background_alpha[0...7]
Returns: Real
This variable array returns the alpha (transparency) value of any one of the 8 backgrounds (numbered form 0 - 7 within the array) of the current room. This value can be anywhere between 0 and 1, where 0
indicates that the background is completely transparent and 1 (the default value) indicates that the background is completely opaque.
if background_alpha[0] <1 background_alpha[0] = 1;
The above code checks the alpha value for background0 and if it is less than 1, it sets it to 1.