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<pre>/****************************************************************
**
** Implementation CannonField class, Qt tutorial 13
**
****************************************************************/
#include "cannon.h"
#include <<a href="qtimer-h.html">qtimer.h</a>>
#include <<a href="qpainter-h.html">qpainter.h</a>>
#include <<a href="qpixmap-h.html">qpixmap.h</a>>
#include <<a href="qdatetime-h.html">qdatetime.h</a>>
#include <math.h>
#include <stdlib.h>
<a name="f77"></a>CannonField::CannonField( <a href="qwidget.html">QWidget</a> *parent, const char *name )
: <a href="qwidget.html">QWidget</a>( parent, name )
{
ang = 45;
f = 0;
timerCount = 0;
autoShootTimer = new <a href="qtimer.html">QTimer</a>( this, "movement handler" );
<a href="qobject.html#connect">connect</a>( autoShootTimer, SIGNAL(<a href="qtimer.html#timeout">timeout</a>()),
this, SLOT(moveShot()) );
shoot_ang = 0;
shoot_f = 0;
target = QPoint( 0, 0 );
gameEnded = FALSE;
<a href="qwidget.html#setPalette">setPalette</a>( QPalette( QColor( 250, 250, 200) ) );
newTarget();
}
void <a name="f78"></a>CannonField::setAngle( int degrees )
{
if ( degrees < 5 )
degrees = 5;
if ( degrees > 70 )
degrees = 70;
if ( ang == degrees )
return;
ang = degrees;
<a href="qwidget.html#repaint">repaint</a>( cannonRect(), FALSE );
emit angleChanged( ang );
}
void <a name="f79"></a>CannonField::setForce( int newton )
{
if ( newton < 0 )
newton = 0;
if ( f == newton )
return;
f = newton;
emit forceChanged( f );
}
void <a name="f80"></a>CannonField::shoot()
{
if ( isShooting() )
return;
timerCount = 0;
shoot_ang = ang;
shoot_f = f;
autoShootTimer-><a href="qtimer.html#start">start</a>( 50 );
emit canShoot( FALSE );
}
void <a name="f81"></a>CannonField::newTarget()
{
static bool first_time = TRUE;
if ( first_time ) {
first_time = FALSE;
<a href="qtime.html">QTime</a> midnight( 0, 0, 0 );
srand( midnight.<a href="qtime.html#secsTo">secsTo</a>(QTime::<a href="qtime.html#currentTime">currentTime</a>()) );
}
<a href="qregion.html">QRegion</a> r( targetRect() );
target = QPoint( 200 + rand() % 190,
10 + rand() % 255 );
<a href="qwidget.html#repaint">repaint</a>( r.<a href="qrect.html#unite">unite</a>( targetRect() ) );
}
void <a name="f82"></a>CannonField::setGameOver()
{
if ( gameEnded )
return;
if ( isShooting() )
autoShootTimer-><a href="qtimer.html#stop">stop</a>();
gameEnded = TRUE;
<a href="qwidget.html#repaint">repaint</a>();
}
void <a name="f83"></a>CannonField::restartGame()
{
if ( isShooting() )
autoShootTimer-><a href="qtimer.html#stop">stop</a>();
gameEnded = FALSE;
<a href="qwidget.html#repaint">repaint</a>();
emit canShoot( TRUE );
}
void <a name="f84"></a>CannonField::moveShot()
{
<a href="qregion.html">QRegion</a> r( shotRect() );
timerCount++;
<a href="qrect.html">QRect</a> shotR = shotRect();
if ( shotR.<a href="qrect.html#intersects">intersects</a>( targetRect() ) ) {
autoShootTimer-><a href="qtimer.html#stop">stop</a>();
emit hit();
emit canShoot( TRUE );
} else if ( shotR.<a href="qrect.html#x">x</a>() > width() || shotR.<a href="qrect.html#y">y</a>() > height() ) {
autoShootTimer-><a href="qtimer.html#stop">stop</a>();
emit missed();
emit canShoot( TRUE );
} else {
r = r.<a href="qrect.html#unite">unite</a>( QRegion( shotR ) );
}
<a href="qwidget.html#repaint">repaint</a>( r );
}
void CannonField::<a href="qwidget.html#paintEvent">paintEvent</a>( <a href="qpaintevent.html">QPaintEvent</a> *e )
{
<a href="qrect.html">QRect</a> updateR = e-><a href="qpaintevent.html#rect">rect</a>();
<a href="qpainter.html">QPainter</a> p( this );
if ( gameEnded ) {
p.<a href="qpainter.html#setPen">setPen</a>( black );
p.<a href="qpainter.html#setFont">setFont</a>( QFont( "Courier", 48, QFont::Bold ) );
p.<a href="qpainter.html#drawText">drawText</a>( <a href="qwidget.html#rect">rect</a>(), AlignCenter, "Game Over" );
}
if ( updateR.<a href="qrect.html#intersects">intersects</a>( cannonRect() ) )
paintCannon( &p );
if ( isShooting() && updateR.<a href="qrect.html#intersects">intersects</a>( shotRect() ) )
paintShot( &p );
if ( !gameEnded && updateR.<a href="qrect.html#intersects">intersects</a>( targetRect() ) )
paintTarget( &p );
}
void <a name="f85"></a>CannonField::paintShot( <a href="qpainter.html">QPainter</a> *p )
{
p-><a href="qpainter.html#setBrush">setBrush</a>( black );
p-><a href="qpainter.html#setPen">setPen</a>( NoPen );
p-><a href="qpainter.html#drawRect">drawRect</a>( shotRect() );
}
void <a name="f86"></a>CannonField::paintTarget( <a href="qpainter.html">QPainter</a> *p )
{
p-><a href="qpainter.html#setBrush">setBrush</a>( red );
p-><a href="qpainter.html#setPen">setPen</a>( black );
p-><a href="qpainter.html#drawRect">drawRect</a>( targetRect() );
}
const <a href="qrect.html">QRect</a> barrelRect(33, -4, 15, 8);
void <a name="f87"></a>CannonField::paintCannon( <a href="qpainter.html">QPainter</a> *p )
{
<a href="qrect.html">QRect</a> cr = cannonRect();
<a href="qpixmap.html">QPixmap</a> pix( cr.<a href="qrect.html#size">size</a>() );
pix.<a href="qpixmap.html#fill">fill</a>( this, cr.<a href="qrect.html#topLeft">topLeft</a>() );
<a href="qpainter.html">QPainter</a> tmp( &pix );
tmp.<a href="qpainter.html#setBrush">setBrush</a>( blue );
tmp.<a href="qpainter.html#setPen">setPen</a>( NoPen );
tmp.<a href="qpainter.html#translate">translate</a>( 0, pix.<a href="qpixmap.html#height">height</a>() - 1 );
tmp.<a href="qpainter.html#drawPie">drawPie</a>( QRect( -35,-35, 70, 70 ), 0, 90*16 );
tmp.<a href="qpainter.html#rotate">rotate</a>( -ang );
tmp.<a href="qpainter.html#drawRect">drawRect</a>( barrelRect );
tmp.<a href="qpainter.html#end">end</a>();
p-><a href="qpainter.html#drawPixmap">drawPixmap</a>( cr.<a href="qrect.html#topLeft">topLeft</a>(), pix );
}
QRect <a name="f88"></a>CannonField::cannonRect() const
{
<a href="qrect.html">QRect</a> r( 0, 0, 50, 50 );
r.<a href="qrect.html#moveBottomLeft">moveBottomLeft</a>( <a href="qwidget.html#rect">rect</a>().bottomLeft() );
return r;
}
QRect <a name="f89"></a>CannonField::shotRect() const
{
const double gravity = 4;
double time = timerCount / 4.0;
double velocity = shoot_f;
double radians = shoot_ang*3.14159265/180;
double velx = velocity*cos( radians );
double vely = velocity*sin( radians );
double x0 = ( barrelRect.<a href="qrect.html#right">right</a>() + 5 )*cos(radians);
double y0 = ( barrelRect.<a href="qrect.html#right">right</a>() + 5 )*sin(radians);
double x = x0 + velx*time;
double y = y0 + vely*time - 0.5*gravity*time*time;
<a href="qrect.html">QRect</a> r = QRect( 0, 0, 6, 6 );
r.<a href="qrect.html#moveCenter">moveCenter</a>( QPoint( qRound(x), height() - 1 - qRound(y) ) );
return r;
}
QRect <a name="f90"></a>CannonField::targetRect() const
{
<a href="qrect.html">QRect</a> r( 0, 0, 20, 10 );
r.<a href="qrect.html#moveCenter">moveCenter</a>( QPoint(target.x(),height() - 1 - target.y()) );
return r;
}
bool <a name="f91"></a>CannonField::isShooting() const
{
return autoShootTimer-><a href="qtimer.html#isActive">isActive</a>();
}
QSizePolicy CannonField::<a href="qwidget.html#sizePolicy">sizePolicy</a>() const
{
return QSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
}
</pre><!-- eof -->
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