# step_x var (movable atom)

Source: https://ref.dm-lang.org/atom/movable/var/step_x
Added in BYOND 490.

### Default value
> 0

This var defines the position of the atom (in pixels) relative to its tile, on the x axis. A step_x of 5 means the atom actually is shown 5 pixels east of the tile's western edge.

The atom's actual bounding box may not begin at step_x, but can be set even further in via bound_x.

Example: A 16×16 smiley face centered in a 32×32 icon should have the following bounds:

* bound_x = 8
* bound_y = 8
* bound_width = 16
* bound_height = 16

For the smiley to appear at the left edge of the tile it is standing on, it would need a step_x value of -8. A step_x value of 8 takes it all the way to the rightmost edge of the tile. Anything outside of the range -8 to 8 will have the atom straddling multiple turfs.

### See also
- [step_y var (movable atom)](https://ref.dm-lang.org/atom/movable/var/step_y.md)
- [step_size var (movable atom)](https://ref.dm-lang.org/atom/movable/var/step_size.md)
- [bound_x var (movable atom)](https://ref.dm-lang.org/atom/movable/var/bound_x.md)
- [Move proc (movable atom)](https://ref.dm-lang.org/atom/movable/proc/Move.md)
- [locs list var (movable atom)](https://ref.dm-lang.org/atom/movable/var/locs.md)
- [Pixel movement](https://ref.dm-lang.org/notes/pixel-movement.md)