src/robomon/trail.cpp

   1 #include "trail.h"
   2 #include <QPainter>
   3 #include "PlaygroundScene.h"
   4
   5 Trail::Trail(const QPen &pen): QGraphicsItem(), bound(-1,-1,0,0)
   6 {
   7         this->pen = pen;
   8         reset();
   9 }
  10
  11
  12 Trail::~Trail()
  13 {
  14 }
  15
  16 QRectF Trail::boundingRect() const
  17 {
  18         return bound;
  19 }
  20
  21 void Trail::findBound()
  22 {
  23         prepareGeometryChange();
  24         bound.setCoords(9999, -1, -1, 9999);
  25         for (unsigned i = 0; i<trailLen; i++) {
  26                 if (points[i].x() < 0 || points[i].y() < 0)
  27                         continue;
  28                 if (points[i].x() < bound.left()) {
  29                         bound.setLeft(points[i].x());
  30                 }
  31                 if (points[i].x() > bound.right()) {
  32                         bound.setRight(points[i].x());
  33                 }
  34                 if (points[i].y() < bound.bottom()) {
  35                         bound.setBottom(points[i].y());
  36                 }
  37                 if (points[i].y() > bound.top()) {
  38                         bound.setTop(points[i].y());
  39                 }
  40         }
  41 }
  42
  43 void Trail::addPoint(QPointF point)
  44 {
  45         prepareGeometryChange();
  46         point = PlaygroundScene::world2scene(point);
  47
  48         currentIndex = (currentIndex+1) % trailLen;
  49         if (points[currentIndex].x() >= 0) {
  50                 //overwrite old point
  51                 update(QRectF( points[currentIndex],
  52                                points[(currentIndex+1)%trailLen]));
  53         }
  54
  55         points[currentIndex] = point;
  56         findBound();
  57
  58         if (point.x() < bound.left()) {
  59                 bound.setLeft(point.x());
  60         }
  61         if (point.x() > bound.right()) {
  62                 bound.setRight(point.x());
  63         }
  64         if (point.y() < bound.bottom()) {
  65                 bound.setBottom(point.y());
  66         }
  67         if (point.y() > bound.top()) {
  68                 bound.setTop(point.y());
  69         }
  70
  71         update(QRectF( points[(currentIndex+trailLen-1)%trailLen],
  72                        points[currentIndex]));
  73 }
  74
  75 void Trail::paint(QPainter * painter, const QStyleOptionGraphicsItem * option, QWidget * widget)
  76 {
  77         if (currentIndex == (unsigned)-1)
  78                 return;
  79
  80         painter->setPen(pen);
  81
  82         painter->drawPolyline(points, currentIndex+1);
  83         if (currentIndex < trailLen - 2 && points[currentIndex+1].x() >= 0) {
  84                 painter->drawPolyline(&points[currentIndex+1], trailLen-currentIndex-1);
  85                 painter->drawLine(points[trailLen-1], points[0]);
  86         }
  87 }
  88
  89
  90
  91
  92 void Trail::reset()
  93 {
  94         currentIndex = -1;
  95         for (unsigned i=0; i<trailLen; i++)
  96                 points[i] = QPointF(-1, -1);
  97 }