Hiya, right now I’m trying to throw together a simple bouncing ball application, here’s what I have so far:
A Ball.as class file which handles the movement of balls around the stage and their bouncing off of the boundaries of the stage:
package {
//import necessary classes
import flash.display.MovieClip;
import flash.events.Event;
import flash.geom.Rectangle;
public class Ball extends MovieClip{
//horizontal speed and direction
public var speedX:int = -10;
//vertical speed and direction
public var speedY:int = -10;
//constructor
public function Ball() {
addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
//called every frame
private function onEnterFrame(event:Event):void {
//move ball by appropriate amount based on the x/y speed variable
x += speedX;
y += speedY;
//get boundary rectangle for ball
var bounds:Rectangle = getBounds(parent);
// reverse horizontal direction if collided with left or right of stage
if (bounds.left < 0 || bounds.right > stage.stageWidth) {
speedX *= -1;
}
//reverse vertical direction if collision with top or bottom
if (bounds.top < 0 || bounds.bottom > stage.stageHeight) {
speedY *= -1;
}
}
}
}
A BallControl.as class which handles the creation of a new ball, either a blue or a red ball depending on the number generated by math.random ever second, limited to 20 on the stage at any 1 time:
package {
//import the necessary classes
import flash.display.MovieClip;
import flash.utils.Timer;
import flash.events.TimerEvent;
import flash.geom.ColorTransform;
import flash.events.Event;
public class BallControl extends MovieClip {
//total number of balls
private var ballnum: int = 0;
//declares the timer variable, used to create a new timer which handles the creation of the balls
private var timer:Timer;
//declares blue and red arrays, which will store information about the respective ball colors
private var blueArray: Array = new Array;
private var redArray: Array = new Array;
//i and j variables, which will increase with the blue and red array's lengths
private var i: int= 0;
private var j: int = 0;
//constructor
public function BallControl() {
//creates and starts a new timer which will initialize the mainloop event every second
timer = new Timer(1000);
timer.addEventListener(TimerEvent.TIMER, mainloop);
timer.start();
stage.addEventListener(Event.ENTER_FRAME, hittest);
}
//the mainloop function which is called at each timer interval
private function mainloop(timer:TimerEvent):void {
//if the number of balls on the stage is less then 20 the function will occur
if (ballnum < 20) {
//the redball and blueball objects are instances of the Ball class
var redball:Ball = new Ball();
var blueball:Ball = new Ball();
//creates a net color transform variable, used to manipulate the color of the blue and red balls
var colourTransform:ColorTransform = new ColorTransform();
//if the number generated by math random is greated then .5
if (Math.random() > .5)
{
//set the ball's color to blue
colourTransform.color = 0x0000ff;
blueball.transform.colorTransform = colourTransform;
//place the ball in the centre of the stage
blueball.x = stage.stageWidth/2;
blueball.y = stage.stageHeight/2;
//specify random speed and direction
blueball.speedX = (Math.random() * 30) - 15;
blueball.speedY = (Math.random() * 30) - 15;
//add the blue ball to the stage
addChild(blueball);
//adds the blue ball to the blueArray
blueArray.push(blueball);
//increases the i variable by 1
i+
//increases the total number of balls by 1
ballnum++;
}
//if the random number generated is less then .5
else if (Math.random() < .5) {
//set the ball's color to red
colourTransform.color = 0xff0000;
redball.transform.colorTransform = colourTransform;
//place it in the centre of the stage
redball.x = stage.stageWidth/2;
redball.y = stage.stageHeight/2;
//set a random speed and direction
redball.speedX = (Math.random() * 30);
redball.speedY = (Math.random() * 30);
//add a red ball to the stage
addChild(redball);
//adds the red ball to the redArray
redArray.push(redball)
//increases j by 1
j ++;
//increases the total number of balls by 1
ballnum ++;
}
}
}
private function hittest (event:Event):void {
if (blueArray*.hitTestObject(redArray[j]))
{trace("Test")}
}
}
}
And an fla file containing no actionscript, just the ball movieclip, and the fla file’s document class is set to the BallControl.as file.
The problem is when I run the file, the blue and red balls are created just as expected, but when it comes to the hittest of a red and a blue ball, I get these 2 errors:
TypeError: Error #1010: A term is undefined and has no properties.
at BallControl/::hittest()
TypeError: Error #2007: Parameter hitTestObject must be non-null.
at flash.display:: DisplayObject/flash.display: DisplayObject::_hitTest()
at flash.display:: DisplayObject/hitTestObject()
at BallControl/::hittest()
So it’s pretty clear that something’s wrong in the hittest function, I’m just not sure how to fix it, any help would greatly be appreciated since I’m not that experienced with AS3. Thanks in advance
