room_width

This variable holds the width of the current room in pixels. You can change this variable to change the width of the room at any time.

Syntax:

room_width;

Returns:

Real

Example:

if (bbox_right > room_width)
{
    x += room_width - bbox_right;
}

The above code checks to see if the current instance's sprite bounding box is greater than the width of the room, and if it is it moves the instance up.