use generic names rather than specific algorithm names when scaling

The Lanczos scaling is of very good quality, but it's rather slow,
which can be very noticeable with large images, so it's not a very
good default for everything. And in general, it's not good to refer
to a specific algorithm when all one usually wants is fast/default/best.

Some of these changes are a bit of a guess between default/best,
but the general logic is that best should be used only for images
that won't be large or where the possible waiting does not matter.

Change-Id: I53765507ecb7ed167890f6dd05e73fe53ffd0231

5 files changed, 12 insertions, 7 deletions

diff --git a/vcl/inc/vcl/bitmap.hxx b/vcl/inc/vcl/bitmap.hxx
index 2fbe1848c427..06f2bf1b7ae0 100644
--- a/vcl/inc/vcl/bitmap.hxx
+++ b/vcl/inc/vcl/bitmap.hxx
@@ -54,6 +54,11 @@
 #define BMP_SCALE_BILINEAR          0x00000005UL
 #define BMP_SCALE_BOX               0x00000006UL
 
+// Aliases, try to use these two (or BMP_SCALE_FAST/BMP_SCALE_NONE),
+// use a specific algorithm only if you really need to.
+#define BMP_SCALE_BEST              BMP_SCALE_LANCZOS
+#define BMP_SCALE_DEFAULT           BMP_SCALE_BOX
+
 // -----------------------------------------------------------------------------
 
 #define BMP_DITHER_NONE             0x00000000UL
@@ -630,7 +635,7 @@ public:
         @return sal_True, if the operation was completed successfully.
      */
     sal_Bool                    Scale( const Size& rNewSize,
-                                   sal_uLong nScaleFlag = BMP_SCALE_LANCZOS );
+                                   sal_uLong nScaleFlag = BMP_SCALE_DEFAULT );
 
     /** Scale the bitmap
 
@@ -643,7 +648,7 @@ public:
         @return sal_True, if the operation was completed successfully.
      */
     sal_Bool                    Scale( const double& rScaleX, const double& rScaleY,
-                                   sal_uLong nScaleFlag = BMP_SCALE_LANCZOS );
+                                   sal_uLong nScaleFlag = BMP_SCALE_DEFAULT );
 
     /** Rotate bitmap by the specified angle
 
diff --git a/vcl/inc/vcl/bitmapex.hxx b/vcl/inc/vcl/bitmapex.hxx
index f1f46d3aec35..845981aa5c1e 100644
--- a/vcl/inc/vcl/bitmapex.hxx
+++ b/vcl/inc/vcl/bitmapex.hxx
@@ -254,7 +254,7 @@ public:
 
         @return sal_True, if the operation was completed successfully.
      */
-    sal_Bool                Scale( const Size& rNewSize, sal_uLong nScaleFlag = BMP_SCALE_LANCZOS );
+    sal_Bool                Scale( const Size& rNewSize, sal_uLong nScaleFlag = BMP_SCALE_DEFAULT );
 
     /** Scale the bitmap
 
@@ -266,7 +266,7 @@ public:
 
         @return sal_True, if the operation was completed successfully.
      */
-    sal_Bool                Scale( const double& rScaleX, const double& rScaleY, sal_uLong nScaleFlag = BMP_SCALE_LANCZOS );
+    sal_Bool                Scale( const double& rScaleX, const double& rScaleY, sal_uLong nScaleFlag = BMP_SCALE_DEFAULT );
 
     /** Rotate bitmap by the specified angle
 
diff --git a/vcl/source/gdi/bitmapex.cxx b/vcl/source/gdi/bitmapex.cxx
index 72c91e43003f..d1d42629f7b1 100644
--- a/vcl/source/gdi/bitmapex.cxx
+++ b/vcl/source/gdi/bitmapex.cxx
@@ -754,7 +754,7 @@ BitmapEx BitmapEx:: AutoScaleBitmap(BitmapEx & aBitmap, const long aStandardSize
         }
 
         aScaledSize = Size( imgNewWidth, imgNewHeight );
-        aRet.Scale( aScaledSize, BMP_SCALE_LANCZOS );
+        aRet.Scale( aScaledSize, BMP_SCALE_BEST );
     }
     else
     {
diff --git a/vcl/source/gdi/pdfwriter_impl2.cxx b/vcl/source/gdi/pdfwriter_impl2.cxx
index 3fc7fac69b14..d7998c9b1264 100644
--- a/vcl/source/gdi/pdfwriter_impl2.cxx
+++ b/vcl/source/gdi/pdfwriter_impl2.cxx
@@ -139,7 +139,7 @@ void PDFWriterImpl::implWriteBitmapEx( const Point& i_rPoint, const Size& i_rSiz
                     aNewBmpSize.Height() = FRound( fMaxPixelX / fBmpWH);
                 }
                 if( aNewBmpSize.Width() && aNewBmpSize.Height() )
-                    aBitmapEx.Scale( aNewBmpSize, BMP_SCALE_LANCZOS );
+                    aBitmapEx.Scale( aNewBmpSize, BMP_SCALE_BEST );
                 else
                     aBitmapEx.SetEmpty();
             }
diff --git a/vcl/source/helper/canvasbitmap.cxx b/vcl/source/helper/canvasbitmap.cxx
index 854dea4dfaac..b2f145de07c5 100644
--- a/vcl/source/helper/canvasbitmap.cxx
+++ b/vcl/source/helper/canvasbitmap.cxx
@@ -460,7 +460,7 @@ uno::Reference< rendering::XBitmap > SAL_CALL VclCanvasBitmap::getScaledBitmap(
     SolarMutexGuard aGuard;
 
     BitmapEx aNewBmp( m_aBitmap );
-    aNewBmp.Scale( sizeFromRealSize2D( newSize ), beFast ? BMP_SCALE_FAST : BMP_SCALE_LANCZOS );
+    aNewBmp.Scale( sizeFromRealSize2D( newSize ), beFast ? BMP_SCALE_FAST : BMP_SCALE_DEFAULT );
     return uno::Reference<rendering::XBitmap>( new VclCanvasBitmap( aNewBmp ) );
 }