| 1 | /****************************************************************
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| 2 | **
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| 3 | ** Implementation CannonField class, Qt tutorial 11
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| 4 | **
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| 5 | ****************************************************************/
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| 6 |
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| 7 | #include "cannon.h"
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| 8 | #include <qtimer.h>
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| 9 | #include <qpainter.h>
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| 10 | #include <qpixmap.h>
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| 11 |
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| 12 | #include <math.h>
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| 13 |
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| 14 |
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| 15 | CannonField::CannonField( QWidget *parent, const char *name )
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| 16 | : QWidget( parent, name )
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| 17 | {
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| 18 | ang = 45;
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| 19 | f = 0;
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| 20 | timerCount = 0;
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| 21 | autoShootTimer = new QTimer( this, "movement handler" );
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| 22 | connect( autoShootTimer, SIGNAL(timeout()),
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| 23 | this, SLOT(moveShot()) );
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| 24 | shoot_ang = 0;
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| 25 | shoot_f = 0;
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| 26 | setPalette( QPalette( QColor( 250, 250, 200) ) );
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| 27 | }
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| 28 |
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| 29 |
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| 30 | void CannonField::setAngle( int degrees )
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| 31 | {
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| 32 | if ( degrees < 5 )
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| 33 | degrees = 5;
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| 34 | if ( degrees > 70 )
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| 35 | degrees = 70;
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| 36 | if ( ang == degrees )
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| 37 | return;
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| 38 | ang = degrees;
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| 39 | repaint( cannonRect(), FALSE );
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| 40 | emit angleChanged( ang );
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| 41 | }
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| 42 |
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| 43 |
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| 44 | void CannonField::setForce( int newton )
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| 45 | {
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| 46 | if ( newton < 0 )
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| 47 | newton = 0;
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| 48 | if ( f == newton )
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| 49 | return;
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| 50 | f = newton;
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| 51 | emit forceChanged( f );
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| 52 | }
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| 53 |
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| 54 |
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| 55 | void CannonField::shoot()
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| 56 | {
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| 57 | if ( autoShootTimer->isActive() )
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| 58 | return;
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| 59 | timerCount = 0;
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| 60 | shoot_ang = ang;
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| 61 | shoot_f = f;
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| 62 | autoShootTimer->start( 50 );
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| 63 | }
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| 64 |
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| 65 |
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| 66 | void CannonField::moveShot()
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| 67 | {
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| 68 | QRegion r( shotRect() );
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| 69 | timerCount++;
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| 70 |
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| 71 | QRect shotR = shotRect();
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| 72 |
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| 73 | if ( shotR.x() > width() || shotR.y() > height() )
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| 74 | autoShootTimer->stop();
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| 75 | else
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| 76 | r = r.unite( QRegion( shotR ) );
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| 77 | repaint( r );
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| 78 | }
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| 79 |
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| 80 |
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| 81 | void CannonField::paintEvent( QPaintEvent *e )
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| 82 | {
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| 83 | QRect updateR = e->rect();
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| 84 | QPainter p( this );
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| 85 |
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| 86 | if ( updateR.intersects( cannonRect() ) )
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| 87 | paintCannon( &p );
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| 88 | if ( autoShootTimer->isActive() &&
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| 89 | updateR.intersects( shotRect() ) )
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| 90 | paintShot( &p );
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| 91 | }
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| 92 |
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| 93 |
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| 94 | void CannonField::paintShot( QPainter *p )
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| 95 | {
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| 96 | p->setBrush( black );
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| 97 | p->setPen( NoPen );
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| 98 | p->drawRect( shotRect() );
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| 99 | }
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| 100 |
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| 101 |
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| 102 | const QRect barrelRect(33, -4, 15, 8);
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| 103 |
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| 104 | void CannonField::paintCannon( QPainter *p )
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| 105 | {
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| 106 | QRect cr = cannonRect();
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| 107 | QPixmap pix( cr.size() );
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| 108 | pix.fill( this, cr.topLeft() );
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| 109 |
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| 110 | QPainter tmp( &pix );
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| 111 | tmp.setBrush( blue );
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| 112 | tmp.setPen( NoPen );
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| 113 |
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| 114 | tmp.translate( 0, pix.height() - 1 );
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| 115 | tmp.drawPie( QRect( -35,-35, 70, 70 ), 0, 90*16 );
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| 116 | tmp.rotate( -ang );
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| 117 | tmp.drawRect( barrelRect );
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| 118 | tmp.end();
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| 119 |
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| 120 | p->drawPixmap( cr.topLeft(), pix );
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| 121 | }
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| 122 |
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| 123 |
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| 124 | QRect CannonField::cannonRect() const
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| 125 | {
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| 126 | QRect r( 0, 0, 50, 50 );
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| 127 | r.moveBottomLeft( rect().bottomLeft() );
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| 128 | return r;
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| 129 | }
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| 130 |
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| 131 |
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| 132 | QRect CannonField::shotRect() const
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| 133 | {
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| 134 | const double gravity = 4;
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| 135 |
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| 136 | double time = timerCount / 4.0;
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| 137 | double velocity = shoot_f;
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| 138 | double radians = shoot_ang*3.14159265/180;
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| 139 |
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| 140 | double velx = velocity*cos( radians );
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| 141 | double vely = velocity*sin( radians );
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| 142 | double x0 = ( barrelRect.right() + 5 )*cos(radians);
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| 143 | double y0 = ( barrelRect.right() + 5 )*sin(radians);
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| 144 | double x = x0 + velx*time;
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| 145 | double y = y0 + vely*time - 0.5*gravity*time*time;
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| 146 |
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| 147 | QRect r = QRect( 0, 0, 6, 6 );
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| 148 | r.moveCenter( QPoint( qRound(x), height() - 1 - qRound(y) ) );
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| 149 | return r;
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| 150 | }
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| 151 |
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| 152 |
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| 153 | QSizePolicy CannonField::sizePolicy() const
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| 154 | {
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| 155 | return QSizePolicy( QSizePolicy::Expanding, QSizePolicy::Expanding );
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| 156 | }
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