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#include "tankitem.h"
#include <QPainter>
#include <QGraphicsScene>
#include <math.h>
#ifndef M_PI
#define M_PI 3.14159265358979323846
#endif
class Action
{
public:
Action(TankItem *item) : m_item(item)
{
}
TankItem *item() const { return m_item; }
void setItem(TankItem *item) { m_item = item; }
virtual bool apply(qreal timeDelta) = 0;
private:
TankItem *m_item;
};
class MoveAction: public Action
{
public:
MoveAction(TankItem *item, qreal distance)
: Action(item), m_distance(distance)
{
m_reverse = m_distance < 0.0;
}
bool apply(qreal timeDelta)
{
qreal dist = timeDelta * item()->speed() * (m_reverse ? -1.0 : 1.0);
m_distance -= dist;
if (m_reverse && m_distance > 0.0)
return false;
else if (!m_reverse && m_distance < 0.0)
return false;
qreal a = item()->direction() * M_PI / 180.0;
qreal yd = dist * sin(a);
qreal xd = dist * sin(M_PI / 2.0 - a);
item()->setPos(item()->pos() + QPointF(xd, yd));
return true;
}
private:
qreal m_distance;
bool m_reverse;
};
class TurnAction: public Action
{
public:
TurnAction(TankItem *item, qreal distance)
: Action(item), m_distance(distance)
{
m_reverse = m_distance < 0.0;
}
bool apply(qreal timeDelta)
{
qreal dist = timeDelta * item()->angularSpeed() * (m_reverse ? -1.0 : 1.0);
m_distance -= dist;
if (m_reverse && m_distance > 0.0)
return false;
else if (!m_reverse && m_distance < 0.0)
return false;
item()->setDirection(item()->direction() + dist);
return true;
}
private:
qreal m_distance;
bool m_reverse;
};
TankItem::TankItem(QObject *parent)
: GameItem(parent), m_currentAction(0), m_currentDirection(0.0), m_enabled(true)
{
connect(this, SIGNAL(cannonFired()), this, SIGNAL(actionCompleted()));
}
void TankItem::idle(qreal elapsed)
{
if (m_enabled) {
if (m_currentAction != 0) {
if (!m_currentAction->apply(elapsed)) {
setAction(0);
emit actionCompleted();
}
QGraphicsItem *item = 0;
qreal distance = distanceToObstacle(&item);
if (TankItem *tankItem = qgraphicsitem_cast<TankItem *>(item))
emit tankSpotted(tankItem->direction(), distance);
}
}
}
void TankItem::hitByRocket()
{
deleteLater();
}
void TankItem::setAction(Action *newAction)
{
if (m_currentAction != 0)
delete m_currentAction;
m_currentAction = newAction;
}
void TankItem::fireCannon()
{
emit cannonFired();
}
void TankItem::moveForwards(qreal length)
{
setAction(new MoveAction(this, length));
}
void TankItem::moveBackwards(qreal length)
{
setAction(new MoveAction(this, -length));
}
void TankItem::turn(qreal degrees)
{
setAction(new TurnAction(this, degrees));
}
void TankItem::turnTo(qreal degrees)
{
setAction(new TurnAction(this, degrees - direction()));
}
void TankItem::stop()
{
setAction(0);
}
QVariant TankItem::itemChange(QGraphicsItem::GraphicsItemChange change, const QVariant &value)
{
if (change == ItemPositionChange && scene()) {
QPointF requestedPosition = value.toPointF();
QLineF collidedLine;
QPointF nextPoint = tryMove(requestedPosition, &collidedLine);
if (nextPoint != requestedPosition)
emit collision(collidedLine);
return nextPoint;
} else {
return QGraphicsItem::itemChange(change, value);
}
}
void TankItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
{
QRectF brect = boundingRect();
painter->setBrush(m_color);
painter->setPen(Qt::black);
// body
painter->drawRect(brect.adjusted(0.0, 4.0, -2.0, -4.0));
// cannon
QRectF cannonBase = brect.adjusted(10.0, 6.0, -12.0, -6.0);
painter->drawEllipse(cannonBase);
painter->drawRect(QRectF(QPointF(cannonBase.center().x(), cannonBase.center().y() - 2.0),
QPointF(brect.right(), cannonBase.center().y() + 2.0)));
// left track
painter->setBrush(QBrush(Qt::black, Qt::VerPattern));
QRectF leftTrackRect = QRectF(brect.topLeft(), QPointF(brect.right() - 2.0, brect.top() + 4.0));
painter->fillRect(leftTrackRect, Qt::darkYellow);
painter->drawRect(leftTrackRect);
// right track
QRectF rightTrackRect = QRectF(QPointF(brect.left(), brect.bottom() - 4.0),
QPointF(brect.right() - 2.0, brect.bottom()));
painter->fillRect(rightTrackRect, Qt::darkYellow);
painter->drawRect(rightTrackRect);
if (!m_enabled) {
painter->setPen(QPen(Qt::red, 5));
painter->drawEllipse(brect);
QPainterPath path;
path.addEllipse(brect);
painter->setClipPath(path);
painter->drawLine(brect.topRight(), brect.bottomLeft());
}
}
QRectF TankItem::boundingRect() const
{
return QRectF(-20.0, -10.0, 40.0, 20.0);
}
qreal TankItem::direction() const
{
return m_currentDirection;
}
void TankItem::setDirection(qreal newDirection)
{
qreal diff = newDirection - m_currentDirection;
m_currentDirection = newDirection;
rotate(diff);
}
qreal TankItem::distanceToObstacle(QGraphicsItem **obstacle) const
{
qreal dist = sqrt(pow(scene()->sceneRect().width(), 2) + pow(scene()->sceneRect().height(), 2));
qreal a = m_currentDirection * M_PI / 180.0;
qreal yd = dist * sin(a);
qreal xd = dist * sin(M_PI / 2.0 - a);
QPointF requestedPosition = pos() + QPointF(xd, yd);
QGraphicsItem *collidedItem = 0;
QPointF nextPosition = tryMove(requestedPosition, 0, &collidedItem);
if (collidedItem != 0) {
if (obstacle != 0)
*obstacle = collidedItem;
QPointF d = nextPosition - pos();
return sqrt(pow(d.x(), 2) + pow(d.y(), 2));
} else {
return 0.0;
}
}
qreal TankItem::distanceToObstacle() const
{
return distanceToObstacle(0);
}
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