Note: This feature is available in Web Workers.
The DOMPointReadOnly interface's w property holds the point's perspective value, w, for a read-only point in space.
If your script needs to be able to change the value of this property, you should instead use the DOMPoint object.
A double-precision floating-point value indicating the w perspective value for the point. This value is unrestricted, meaning that it is allowed to be infinite or invalid (that is, its value may be NaN or ±Infinity). The default is 1.0.