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, 7 insertions, 4 deletions

diff --git a/vcl/source/bitmap/BitmapSymmetryCheck.cxx b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
index e5db09e463ca..9abb480864e2 100644
--- a/vcl/source/bitmap/BitmapSymmetryCheck.cxx
+++ b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
@@ -35,17 +35,19 @@ bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
 
     for (long y = 0; y < nHeightHalf; ++y)
     {
+        Scanline pScanlineRead = pReadAccess->GetScanline( y );
+        Scanline pScanlineRead2 = pReadAccess->GetScanline( nHeight - y - 1 );
         for (long x = 0; x < nWidthHalf; ++x)
         {
-            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, x))
+            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x))
             {
                 return false;
             }
-            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(y, nWidth - x - 1))
+            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
             {
                 return false;
             }
-            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, nWidth - x - 1))
+            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, nWidth - x - 1))
             {
                 return false;
             }
@@ -65,9 +67,10 @@ bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
 
     if (bHeightEven)
     {
+        Scanline pScanlineRead = pReadAccess->GetScanline( nHeightHalf );
         for (long x = 0; x < nWidthHalf; ++x)
         {
-            if (pReadAccess->GetPixel(nHeightHalf, x) != pReadAccess->GetPixel(nHeightHalf, nWidth - x - 1))
+            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
             {
                 return false;
             }