Sets a new value to the [property@SpaceDrawer:matrix] property, as a [struct@GLib.
Variant].
If matrix is null, then an empty array is set.
If matrix is floating, it is consumed.
The [[email protected]_types_for_locations] function may be more convenient to use.
| this |
a SpaceDrawer. |
| matrix |
the new matrix value, or null. |