Question

I am trying to place an object at my players current position but when i move away the object sticks to my player. I kind of know why it sticking to my player but i cant think of any other code to use.

Hero is my player that i move around the screen.

Thanks Lochy

var trap1:trap = new trap();

function keydown(event:KeyboardEvent) :void {


    if(event.keyCode ==32)
    addChild(trap1);
    trap1.x = hero.x;
    trap1.y = hero.y;

Answer 1

There are several ways to accomplish this task. There is basically a detail you have to know. In Flash, the display list is responsible for managing elements on the screen. The DisplayObject and DisplayObjectContainer classes provide the API to access and manipulate the display list.

A naive approach would be

function placeAbove(d1:DisplayObject, d2:DisplayObject):void
{
  if (!d1 || !d2) return;

  d1.x = d2.x;
  d1.y = d2.y;
}

But when both DisplayObjects have different parents, the DisplayObjects are not part of te same coordinate system, so this little method won’t work. I coded a small example:

package
{

  import flash.display.DisplayObject;
  import flash.display.DisplayObjectContainer;
  import flash.display.Sprite;
  import flash.geom.Point;

  public class Points extends Sprite
  {
    public function Points()
    {
      const child1:Sprite = createSquare(50, 50, 0xFF0000, .5)
          , child2:Sprite = createSquare(100, 100, 0x0000FF, .5)
          , container1:Sprite = new Sprite()
          , container2:Sprite = new Sprite();

      DisplayObjectContainer(placeRandomly(addChild(container1))).addChild(child1);
      DisplayObjectContainer(placeRandomly(addChild(container2))).addChild(child2);

      placeAbove(child1, child2);
    }

    private function createSquare(width:Number, height:Number, color:uint = 0, alpha:Number = 1):Sprite
    {
      const sprite:Sprite = new Sprite();
      sprite.graphics.beginFill(color, alpha);
      sprite.graphics.drawRect(0, 0, width, height);
      sprite.graphics.endFill();

      return sprite;
    }

    private function placeAbove(child1:Sprite, child2:Sprite):void
    {
      const point:Point = child2.localToGlobal(new Point(0, 0))
              , point2:Point = child1.globalToLocal(point);

      child1.x = point2.x;
      child1.y = point2.y;
    }

    private function placeRandomly(displayObject:DisplayObject):DisplayObject
    {
      displayObject.x = Math.random() * 100;
      displayObject.y = Math.random() * 100;

      return displayObject;
    }
  }
}

The Application generate 2 squares and adds it into different parents. The containers (parents) are placed randomly on the screen and so are the two child display objects. The placeAbove method does all the magic. It calculates the position from the second display object globally and the maps it to the first display objects target local position within the parent’s coordinate system.

Ii hope it helps.