remove code duplication for BitmapReadAccess pixel functions

Change-Id: Ib243fea4276cfb86b4fdff8d0c84cea7c4523d82
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/97487
Tested-by: Jenkins
Reviewed-by: Luboš Luňák <l.lunak@collabora.com>

2 files changed, 78 insertions, 125 deletions

diff --git a/vcl/source/gdi/bmpacc.cxx b/vcl/source/gdi/bmpacc.cxx
index 70500a8b8723..8b7760772880 100644
--- a/vcl/source/gdi/bmpacc.cxx
+++ b/vcl/source/gdi/bmpacc.cxx
@@ -95,9 +95,10 @@ BitmapReadAccess::BitmapReadAccess( Bitmap& rBitmap, BitmapAccessMode nMode ) :
 
     maColorMask = mpBuffer->maColorMask;
 
-    bool bOk = ImplSetAccessPointers(RemoveScanline(mpBuffer->mnFormat));
+    mFncGetPixel = GetPixelFunction(mpBuffer->mnFormat);
+    mFncSetPixel = SetPixelFunction(mpBuffer->mnFormat);
 
-    if (!bOk)
+    if (!mFncGetPixel || !mFncSetPixel)
     {
         xImpBmp->ReleaseBuffer( mpBuffer, mnAccessMode );
         mpBuffer = nullptr;
@@ -117,129 +118,101 @@ namespace
     }
 }
 
-bool BitmapReadAccess::ImplSetAccessPointers( ScanlineFormat nFormat )
+FncGetPixel BitmapReadAccess::GetPixelFunction( ScanlineFormat nFormat )
 {
-    bool bRet = true;
+    switch( RemoveScanline( nFormat ))
+    {
+        case ScanlineFormat::N1BitMsbPal:
+            return GetPixelForN1BitMsbPal;
+        case ScanlineFormat::N1BitLsbPal:
+            return GetPixelForN1BitLsbPal;
+        case ScanlineFormat::N4BitMsnPal:
+            return GetPixelForN4BitMsnPal;
+        case ScanlineFormat::N4BitLsnPal:
+            return GetPixelForN4BitLsnPal;
+        case ScanlineFormat::N8BitPal:
+            return GetPixelForN8BitPal;
+        case ScanlineFormat::N8BitTcMask:
+            return GetPixelForN8BitTcMask;
+        case ScanlineFormat::N24BitTcBgr:
+            return GetPixelForN24BitTcBgr;
+        case ScanlineFormat::N24BitTcRgb:
+            return GetPixelForN24BitTcRgb;
+        case ScanlineFormat::N32BitTcAbgr:
+            if (Bitmap32IsPreMultipled())
+                return GetPixelForN32BitTcAbgr;
+            else
+                return GetPixelForN32BitTcXbgr;
+        case ScanlineFormat::N32BitTcArgb:
+            if (Bitmap32IsPreMultipled())
+                return GetPixelForN32BitTcArgb;
+            else
+                return GetPixelForN32BitTcXrgb;
+        case ScanlineFormat::N32BitTcBgra:
+            if (Bitmap32IsPreMultipled())
+                return GetPixelForN32BitTcBgra;
+            else
+                return GetPixelForN32BitTcBgrx;
+        case ScanlineFormat::N32BitTcRgba:
+            if (Bitmap32IsPreMultipled())
+                return GetPixelForN32BitTcRgba;
+            else
+                return GetPixelForN32BitTcRgbx;
+        case ScanlineFormat::N32BitTcMask:
+            return GetPixelForN32BitTcMask;
+
+        default:
+            return nullptr;
+    }
+}
 
-    switch( nFormat )
+FncSetPixel BitmapReadAccess::SetPixelFunction( ScanlineFormat nFormat )
+{
+    switch( RemoveScanline( nFormat ))
     {
         case ScanlineFormat::N1BitMsbPal:
-        {
-            mFncGetPixel = GetPixelForN1BitMsbPal;
-            mFncSetPixel = SetPixelForN1BitMsbPal;
-        }
-        break;
+            return SetPixelForN1BitMsbPal;
         case ScanlineFormat::N1BitLsbPal:
-        {
-            mFncGetPixel = GetPixelForN1BitLsbPal;
-            mFncSetPixel = SetPixelForN1BitLsbPal;
-        }
-        break;
+            return SetPixelForN1BitLsbPal;
         case ScanlineFormat::N4BitMsnPal:
-        {
-            mFncGetPixel = GetPixelForN4BitMsnPal;
-            mFncSetPixel = SetPixelForN4BitMsnPal;
-        }
-        break;
+            return SetPixelForN4BitMsnPal;
         case ScanlineFormat::N4BitLsnPal:
-        {
-            mFncGetPixel = GetPixelForN4BitLsnPal;
-            mFncSetPixel = SetPixelForN4BitLsnPal;
-        }
-        break;
+            return SetPixelForN4BitLsnPal;
         case ScanlineFormat::N8BitPal:
-        {
-            mFncGetPixel = GetPixelForN8BitPal;
-            mFncSetPixel = SetPixelForN8BitPal;
-        }
-        break;
+            return SetPixelForN8BitPal;
         case ScanlineFormat::N8BitTcMask:
-        {
-            mFncGetPixel = GetPixelForN8BitTcMask;
-            mFncSetPixel = SetPixelForN8BitTcMask;
-        }
-        break;
+            return SetPixelForN8BitTcMask;
         case ScanlineFormat::N24BitTcBgr:
-        {
-            mFncGetPixel = GetPixelForN24BitTcBgr;
-            mFncSetPixel = SetPixelForN24BitTcBgr;
-        }
-        break;
+            return SetPixelForN24BitTcBgr;
         case ScanlineFormat::N24BitTcRgb:
-        {
-            mFncGetPixel = GetPixelForN24BitTcRgb;
-            mFncSetPixel = SetPixelForN24BitTcRgb;
-        }
-        break;
+            return SetPixelForN24BitTcRgb;
         case ScanlineFormat::N32BitTcAbgr:
-        {
             if (Bitmap32IsPreMultipled())
-            {
-                mFncGetPixel = GetPixelForN32BitTcAbgr;
-                mFncSetPixel = SetPixelForN32BitTcAbgr;
-            }
+                return SetPixelForN32BitTcAbgr;
             else
-            {
-                mFncGetPixel = GetPixelForN32BitTcXbgr;
-                mFncSetPixel = SetPixelForN32BitTcXbgr;
-            }
-        }
-        break;
+                return SetPixelForN32BitTcXbgr;
         case ScanlineFormat::N32BitTcArgb:
-        {
             if (Bitmap32IsPreMultipled())
-            {
-                mFncGetPixel = GetPixelForN32BitTcArgb;
-                mFncSetPixel = SetPixelForN32BitTcArgb;
-            }
+                return SetPixelForN32BitTcArgb;
             else
-            {
-                mFncGetPixel = GetPixelForN32BitTcXrgb;
-                mFncSetPixel = SetPixelForN32BitTcXrgb;
-            }
-        }
-        break;
+                return SetPixelForN32BitTcXrgb;
         case ScanlineFormat::N32BitTcBgra:
-        {
             if (Bitmap32IsPreMultipled())
-            {
-                mFncGetPixel = GetPixelForN32BitTcBgra;
-                mFncSetPixel = SetPixelForN32BitTcBgra;
-            }
+                return SetPixelForN32BitTcBgra;
             else
-            {
-                mFncGetPixel = GetPixelForN32BitTcBgrx;
-                mFncSetPixel = SetPixelForN32BitTcBgrx;
-            }
-        }
-        break;
+                return SetPixelForN32BitTcBgrx;
         case ScanlineFormat::N32BitTcRgba:
-        {
             if (Bitmap32IsPreMultipled())
-            {
-                mFncGetPixel = GetPixelForN32BitTcRgba;
-                mFncSetPixel = SetPixelForN32BitTcRgba;
-            }
+                return SetPixelForN32BitTcRgba;
             else
-            {
-                mFncGetPixel = GetPixelForN32BitTcRgbx;
-                mFncSetPixel = SetPixelForN32BitTcRgbx;
-            }
-        }
-        break;
+                return SetPixelForN32BitTcRgbx;
         case ScanlineFormat::N32BitTcMask:
-        {
-            mFncGetPixel = GetPixelForN32BitTcMask;
-            mFncSetPixel = SetPixelForN32BitTcMask;
-        }
+            return SetPixelForN32BitTcMask;
         break;
 
         default:
-            bRet = false;
-        break;
+            return nullptr;
     }
-
-    return bRet;
 }
 
 BitmapColor BitmapReadAccess::GetInterpolatedColorWithFallback( double fY, double fX, const BitmapColor& rFallback ) const
diff --git a/vcl/source/gdi/salmisc.cxx b/vcl/source/gdi/salmisc.cxx
index a6a5e36279a2..6f790f727ca6 100644
--- a/vcl/source/gdi/salmisc.cxx
+++ b/vcl/source/gdi/salmisc.cxx
@@ -26,11 +26,6 @@
 #include <tools/helpers.hxx>
 #include <memory>
 
-#define IMPL_CASE_GET_FORMAT( Format )                          \
-case( ScanlineFormat::Format ):                                 \
-    pFncGetPixel = BitmapReadAccess::GetPixelFor##Format;       \
-break
-
 #define IMPL_CASE_SET_FORMAT( Format, BitCount )                \
 case( ScanlineFormat::Format ):                                 \
 {                                                               \
@@ -270,29 +265,14 @@ std::unique_ptr<BitmapBuffer> StretchAndConvert(
     std::unique_ptr<BitmapBuffer> pDstBuffer(new BitmapBuffer);
 
     // set function for getting pixels
-    switch( RemoveScanline( rSrcBuffer.mnFormat ) )
-    {
-        IMPL_CASE_GET_FORMAT( N1BitMsbPal );
-        IMPL_CASE_GET_FORMAT( N1BitLsbPal );
-        IMPL_CASE_GET_FORMAT( N4BitMsnPal );
-        IMPL_CASE_GET_FORMAT( N4BitLsnPal );
-        IMPL_CASE_GET_FORMAT( N8BitPal );
-        IMPL_CASE_GET_FORMAT( N8BitTcMask );
-        IMPL_CASE_GET_FORMAT( N24BitTcBgr );
-        IMPL_CASE_GET_FORMAT( N24BitTcRgb );
-        IMPL_CASE_GET_FORMAT( N32BitTcAbgr );
-        IMPL_CASE_GET_FORMAT( N32BitTcArgb );
-        IMPL_CASE_GET_FORMAT( N32BitTcBgra );
-        IMPL_CASE_GET_FORMAT( N32BitTcRgba );
-        IMPL_CASE_GET_FORMAT( N32BitTcMask );
-
-        default:
-            // should never come here
-            // initialize pFncGetPixel to something valid that is
-            // least likely to crash
-            pFncGetPixel = BitmapReadAccess::GetPixelForN1BitMsbPal;
-            OSL_FAIL( "unknown read format" );
-        break;
+    pFncGetPixel = BitmapReadAccess::GetPixelFunction( rSrcBuffer.mnFormat );
+    if( !pFncGetPixel )
+    {
+        // should never come here
+        // initialize pFncGetPixel to something valid that is
+        // least likely to crash
+        pFncGetPixel = BitmapReadAccess::GetPixelForN1BitMsbPal;
+        OSL_FAIL( "unknown read format" );
     }
 
     // set function for setting pixels