void pango_layout_set_spacing ( PangoLayout* layout, int spacing )
Sets the amount of spacing in Pango units between the lines of the layout.
When placing lines with spacing, Pango arranges things so that
line2.top = line1.bottom + spacing
The default value is 0.
Note: Since 1.44, Pango is using the line height (as determined
by the font) for placing lines when the line spacing factor is set
to a non-zero value with
In that case, the
spacing set with this function is ignored.
Note: for semantics that are closer to the CSS line-height