouseReleaseEvent(QGraphicsSceneMouseEvent * mouseEvent)
+{
+    simplifyLast();
+
+    m_currPath = 0;
+}
+
+void DrawMapScene::undo()
+{
+    if(items().size())
+    {
+        removeItem(items().first());
+        paths.removeFirst();
+
+        emit pathChanged();
+    }
+}
+
+QByteArray DrawMapScene::encode()
+{
+    QByteArray b;
+
+    foreach(QList<QPoint> points, paths)
+    {
+        int cnt = 0;
+        foreach(QPoint point, points)
+        {
+            qint16 px = qToBigEndian((qint16)point.x());
+            qint16 py = qToBigEndian((qint16)point.y());
+            quint8 flags = 2;
+            if(!cnt) flags |= 0x80;
+            b.append((const char *)&px, 2);
+            b.append((const char *)&py, 2);
+            b.append((const char *)&flags, 1);
+
+            ++cnt;
+        }
+
+    }
+
+    return b;
+}
+
+void DrawMapScene::decode(QByteArray data)
+{
+    clear();
+    paths.clear();
+
+    QList<QPoint> points;
+
+    while(data.size() >= 5)
+    {
+        qint16 px = qFromBigEndian(*(qint16 *)data.data());
+        data.remove(0, 2);
+        qint16 py = qFromBigEndian(*(qint16 *)data.data());
+        data.remove(0, 2);
+        quint8 flags = *(quint8 *)data.data();
+        data.remove(0, 1);
+
+        //last chunk or first point
+        if((data.size() < 5) || (flags & 0x80))
+        {
+            if(points.size())
+            {
+                addPath(pointsToPath(points), m_pen);
+                paths.prepend(points);
+
+                points.clear();
+            }
+        }
+
+        points.append(QPoint(px, py));
+    }
+}
+
+void DrawMapScene::simplifyLast()
+{
+    QList<QPoint> points = paths[0];
+
+    QPoint prevPoint = points.first();
+    int i = 1;
+    while(i < points.size())
+    {
+        if( (i != points.size() - 1)
+            && (sqr(prevPoint.x() - points[i].x()) + sqr(prevPoint.y() - points[i].y()) < 1000)
+          )
+            points.removeAt(i);
+        else
+        {
+            prevPoint = points[i];
+            ++i;
+        }
+    }
+
+    paths[0] = points;
+
+
+    // redraw path
+    {
+        QGraphicsPathItem * pathItem = static_cast<QGraphicsPathItem *>(items()[0]);
+        pathItem->setPath(pointsToPath(paths[0]));
+    }
+
+    emit pathChanged();
+}
+
+QPainterPath DrawMapScene::pointsToPath(const QList<QPoint> points)
+{
+    QPainterPath path;
+
+    if(points.size())
+    {
+        QPointF p = points[0] + QPointF(0.01, 0.01);
+        path.moveTo(p);
+
+        foreach(QPoint p, points)
+            path.lineTo(p);
+    }
+
+    return path;
+}