Converts a `GskTransform` to a 2D transformation matrix.
this must be a 2D transformation. If you are not sure, use get_category >= gsk_transform_category_2d to check.
The returned values have the following layout:
``` | xx yx | | a b 0 | | xy yy | = | c d 0 | | dx dy | | tx ty 1 | ```
This function can be used to convert between a `GskTransform` and a matrix type from other 2D drawing libraries, in particular Cairo.
| this |
a 2D `GskTransform` |
| out_xx |
return location for the xx member |
| out_yx |
return location for the yx member |
| out_xy |
return location for the xy member |
| out_yy |
return location for the yy member |
| out_dx |
return location for the x0 member |
| out_dy |
return location for the y0 member |