Computes a matrix suitable to describe a transformation from
@widget's coordinate system into @target's coordinate system.
The transform can not be computed in certain cases, for example
when @widget and @target do not share a common ancestor. In that
case @out_transform gets set to the identity matrix.
Computes a matrix suitable to describe a transformation from @widget's coordinate system into @target's coordinate system.
The transform can not be computed in certain cases, for example when @widget and @target do not share a common ancestor. In that case @out_transform gets set to the identity matrix.