1 files changed, 173 insertions, 0 deletions
diff --git a/qtruby/rubylib/tutorial/t12/cannon.rb b/qtruby/rubylib/tutorial/t12/cannon.rb
new file mode 100644
index 00000000..1b72cbc0
--- /dev/null
+++ b/qtruby/rubylib/tutorial/t12/cannon.rb
@@ -0,0 +1,173 @@
+include Math
+require 'Qt'
+
+class CannonField < Qt::Widget
+    
+    signals 'hit()', 'missed()', 'angleChanged(int)', 'forceChanged(int)'
+    slots 'setAngle(int)', 'setForce(int)', 'shoot()', 'moveShot()', 'newTarget()'
+    
+    def initialize(parent, name)
+        super
+        @ang = 45
+        @f = 0
+        @timerCount = 0;
+        @autoShootTimer = Qt::Timer.new( self, 'movement handler' )
+        connect( @autoShootTimer, SIGNAL('timeout()'),
+                 self, SLOT('moveShot()') );
+        @shoot_ang = 0
+        @shoot_f = 0
+        @target = Qt::Point.new(0, 0)        
+        setPalette( Qt::Palette.new( Qt::Color.new( 250, 250, 200) ) )
+        newTarget()
+        @barrelRect = Qt::Rect.new(33, -4, 15, 8)
+    end
+
+    def setAngle( degrees )
+        if degrees < 5
+            degrees = 5
+        elsif degrees > 70
+            degrees = 70
+        end
+        if @ang == degrees
+            return
+        end
+        @ang = degrees
+        repaint( cannonRect(), false )
+        emit angleChanged( @ang )
+    end
+    
+    def setForce( newton )
+        if newton < 0
+            newton = 0
+        end
+        if @f == newton
+            return
+        end
+        @f = newton
+        emit forceChanged( @f )
+    end
+    
+    def shoot()
+        if @autoShootTimer.isActive()
+            return
+        end;
+        @timerCount = 0
+        @shoot_ang = @ang
+        @shoot_f = @f
+        @autoShootTimer.start( 50 )
+    end
+
+    @@first_time = true
+    
+    def newTarget()
+        if @@first_time
+            @@first_time = false
+            midnight = Qt::Time.new( 0, 0, 0 )
+            srand( midnight.secsTo(Qt::Time.currentTime()) )
+        end
+        r = Qt::Region.new( targetRect() )
+        @target = Qt::Point.new( 200 + rand(190),
+                     10  + rand(255) )
+        repaint( r.unite( Qt::Region.new(targetRect()) ) )
+    end
+    
+    def moveShot()
+        r = Qt::Region.new( shotRect() )
+        @timerCount += 1
+
+        shotR = shotRect()
+
+        if shotR.intersects( targetRect() ) 
+            @autoShootTimer.stop()
+            emit hit()
+        elsif shotR.x() > width() || shotR.y() > height()
+            @autoShootTimer.stop()
+            emit missed()
+        else
+            r = r.unite( Qt::Region.new( shotR ) )
+        end
+        
+        repaint( r )
+    end
+
+    def paintEvent( e )
+        updateR = e.rect()
+        p = Qt::Painter.new( self )
+
+        if updateR.intersects( cannonRect() )
+            paintCannon( p )
+        end
+        if @autoShootTimer.isActive() &&
+             updateR.intersects( shotRect() )
+            paintShot( p )
+        end        
+        if updateR.intersects( targetRect() )
+            paintTarget( p )
+        end
+        p.end()
+    end
+
+    def paintShot( p )
+        p.setBrush( black )
+        p.setPen( Qt::NoPen )
+        p.drawRect( shotRect() )
+    end
+
+    def paintTarget( p )
+        p.setBrush( red )
+        p.setPen( black )
+        p.drawRect( targetRect() )
+    end
+    
+    def paintCannon(p)                
+        cr = cannonRect()
+        pix = Qt::Pixmap.new( cr.size() )
+        pix.fill( self, cr.topLeft() )
+        
+        tmp = Qt::Painter.new( pix )
+        tmp.setBrush( blue )
+        tmp.setPen( Qt::NoPen )
+        tmp.translate( 0, pix.height() - 1 )
+        tmp.drawPie( Qt::Rect.new(-35, -35, 70, 70), 0, 90*16 )
+        tmp.rotate( - @ang )
+        tmp.drawRect( @barrelRect )
+        tmp.end()
+        
+        p.drawPixmap(cr.topLeft(), pix )        
+    end
+
+    def cannonRect()
+        r = Qt::Rect.new( 0, 0, 50, 50)
+        r.moveBottomLeft( rect().bottomLeft() )
+        return r
+    end
+    
+    def shotRect()
+        gravity = 4.0
+
+        time      = @timerCount / 4.0
+        velocity  = @shoot_f
+        radians   = @shoot_ang*3.14159265/180.0
+
+        velx      = velocity*cos( radians )
+        vely      = velocity*sin( radians )
+        x0        = ( @barrelRect.right()  + 5.0 )*cos(radians)
+        y0        = ( @barrelRect.right()  + 5.0 )*sin(radians)
+        x         = x0 + velx*time
+        y         = y0 + vely*time - 0.5*gravity*time*time
+
+        r = Qt::Rect.new( 0, 0, 6, 6 );
+        r.moveCenter( Qt::Point.new( x.round, height() - 1 - y.round ) )
+        return r
+    end
+
+    def targetRect()
+        r = Qt::Rect.new( 0, 0, 20, 10 )
+        r.moveCenter( Qt::Point.new(@target.x(),height() - 1 - @target.y()) );
+        return r
+    end
+    
+    def sizePolicy()
+        return Qt::SizePolicy.new( Qt::SizePolicy::Expanding, Qt::SizePolicy::Expanding )
+    end
+end