tdf#37636 create underlines, overlines, strikeout separately

and expose a new cppcanvas::tools::createTextLinesPolyPolygon
interace to fetch them in order to fill each of them with their
own color later.

Change-Id: I26e99a9af87a69d9cb71cda6a4c03c4ba42158dc
Reviewed-on: https://gerrit.libreoffice.org/62830
Tested-by: Jenkins
Reviewed-by: Mark Hung <marklh9@gmail.com>

cppcanvas/source/mtfrenderer/mtftools.hxx

@@ -199,6 +199,14 @@ namespace cppcanvas
         ::basegfx::B2DPolyPolygon createTextLinesPolyPolygon( const ::basegfx::B2DPoint& rStartPos,
                                                               const double&              rLineWidth,
                                                               const TextLineInfo&        rTextLineInfo );
+
+        void createTextLinesPolyPolygon( const double&              rStartOffset,
+                                         const double&              rLineWidth,
+                                         const TextLineInfo&        rTextLineInfo,
+                                         ::basegfx::B2DPolyPolygon& rOverlinePolyPoly,
+                                         ::basegfx::B2DPolyPolygon& rUnderlinePolyPoly,
+                                         ::basegfx::B2DPolyPolygon& rStrikeoutPolyPoly );
+
     }
 }