Camera and enemy behaviour in AS3 platformer

Question

beginner in AS3 here. I am working on a platformer game based on the code of a provided example exercise. I have the following problem:

• I have an enemy who shoots bullets. The enemy is the parent, and the bullet are the child. When I move to the next scene (level), the bullets are still there, but invisible, even using the removeEventListener to shut down the bullet hit check.

Here is the code of the child "disparoEnemigo_mov":

addEventListener(Event.ENTER_FRAME, fl_MoveEnemyShot);
function fl_MoveEnemyShot(event: Event) {
try {
    if (enemy_shot.y < 300) {
        if (enemy_shot.hitTestObject(Object(this.parent).mario)) {

            variablesGlobales.variables().vidas -= 1;
            Object(root).texto.text = 
variablesGlobales.variables().vidas.toString();
            trace("vidas: " + variablesGlobales.variables().vidas);
            if (variablesGlobales.variables().vidas < 1) {
                MovieClip(this.parent).gotoAndStop(2);
            }
            this.parent.removeChild(this);
            removeEventListener(Event.ENTER_FRAME, fl_MoveEnemyShot);
        } else {
            enemy_shot.y += 3;
        }
    } else {
        trace("LLEGADA");
        removeEventListener(Event.ENTER_FRAME, fl_MoveEnemyShot);
        this.parent.removeChild(this);
    }
} catch (error: Error) {
    removeEventListener(Event.ENTER_FRAME, fl_MoveEnemyShot);
}
}


import flash.events.Event;
import flash.media.SoundMixer;

addEventListener(Event.ENTER_FRAME, fl_EnterFrameHandler);

function fl_EnterFrameHandler(event: Event): void {
try{
if (this.hitTestObject(Object(this.parent).mario)) {

    SoundMixer.stopAll();
    var sound:gameOver = new gameOver();
    sound.play();
    Object(this.parent).mario.y=1000;
    Object(this.parent).mario.x-=15;
    trace("Mario dies");
    var cartel:StageLose = new StageLose();
    stage.addChild(cartel);
    cartel.x = -85;
    Object(this.parent).mario.y = 1000;
    }
}catch(error: Error){
removeEventListener (Event.ENTER_FRAME, fl_EnterFrameHandler);
}
}

And this is the code of the parent, "enemigo_mov":

var leftPressed: Boolean = true;
var rightPressed: Boolean = false;
stage.addEventListener(Event.ENTER_FRAME, fl_MoveEnemy);
function fl_MoveEnemy(event: Event) {
try{
if (leftPressed) {
    enemy1.x -= 0;
    if (enemy1.x < -120) {
        leftPressed = false;
        rightPressed = true;
    }
} else if (rightPressed) {
    enemy1.x += 1;
    if (enemy1.x > 120) {
        rightPressed = false;
        leftPressed = true;
    }
}
var number: Number = Math.random();
if (number < 0.05){// && 
variablesGlobales.variables().coleccionEnemigos.indexOf(this) != -1) {
    trace("creation");
    var disparo: disparoEnemigo_mov = new disparoEnemigo_mov();
    this.parent.addChild(disparo);
    disparo.x=enemy1.x +115;
    disparo.y=enemy1.y +115;

    //disparo.z=50;
    trace(disparo.x + " " + disparo.y);
    }

}catch(error:Error){
removeEventListener(Event.ENTER_FRAME, fl_MoveEnemy);
}
}

In both codes, "mario" is the player character.

What I need to do is to stop the bullet creation of ""disparoEnemigo_mov" when we move to the next scene. Shouldn't the "removeEventListener(Event.ENTER_FRAME, fl_MoveEnemy)" line stop the bullets to check if there is any collision with the player?

Any help or resource will be helpful. Thank you so much!

Answer 1

It has been a while since I used AS3, but...

I believe you are expanding the hitbox of the enemy by adding bullets as children. Even when the bullets are removed from the enemy, the hitbox stays artificially expanded.

For this reason... I don't recommend adding bullets as children. Create the bullets on the same layer and keep the handle, so you can hittest them and delete them individually.

Answer 2

You're adding the bullet with this.parent.addChild(disparo); but you are not removing it when your hit event fires.

For your specific case, you would remove it after Object(this.parent).mario.y = 1000; with Object(this.parent).removeChild(this);

Answer 3

The bullet should be very small, so it's better to use hitTestPoint instead o hitTest. it is more accurate than hitTest.

See this tutorial: http://www.ilike2flash.com/2009/08/collision-detection-in-actionscript-3.html