fdo#74702 New abstract function UsePolyPolygonForComplexGradient()

A new protected abstract function has been introduced only for
complex gradients. As it stands, we currently need to work out if
we should use a PolyPolygon or a Polygon because, as the comments
say:

// Determine if we output via Polygon or PolyPolygon
// For all rasteroperations other then Overpaint always use
// PolyPolygon, as we will get wrong results if we output multiple
// times on top of each other.
// Also for printers always use PolyPolygon, as not all printers
// can print polygons on top of each other.

Interestingly, the next line is either wrong or expressed badly,
because the check uses PolyPolygons when a VirtualDevice is in use:

// Also virtual devices are excluded, as some drivers are too slow.

Therefore, I've removed that comment as it seems rather misleading.

Change-Id: Ic496284cb2be8e7e2d348eae76aeeec994e1029c
Reviewed-on: https://gerrit.libreoffice.org/8802
Reviewed-by: Chris Sherlock <chris.sherlock79@gmail.com>
Tested-by: Chris Sherlock <chris.sherlock79@gmail.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/vcl/virdev.hxx b/include/vcl/virdev.hxx
index 0436b5dc7161..b2a29be735bb 100644
--- a/include/vcl/virdev.hxx
+++ b/include/vcl/virdev.hxx
@@ -140,6 +140,9 @@ public:
 private:
     SAL_DLLPRIVATE void ImplSetReferenceDevice( RefDevMode, sal_Int32 i_nDPIX, sal_Int32 i_nDPIY );
 
+protected:
+    virtual bool                UsePolyPolygonForComplexGradient() SAL_OVERRIDE;
+
 };
 
 #endif // INCLUDED_VCL_VIRDEV_HXX