ds_grid_get_edgedetect

///@desc Returns a number if you check outside the ds_grid.
///@arg id
///@arg x
///@arg y

var _edge = 1;//Change this number to change what edges return as.

var _id = argument0;
var _x  = argument1;
var _y  = argument2;
var _w  = ds_grid_width(_id);
var _h  = ds_grid_height(_id);

if (_x > -1 && _x < _w && _y > -1 && _y < _h)
    {
    return(ds_grid_get(_id,_x,_y));
    }
else
    {
    return(_edge);
    }