Obtains the coordinates where the scale will draw the `PangoLayout` representing the text in the scale.
Remember when using the `PangoLayout` function you need to convert to and from pixels using `PANGO_PIXELS()` or `PANGO_SCALE`.
If the [property@GtkScale:draw-value] property is false, the return values are undefined.
| this |
a `GtkScale` |
| x |
location to store X offset of layout |
| y |
location to store Y offset of layout |