Recognising enclosed shapes and their centres?

[Hype_chao]

Well, I have no idea how to get started, as I'm not all that good with any advanced features of ClickTeam products (albeit I have been using them since The Games Factory was released), and I wish to make a game capable of recognising when you have moved in a way that forms an enclosed shape, which would then create a new object in the centre of the shape made- eg. you draw a circle and a small circle/another object appears inside your shape, it doesn't need to recognise shapes, but I would really like to make it recognise an enclosed shape has been created.

Of course, my limited knowledge of the product (My shiny new copy of MMF2D!) prevents me from leaping right in and making my idea reality, so I am asking for help, where should I start, what should I use and how should I approach the problem?

I've had the idea of making a trail of objects create behind say, the mouse or another object representative, and allow you to "draw" with the limited trail of "ink" that forms. but I have no idea how to make it recognise an enclosed shape has formed.
This isn't to say I havn't tried to make my idea work, I've tried, but I don't know how to create an object in the centre of a group of objects (of the same type) after making the trail "overlap" and enclose the shape.

SO, any tips for me, any extensions I should use, specific object types? Or is this impossible?!

-Simplified explanation: How do I make a set of events that allows a program/game to recognise moving in the outline of an enclosed shape and creating an object within (prefferedly at the centre of) the formed shape?

[Dynasoft]

It's easiest if you force the user to draw the shape in one go (destroy all the ink when they let go of the mouse), and with the following conditions:
They move the mouse at least 64 (tune this number) away from where they first pressed it, otherwise you ignore the shape as being too small.
The shape is closed by having the mouse go back over the first piece of "ink".
The center of the shape is then half way between the furthest left/right up/down locations they moved the mouse while the button was held.

[DistantJ]

Ah, like NiGHTS! Umm... This is a tough one, actually, but, I guess I'd go for something like Dynasoft mentioned...

[Hype_chao]

Yes! Like NiGHTS!
That sorta way, but maybe with the mouse, or maybe not.

Dynasoft, thanks for the tip, but I want a "stream" to the ink, not a limited amount.

But then again, that way could work, but I'm unsure of how to find the extremities of the ink line like you said to, how exactly would I find the "maximum" in which they moved each direction to find the centre. Everything else I'm pretty much good with, actually I might be able to figure out how to work with a "stream" using your idea, but it might get a bit wonky (centres might be a bit off).

NEW PROBLEM: How do I measure the "extremes" of the positions of objects of the same type, like Dynasoft said I should?

[DistantJ]

I think there's an extension out there to pick the object with the highest internal value... And you could do it through that while always setting the internal value to the co-ordinate, etc...

[Hype_chao]

Yeah, that should do it. Now I need to find the Extension~ I'll check through the ones I have, though I doubt I have it.

Thanks!

[maVado]

Select Object Extension.

[Hype_chao]

Okay, I'll find that and try it out.

Ooh, I tried it, seems like what I need... But I cannot figure out how to position the newly created object at the x/y that it needs ( between the highest and lowest values).

I have the event as follows- "(created object) animation Appearing is playing" + "Select (ink) with highest alterable value A" (the x value) + "select (ink) with lowest alterable value A" (the second X value)

(NOTE: the created object was created by the collision of the ink trail with another object of itself in a previous event)

-Set X position of (created object)... and thats where I get stumped, the Select Object extension still doesn't let me differentiate between the two objects of the same type when retreiving the "A" value, as it ends up finding the average of the same object twice. (meaning the X position of the (created object) is always one O_O)

Should I make two seperate events to find the values of the positions and place them as seperate global values? Or is there any easier way?

EDIT: YAY! It sorta works... But how do I exclude the objects that are not part of the shape formed? Sorta looks strange that objects appear way off centre when the shape includes some lines that are out of place.

EDIT AGAIN: Made it as good as I can get, while allowing a constant stream rather than a fixed ink amount.
If anyone wants the working file (incase anyone else wants to do something else like this)just say so, I'll put it on here, but do take in mind the whole thing just uses the "generic diamond" picture for objects.