GM: x

From GMpedia.org Wiki

x
Type:	variable
Globalism:	Local
Editable:	Yes

The x variable is a local variable that represents the x position of an object in a room.

There is an x-axis and an y-axis on the image. The number on the x-axis indicates where the object is relative to the point (0,0) in horizontal direction.

The gray area indicates the upper left corner of a room in Game Maker. When editing a room, the white areas are never visible.