topical media & game development
lib-flex-animation-code-02-com-foed-Vehicle.ax
lib-flex-animation-code-02-com-foed-Vehicle.ax
(swf
)
[ flash
]
flex
package com.foed
{
import flash.display.Sprite;
Base class for moving characters.
public class @ax-lib-flex-animation-code-02-com-foed-Vehicle extends Sprite
{
protected var _edgeBehavior:String = WRAP;
protected var _mass:Number = 1.0;
protected var _maxSpeed:Number = 10;
protected var _position:Vector2D;
protected var _velocity:Vector2D;
// potential edge behaviors
public static const WRAP:String = "wrap";
public static const BOUNCE:String = "bounce";
Constructor.
public function @ax-lib-flex-animation-code-02-com-foed-Vehicle()
{
_position = new Vector2D();
_velocity = new Vector2D();
draw();
}
Default graphics for vehicle. Can be overridden in subclasses.
protected function draw():void
{
graphics.clear();
graphics.lineStyle(0);
graphics.moveTo(10, 0);
graphics.lineTo(-10, 5);
graphics.lineTo(-10, -5);
graphics.lineTo(10, 0);
}
Handles all basic motion. Should be called on each frame / timer interval.
public function update():void
{
// make sure velocity stays within max speed.
_velocity.truncate(_maxSpeed);
// add velocity to position
_position = _position.add(_velocity);
// handle any edge behavior
if(_edgeBehavior == WRAP)
{
wrap();
}
else if(_edgeBehavior == BOUNCE)
{
bounce();
}
// update position of sprite
x = position.x;
y = position.y;
// rotate heading to match velocity
rotation = _velocity.angle * 180 / Math.PI;
}
Causes character to bounce off edge if edge is hit.
private function bounce():void
{
if(stage != null)
{
if(position.x > stage.stageWidth)
{
position.x = stage.stageWidth;
velocity.x *= -1;
}
else if(position.x < 0)
{
position.x = 0;
velocity.x *= -1;
}
if(position.y > stage.stageHeight)
{
position.y = stage.stageHeight;
velocity.y *= -1;
}
else if(position.y < 0)
{
position.y = 0;
velocity.y *= -1;
}
}
}
Causes character to wrap around to opposite edge if edge is hit.
private function wrap():void
{
if(stage != null)
{
if(position.x > stage.stageWidth) position.x = 0;
if(position.x < 0) position.x = stage.stageWidth;
if(position.y > stage.stageHeight) position.y = 0;
if(position.y < 0) position.y = stage.stageHeight;
}
}
Sets / gets what will happen if character hits edge.
public function set edgeBehavior(value:String):void
{
_edgeBehavior = value;
}
public function get edgeBehavior():String
{
return _edgeBehavior;
}
Sets / gets mass of character.
public function set mass(value:Number):void
{
_mass = value;
}
public function get mass():Number
{
return _mass;
}
Sets / gets maximum speed of character.
public function set maxSpeed(value:Number):void
{
_maxSpeed = value;
}
public function get maxSpeed():Number
{
return _maxSpeed;
}
Sets / gets position of character as a Vector2D.
public function set position(value:Vector2D):void
{
_position = value;
x = _position.x;
y = _position.y;
}
public function get position():Vector2D
{
return _position;
}
Sets / gets velocity of character as a Vector2D.
public function set velocity(value:Vector2D):void
{
_velocity = value;
}
public function get velocity():Vector2D
{
return _velocity;
}
Sets x position of character. Overrides Sprite.x to set internal Vector2D position as well.
override public function set x(value:Number):void
{
super.x = value;
_position.x = x;
}
Sets y position of character. Overrides Sprite.y to set internal Vector2D position as well.
override public function set y(value:Number):void
{
super.y = value;
_position.y = y;
}
}
}
(C) Æliens
18/6/2009
You may not copy or print any of this material without explicit permission of the author or the publisher.
In case of other copyright issues, contact the author.
