winter.cpp

   1 #include "winter.h"
   2
   3 #include "misc.h"
   4
   5 #include <QDebug>
   6 #include <QGraphicsScene>
   7 #include <QGraphicsView>
   8 #include <QPen>
   9
  10 SnowFlake::SnowFlake(QGraphicsScene *scene)
  11 {
  12     size=qrand()%10+3;
  13
  14     int s4=size/4;
  15     int s3=size/3;
  16     int s6=size/6;
  17
  18     for (int a=0; a<6; a++)
  19     {
  20         lines.append(scene->addLine(0, -s6, 0, -size));
  21         lines.last()->setRotation(a*60);
  22
  23         lines.append(scene->addLine(-s4, -size + s6, 0, -size + s3));
  24         lines.last()->setRotation(a*60);
  25
  26         lines.append(scene->addLine( s4, -size + s6, 0, -size + s3));
  27         lines.last()->setRotation(a*60);
  28     }
  29
  30     QPen p(Qt::white);
  31     foreach (QGraphicsLineItem *l, lines)
  32     {
  33         l->setZValue(1000);
  34         l->setPen(p);
  35         l->setParentItem(this);
  36     }
  37     dv=QPointF(qrand()%10/10.0-0.5, qrand()%10/10.0 +1);
  38     da=qrand()%20 / 10.0 - 1;
  39 }
  40
  41 SnowFlake::~SnowFlake()
  42 {
  43     //qDebug()<<"Destr. SnowFlake";
  44     while(lines.isEmpty())
  45         delete lines.takeFirst();
  46 }
  47
  48 QRectF SnowFlake::boundingRect() const
  49 {
  50     return QRectF (-size, -size, size*2, size*2);
  51 }
  52
  53 void SnowFlake::paint(QPainter*, const QStyleOptionGraphicsItem*, QWidget*)
  54 {
  55 }
  56
  57 void SnowFlake::animate()
  58 {
  59     moveBy(dv.x() + dblow.x(), dv.y() + dblow.y());
  60     setRotation(rotation() + da);
  61     dblow = dblow *0.9;
  62 }
  63
  64 void SnowFlake::blow(const QPointF &v)
  65 {
  66     dblow=v;
  67 }
  68
  69 Winter::Winter(QGraphicsView *v)
  70 {
  71     view=v;
  72
  73     updateView();
  74     /*
  75     test=view->scene()->addLine(
  76             QLineF(viewRect.topLeft(), viewRect.bottomRight()),
  77             QPen(Qt::blue) );
  78     */
  79
  80     maxFlakes=1500;
  81     maxFalling=140;
  82     maxUnfreeze=50;
  83
  84     makeSnow();
  85
  86     animTimer = new QTimer;
  87     connect (animTimer, SIGNAL (timeout()), this, SLOT (animate() ));
  88     animTimer->start(50);
  89
  90     snowTimer = new QTimer;
  91     connect (snowTimer, SIGNAL (timeout()), this, SLOT (makeSnow() ));
  92     snowTimer->start(1000);
  93 }
  94
  95 Winter::~Winter()
  96 {
  97     delete animTimer;
  98     delete snowTimer;
  99     while (!fallingSnow.isEmpty())
 100         delete fallingSnow.takeFirst();
 101     while (!frozenSnow.isEmpty())
 102         delete frozenSnow.takeFirst();
 103 }
 104
 105 void Winter::updateView()
 106 {
 107     QPointF p0=view->mapToScene( QPoint(0,0));
 108     QPointF p1=view->mapToScene( view->rect().width(), view->rect().height() );
 109     viewRect=QRectF(p0,p1);
 110 }
 111
 112 void Winter::setObstacles(QList <QRectF> obslist)
 113 {
 114     obstacles=obslist;
 115
 116     QList <SnowFlake*> unfreeze;
 117
 118     // Find frozen snowflakes, which are free again
 119     QPointF p;
 120     int i=0;
 121     bool frozen;
 122     while (i < frozenSnow.count())
 123     {
 124         p=frozenSnow.at(i)->pos();
 125         frozen=false;
 126
 127         int j=0;
 128         while (j<obstacles.count() && !frozen)
 129
 130         {
 131             if (obstacles.at(j).contains(p) )
 132                 frozen=true;
 133             j++;
 134         }
 135         if (!frozen)
 136         {
 137             unfreeze.append(frozenSnow.at(i));
 138             frozenSnow.removeAt(i);
 139         } else
 140             i++;
 141     }
 142
 143     // Remove some flakes, if too many
 144     while (fallingSnow.count() + unfreeze.count() > maxFalling + maxUnfreeze)
 145         delete unfreeze.takeFirst();
 146
 147     while (!unfreeze.isEmpty())
 148     {
 149         // Blow a bit up
 150         unfreeze.first()->blow( QPointF(qrand()%10/10.0-0.5, qrand()%10/10.0 -5));
 151         fallingSnow.append(unfreeze.takeFirst());
 152     }
 153 }
 154
 155
 156 void Winter::animate()
 157 {
 158     updateView();
 159     //test->setLine(QLineF(viewRect.topLeft(), viewRect.bottomRight()));
 160
 161     QPointF p;
 162     int i=0;
 163     bool cont;
 164     while (i<fallingSnow.count())
 165     {
 166         p=fallingSnow.at(i)->pos();
 167         cont=true;
 168
 169         int j=0;
 170         while (j<obstacles.count() && cont)
 171         {
 172             if (obstacles.at(j).contains(p) && qrand()%(obstacles.count()+1) > obstacles.count()-1)
 173             {
 174                 // Freeze snowflake on obstacle
 175                 // Probality is equale for obstacles or falling through
 176                 frozenSnow.append(fallingSnow.at(i));
 177                 fallingSnow.removeAt(i);
 178                 cont=false;
 179             }
 180             j++;
 181         }
 182         if (cont && p.y() > viewRect.y() + viewRect.height() + 20)
 183         {
 184             delete fallingSnow.takeAt(i);
 185             cont=false;
 186         }
 187         // Let snowflake fall further
 188         if (cont) fallingSnow.at(i)->animate();
 189         i++;
 190     }
 191 }
 192
 193 void Winter::makeSnow()
 194 {
 195     //qDebug()<<"falling: "<<fallingSnow.count()<<"  frozen: "<<frozenSnow.count();
 196     if (fallingSnow.count() + frozenSnow.count() <maxFlakes)
 197     {
 198         if (fallingSnow.count() < maxFalling)
 199         {
 200             // Create more snowflakes
 201             SnowFlake *snowflake;
 202             for (int i=0; i<10; i++)
 203             {
 204                 snowflake=new SnowFlake(view->scene());
 205                 snowflake->setPos( 0,0);
 206                 snowflake->setRotation(qrand()%60);
 207                 view->scene()->addItem(snowflake);
 208                 snowflake->setPos(
 209                         rand()%round_int(viewRect.width()) + viewRect.x(),
 210                         viewRect.y() -20
 211                 );
 212                 fallingSnow.append(snowflake);
 213             }
 214         }
 215     } else
 216     {
 217         // Remove some of the existing frozen flakes
 218         for (int i=0; i<10; i++)
 219         {
 220             if (frozenSnow.count()>0)
 221             {
 222                 int j=qrand()%frozenSnow.count();
 223                 delete frozenSnow.takeAt(j);
 224             }
 225         }
 226     }
 227
 228 }
 229