As3 How to remove or update bitmapdata for a new level? - actionscript-3

Question

I'm making a maze game. The character can't walk through the walls of the maze (because of a collition detection between the bitmapdata from the character and the bmd from the walls). When the character arrives at a door, the next level/frame should appear with a new maze (new bounds)
For the next level (next frame), I made a new maze with different walls. But the bitmapdata from the first maze is still 'active'. So even though there's a new maze, the bitmapdata from the previous walls is invisible but still drawn on the stage.
My question to you is:
I want to change the bounds/maze every frame, how can I remove the previous bitmapdata so the character won't walk through the bounds of the next maze? Or is it possible to make an array from the different 'bounds'?
stop();
var isRight:Boolean=false;
var isLeft:Boolean=false;
var isUp:Boolean=false;
var isDown:Boolean=false;
var speed:int = 10;
var mazeRect:Rectangle = bounds.getBounds(this);
var charRect:Rectangle = char.getBounds(this);
var boundsBmpData = new BitmapData(mazeRect.width, mazeRect.height, true, 0);
var charBmpData = new BitmapData(charRect.width, charRect.height, true, 0);
boundsBmpData.draw(bounds);
charBmpData.draw(char);
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyPressed);
stage.addEventListener(KeyboardEvent.KEY_UP, keyReleased);
stage.addEventListener(Event.ENTER_FRAME, moving);
function keyPressed(event:KeyboardEvent):void
{
if(event.keyCode==39){
isRight=true}
if(event.keyCode==37){
isLeft=true}
if(event.keyCode==38){
isUp=true}
if(event.keyCode==40){
isDown=true}
}
function keyReleased(event:KeyboardEvent)
{
if(event.keyCode==39){
isRight=false}
if(event.keyCode==37){
isLeft=false}
if(event.keyCode==38){
isUp=false}
if(event.keyCode==40){
isDown=false}
}
function moving(e: Event): void
{
var newx: Number = char.x - (isLeft ? speed : 0) + (isRight ? speed : 0);
var newy: Number = char.y - (isUp ? speed : 0) + (isDown ? speed : 0);
if(!boundsBmpData.hitTest(new Point(bounds.x, bounds.y),
255,
charBmpData,
new Point(newx, newy),
255))
{
char.x = newx;
char.y = newy;
}
if(char.hitTestObject(door))
{
onHitTest();
}
}
function onHitTest() : void
{
nextFrame();
}

Answer 1

Maybe try calling dispose() on old BitmapData first and then create new one?

Answer 2

After looking at the FLA, there were a few issues.
the main one is that though you switched frames, you did not reset your pointers to the bounds object, the door object, and the char object. So you were still tied to the old ones programmatically, though not visually.
I put the declarations into a method called setupFrame(), and call it from your onHitTest() method.
I added a check in onHitTest() to make sure that the bounds object exists in the current frame before setting up the frame. If not, the game stops.
The actions and char layers now extend across the entire game timeline, since they are reused.
char object is now repositioned each frame using points found in the startPts array, instead of having to recreate it each time.
removed the event listeners during the frame setup, and add them at the end of the frame setup. This prevents possible errors from listening to the events.
This is a pretty good effort at creating a simple game engine. Just fyi, gamedev.stackexchange.com is a place devoted to all levels of game development, and you can ask more theoretical questions there.
HTH!