gboolean gtk_widget_compute_transform ( GtkWidget* widget, GtkWidget* target, graphene_matrix_t* out_transform )
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
target do not share a common ancestor. In that
out_transform gets set to the identity matrix.
To learn more about widget coordinate systems, see the coordinate system overview.
The target widget that the matrix will transform to.
The data is owned by the caller of the method.
Location to store the final transformation.
The argument will be set by the function. The data is owned by the instance.