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, 2 deletions

diff --git a/include/vcl/window.hxx b/include/vcl/window.hxx
index 5751489fe1c7..a527a8f2be76 100644
--- a/include/vcl/window.hxx
+++ b/include/vcl/window.hxx
@@ -579,8 +579,9 @@ protected:
     virtual sal_uInt16 getDefaultAccessibleRole() const;
     virtual OUString getDefaultAccessibleName() const;
 
-    virtual void               CopyAreaFinal( SalTwoRect& aPosAry, sal_uInt32 nFlags) SAL_OVERRIDE;
-    virtual void               ClipToPaintRegion( Rectangle& rDstRect ) SAL_OVERRIDE;
+    virtual void                CopyAreaFinal( SalTwoRect& aPosAry, sal_uInt32 nFlags) SAL_OVERRIDE;
+    virtual void                ClipToPaintRegion( Rectangle& rDstRect ) SAL_OVERRIDE;
+    virtual bool                UsePolyPolygonForComplexGradient() SAL_OVERRIDE;
 
 public:
     bool HasMirroredGraphics() const SAL_OVERRIDE;