Actionscript 3- Random movement on stage? Also, Boundaries? - actionscript-3

Question

I'm trying to code something where there are creatures running back and forth, up and down across the stage, and I the player, have to try to go up to them, and pick them up. There are also boundaries on stage-
The map constraints- a big rectangle box is easy enough to accomplish. I've done this.
The boundaries within the map, which are also rectangles, but instead of bouncing the player back INSIDE the rectangle, I'm trying to do the opposite- keep the player out of it.
My code for it looks like this as of now:
//Conditions that check if player/monsters are hittesting the boxes (rocks
//and stuff), then if correct, bounce them away. Following code excludes
//the monsters for simplicity.
if((mcPlayer.x - aBounceBox[b].x) < 0 && mcPlayer.y <= (aBounceBox[b].y + aBounceBox[b].height/2) && mcPlayer.y >= (aBounceBox[b].y - aBounceBox[b].height/2))
{
mcPlayer.x = aBounceBox[b].x - aBounceBox[b].width/2 - mcPlayer.width/2;
}
//Duplicate above code for right side of box here
if((mcPlayer.y - (aBounceBox[b].y + aBounceBox[b].height/2)) < 0 && (mcPlayer.x + mcPlayer.width/2) > (aBounceBox[b].x - aBounceBox[b].width/2) && (mcPlayer.x - mcPlayer.width/2) < (aBounceBox[b].x + aBounceBox[b].width/2))
{
mcPlayer.y = aBounceBox[b].y + aBounceBox[b].height/2;
}
//Duplicate above code for Upper boundary of box here
The above doesn't work very well because the code to bounce for the left and right sides of the box conflicts with the upper and lower parts of the box I'm hit-testing for. Any ideas how to do that smoothly?
Also, another problem I am having is the pathing for the monsters in the game. I'm trying to get them to do the following:
Move around "organically", or a little randomly- move a little, stop. If they encounter a boundary, they'd stop and move, elsewhere. Not concerned where to, as long as they stop moving into rocks and trees, things like that.
Not overlap as much as possible as the move around on stage.
To push each other apart if they are overlapping, although I'd like to allow them to overlap very slightly.
I'm building that code slowly, but I thought I'd just ask if anyone has any ideas on how to do that.

Answer 1

To answer your first question, you may try to implement a new class/object which indicates the xy-offset between two display objects. In order to illustrate the idea more clearly, you can have a function similar to this:
public function getOffset(source:DisplayObject, target:DisplayObject):Object {
var dx:Number = target.x - source.x;
var dy:Number = target.y - source.y;
return { x:dx, y:dy };
}
Check if the hero character is colliding with another object first by hitTestObject(displayObj) of DisplayObject class. Proceed if the result is true.
Suppose you pass in your hero character as the source object, and another obstacle as the target object,
var offset:Object = getOffset(my_hero.mc, some_obstacle.mc);
After getting the resulting offset values, compare the magnitude (absolute value) of offset.x and offset.y. The outcome can be summarized as follows:
Let absDx be Math.abs(offset.x), absDy be Math.abs(offset.y),
absDx < absDy
offset.y < 0, target is above source
offset.y > 0, target is below source
absDx > absDy
offset.x < 0, target is to the left of source
offset.x > 0, target is to the right of source
absDx == absDy
refer to one of the above cases, doesn't really matter
Then you can update the position of your hero character according to different situations.
For your second question concerning implementing a very simple AI algorithm for your creatures, you can make use of the strategy above for your creatures to verify if they collide with any other stuff or not. If they do collide, assign them other directions of movement, or even simpler, just flip the signs(+/-) of their velocities and they will travel in opposite directions.
It is easier to implement simple algorithms first. Once it is working, you can apply whatever enhancements you like afterwards. For example, change directions when reaching junctions or per 3 seconds etc.