background_hspeed[0...7];
Returns: Real
By setting this variable array to a different value, you can set
the speed at which GameMaker: Studio automatically scrolls a
background for you along the horizontal plane. A positive value
will scroll from left to right, while a negative value will be
right to left and 0 stops all scrolling. if you have also enabled
horizontal tiling, either through the room editor or by using the
background_htiled
variable, then scrolling the background will make it loop
infinitely.
if background_htiled[0]
{
background_hspeed[0] = 2;
}
The above code checks background0 to see if it is tiled horizontally, and if it is it then sets the horizontal scroll speed to 2.