Spatial data in rails on postgresql without "BIG adapter"?

(Frenchy, sorry)
Hi everyone, i'm working on a web browser based game. I need to use
some postgresql special type such as point, path and line.
ActiveRecord caused me some troubles to migrate but now it's ok for
creating/migrating the database and querying the tables. BUT! Every
special type select are returned me as String...

To begin i tried to use a simple position "point" column. I tried some
few things like:

@first_character = Character.select("position[0] as x, position[1] as
y").first
@first_character.x returns me the good x value
@first_character.y return me a nil value...

OR:

@first_character = Character.select("position[1] as y, position[0] as
x").first
@first_character.y returns me the good y value
@first_character.x return me a nil value...

Why?!!

I know i should use an adapter, but: i really don't need PostGIS on my
database, i just use simples types and functions proposed by
postgresql native.

Regards.

What data type is the position column in your database?

position column is Point.

For now i'm using a personnalized point class which i load into
character model:
composed_of :position, :class_name => "Point", :mapping => %w(position
point)

It work properly, but i'm affraid when i'll need to use some pgsql
geometric functions/operator it return me errors...