This function can be used to get the current scale multiplier value of the background element. You give the background element ID (which you get when you create a background element using layer_background_create() or when you use the function layer_background_get_id()), and the function will return real value that represents the scale multiplier being used to draw the sprite. Default value is 1.



Argument Description
background_element_id The unique ID value of the background element to get the information from




var lay_id = layer_get_id("Background_sky");
var back_id = layer_background_get_id(lay_id);
if layer_background_get_yscale(back_id) != -1
    layer_background_yscale(back_id, -1);

The above code will get the layer ID for the layer named "Background_sky" and then use that to get the ID of the background element on that layer. This ID is then used to check the y scale for the element and if it is not -1, it is set to -1.