Description

This read-only variable returns whether or not the instance is currently "sleeping" (true) or not (false), A "sleeping" instance is one that is not actively engaged in any physical simulation. GameMaker Studio 2 will put objects to sleep to save simulation cycles when an instance is at rest and not in collision with another instance

Syntax:

phy_sleeping;

Returns:

Boolean (or undefined if the instance is not physics enabled)

Example:

if phy_sleeping
    {
    instance_destroy();
    }

The above code checks to see if the object is being actively simulated or not and if it is not it is destroyed.