[AS3]Collision with walls using hitTestObject

Question

So I am currently trying to do a game which is almost like a maze. The problem is with the wall collision, once the character hits a wall, I can't get him out anymore, he gets "stuck" no matter what direction I try to take him after the collision. One of the solutions I was thinking would be to whenever the character hits the wall, to "back him up", so that there is no more collision detected. However, when I do that, he goes through the wall in a strange way. Here is my code so you guys can have an idea of what I'm doing:

function keyPressed(event:KeyboardEvent):void
{

    if (event.keyCode == Keyboard.LEFT)
    {
       leftArrow = true;
       if(char.hitTestObject(test))
       {
           leftHit= true;
       } else { 
           leftHit = false;
       }
    }
    if (event.keyCode == Keyboard.RIGHT)
    {
       rightArrow = true;
       if(char.hitTestObject(test))
       {
           rightHit= true;
       } else { 
           rightHit = false;
       }
    }


}

function keyReleased(event:KeyboardEvent):void 
{

    if (event.keyCode == Keyboard.LEFT) 
    {
        leftArrow = false;
    }
    if (event.keyCode == Keyboard.RIGHT)
    {
       rightArrow = false;
    }

}

function walking(event:Event):void {
    if (rightArrow) {
        if(rightHit)
            char.x -= speed;
        else
            char.x += speed;    
    }

    if (leftArrow) {
        if(leftHit)
            char.x += speed;
        else
            char.x -= speed;
    }
}

A big part of this code I actually got from another person asking the same question. Even doing what was suggested in the other topic, the problem still remains. Thank you very much for any help!

Is your speed value consistent from frame to frame ? Or is it based on the time passed since the last frame ? — prototypical
it's consistent frame to frame. It's basically a constant and I left it's value as 10. — theJuls

theJuls theJuls · Accepted Answer · 2014-05-20T15:08:16

As requested, here is my solution:

 if (rightArrow) {
                if (!test.hitTestPoint(MovieClip(root).char.x+speed, MovieClip(root).char.y, true))
                {
                    MovieClip(root).char.x += speed;    
                    x = x-speed; //moving the background
                }
            }

            if (leftArrow) {
                if (!test.hitTestPoint(MovieClip(root).char.x-speed, MovieClip(root).char.y, true))
                {
                    MovieClip(root).char.x -= speed;
                    x = x+speed; //moving the background
                }
            }
            if (upArrow) {
                if (!test.hitTestPoint(MovieClip(root).char.x, MovieClip(root).char.y-speed, true))
                {
                    MovieClip(root).char.y -= speed;    
                    y = y+speed; //moving the background
                }
            }

            if (downArrow) {
                if (!test.hitTestPoint(MovieClip(root).char.x, MovieClip(root).char.y+speed, true))
                {
                    MovieClip(root).char.y += speed;
                    y = y-speed; //moving the background
                }
            }

It's been a while so some of this stuff I really don't remember, but from what I can see, I check if adding the speed of my character will make it become collided with the wall. If that happens, I do not move the character even if I do seemingly have enough space. I think that is pretty much it.

Hope it helps.

[AS3]Collision with walls using hitTestObject

1 Answers