<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/tutorial.doc:1708 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>t12/cannon.cpp Example File</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>t12/cannon.cpp Example File</h1> <pre>/**************************************************************** ** ** Implementation CannonField class, Qt tutorial 12 ** ****************************************************************/ #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="f74"></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 ); <a href="qwidget.html#setPalette">setPalette</a>( QPalette( QColor( 250, 250, 200) ) ); newTarget(); } void <a name="f75"></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="f76"></a>CannonField::setForce( int newton ) { if ( newton < 0 ) newton = 0; if ( f == newton ) return; f = newton; emit forceChanged( f ); } void <a name="f77"></a>CannonField::shoot() { if ( autoShootTimer-><a href="qtimer.html#isActive">isActive</a>() ) return; timerCount = 0; shoot_ang = ang; shoot_f = f; autoShootTimer-><a href="qtimer.html#start">start</a>( 50 ); } void <a name="f78"></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="f79"></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(); } 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(); } 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 ( updateR.<a href="qrect.html#intersects">intersects</a>( cannonRect() ) ) paintCannon( &p ); if ( autoShootTimer-><a href="qtimer.html#isActive">isActive</a>() && updateR.<a href="qrect.html#intersects">intersects</a>( shotRect() ) ) paintShot( &p ); if ( updateR.<a href="qrect.html#intersects">intersects</a>( targetRect() ) ) paintTarget( &p ); } void <a name="f80"></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="f81"></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="f82"></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="f83"></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="f84"></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="f85"></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; } QSizePolicy CannonField::<a href="qwidget.html#sizePolicy">sizePolicy</a>() const { return QSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding ); } </pre><!-- eof --> <p><address><hr><div align=center> <table width=100% cellspacing=0 border=0><tr> <td>Copyright © 2007 <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> <td align=right><div align=right>Qt 3.3.8</div> </table></div></address></body> </html>