use supersampling in Impress if fast opengl scaling is available

So far it's been always disabled, with the exception of the slide preview
extension.

Change-Id: Iaee6fe2d5267c9dfdc31cbf4fb90a9ac0e08e781

1 files changed, 9 insertions, 0 deletions

diff --git a/include/vcl/bitmap.hxx b/include/vcl/bitmap.hxx
index 2dbfa8161993..0fe2afa4eda1 100644
--- a/include/vcl/bitmap.hxx
+++ b/include/vcl/bitmap.hxx
@@ -560,6 +560,15 @@ public:
      */
     bool                    Scale( const double& rScaleX, const double& rScaleY, sal_uInt32 nScaleFlag = BMP_SCALE_DEFAULT );
 
+    /**
+      Returns true if bitmap scaling is considered to be fast.
+
+      Currently this returns true if OpenGL is used for scaling, otherwise false (CPU scaling is slower).
+
+      @since 4.5
+    */
+    static bool HasFastScale();
+
     // Adapt the BitCount of rNew to BitCount of lolal, including grey or color paltette
     // Can be used to create alpha/mask bitmaps after their processing in 24bit
     void                    AdaptBitCount(Bitmap& rNew) const;