Specifies the mask threshold.
The window will be clipped to the shape of the parts of the primary layer's mask (layer opacity information) that are greater than this value.
Return Value
None (void)
Description
Sets the window region according to the primary layer's mask (layer opacity information).
This allows the window to have an irregular (non-rectangular) shape.
To ensure that the displayed primary layer does not shift from the window's size and position, you must do the following: