use scanline when reading pixel data

extracts code from the innermost part of fairly hot loops

And add a GetIndexFromData method to make the call sites a little easier
to read.

Change-Id: I4ce5c5a687ecdb6982562a0aafce8513d86f9107
Reviewed-on: https://gerrit.libreoffice.org/49337
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/vcl/bitmapaccess.hxx b/include/vcl/bitmapaccess.hxx
index 5ae64f8193cc..37eaef6dcda9 100644
--- a/include/vcl/bitmapaccess.hxx
+++ b/include/vcl/bitmapaccess.hxx
@@ -189,6 +189,11 @@ public:
         return mFncGetPixel( pData, nX, maColorMask );
     }
 
+    sal_uInt8 GetIndexFromData(const sal_uInt8* pData, long nX) const
+    {
+        return GetPixelFromData( pData, nX ).GetIndex();
+    }
+
     void SetPixelOnData(sal_uInt8* pData, long nX, const BitmapColor& rBitmapColor)
     {
         assert(pData && "Access is not valid!");