vcl: move Bitmap::MakeMonochrome() to BitmapMonochromeFilter

Change-Id: Iefe5be4349475a4aa0138534cf6bfe87ff7df245
Reviewed-on: https://gerrit.libreoffice.org/53280
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Tomaž Vajngerl <quikee@gmail.com>

11 files changed, 191 insertions, 112 deletions

diff --git a/canvas/source/vcl/canvashelper.cxx b/canvas/source/vcl/canvashelper.cxx
index d31a45286dc3..5a0a74e389d2 100644
--- a/canvas/source/vcl/canvashelper.cxx
+++ b/canvas/source/vcl/canvashelper.cxx
@@ -46,6 +46,7 @@
 #include <vcl/bitmapaccess.hxx>
 #include <vcl/canvastools.hxx>
 #include <vcl/window.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <canvas/canvastools.hxx>
 
@@ -720,8 +721,9 @@ namespace vclcanvas
                     if( aBmpEx.IsAlpha() )
                     {
                         Bitmap aMask( aBmpEx.GetAlpha().GetBitmap() );
-                        aMask.MakeMonochrome(253);
-                        aBmpEx = BitmapEx( aBmpEx.GetBitmap(), aMask );
+                        BitmapEx aMaskEx(aMask);
+                        BitmapFilter::Filter(aMaskEx, BitmapMonochromeFilter(253));
+                        aMask = aMaskEx.GetBitmap();
                     }
                     else if( aBmpEx.IsTransparent() )
                     {
diff --git a/canvas/source/vcl/spritehelper.cxx b/canvas/source/vcl/spritehelper.cxx
index 366d0a5b9829..9424d4ec54b9 100644
--- a/canvas/source/vcl/spritehelper.cxx
+++ b/canvas/source/vcl/spritehelper.cxx
@@ -36,6 +36,7 @@
 #include <vcl/bitmapex.hxx>
 #include <vcl/canvastools.hxx>
 #include <vcl/outdev.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <canvas/canvastools.hxx>
 
@@ -153,7 +154,9 @@ namespace vclcanvas
                     {
                         OSL_FAIL("CanvasCustomSprite::redraw(): Mask bitmap is not "
                                    "monochrome (performance!)");
-                        aMask.MakeMonochrome(255);
+                        BitmapEx aMaskEx(aMask);
+                        BitmapFilter::Filter(aMaskEx, BitmapMonochromeFilter(255));
+                        aMask = aMaskEx.GetBitmap();
                     }
 #endif
 
diff --git a/include/vcl/BitmapMonochromeFilter.hxx b/include/vcl/BitmapMonochromeFilter.hxx
new file mode 100644
index 000000000000..acbcc3cc9b2c
--- /dev/null
+++ b/include/vcl/BitmapMonochromeFilter.hxx
@@ -0,0 +1,45 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#ifndef INCLUDED_INCLUDE_VCL_BITMAPMONOCHROMEFILTER_HXX
+#define INCLUDED_INCLUDE_VCL_BITMAPMONOCHROMEFILTER_HXX
+
+#include <tools/color.hxx>
+
+#include <vcl/BitmapFilter.hxx>
+
+class VCL_DLLPUBLIC BitmapMonochromeFilter : public BitmapFilter
+{
+public:
+    /** Convert to 2 color bitmap.
+
+        Converts to a 2 color indexed bitmap - note that we don't change to black
+        and white monochrome, but we pick the closest color to black and white in
+        the bitmap.
+
+        @param cThreshold
+        Luminance value that determines whether the colour should be black (or
+        closest color to black) or white (or closest color to white).
+
+     */
+    BitmapMonochromeFilter(sal_uInt8 cThreshold)
+        : mcThreshold(cThreshold)
+    {
+    }
+
+    virtual BitmapEx execute(BitmapEx const& rBitmapEx) override;
+
+private:
+    sal_uInt8 mcThreshold;
+};
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/vcl/bitmap.hxx b/include/vcl/bitmap.hxx
index 6ba6dd43378c..aa330fde9877 100644
--- a/include/vcl/bitmap.hxx
+++ b/include/vcl/bitmap.hxx
@@ -177,28 +177,14 @@ public:
      */
     bool                    Convert( BmpConversion eConversion );
 
-
-    /** Convert to 2 color bitmap.
-
-        Converts to a 2 color indexed bitmap - note that we don't change to black and white
-        monochrome, but we pick the closest color to black and white in the bitmap.
-
-        @param cThreshold
-        Luminance value that determines whether the colour should be black (or closest
-        color to black) or white (or closest color to white).
-
-        @return true conversion to monochrome bitmap was successful
-    */
-    bool                    MakeMonochrome(sal_uInt8 cThreshold);
-
     /** Apply a dither algorithm to the bitmap
 
-        This method dithers the bitmap inplace, i.e. a true color
-        bitmap is converted to a paletted bitmap, reducing the color
-        deviation by error diffusion.
+     This method dithers the bitmap inplace, i.e. a true color
+     bitmap is converted to a paletted bitmap, reducing the color
+     deviation by error diffusion.
 
-        @param nDitherFlags
-        The algorithm to be used for dithering
+     @param nDitherFlags
+     The algorithm to be used for dithering
      */
     bool                    Dither( BmpDitherFlags nDitherFlags );
 
diff --git a/vcl/Library_vcl.mk b/vcl/Library_vcl.mk
index 123d8e80fd7d..8ea16175dc55 100644
--- a/vcl/Library_vcl.mk
+++ b/vcl/Library_vcl.mk
@@ -311,6 +311,13 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/graphic/UnoGraphicTransformer \
     vcl/source/bitmap/bitmap \
     vcl/source/bitmap/bitmapfilter \
+    vcl/source/bitmap/BitmapMonochromeFilter \
+    vcl/source/bitmap/BitmapSmoothenFilter \
+    vcl/source/bitmap/BitmapLightenFilter \
+    vcl/source/bitmap/BitmapDisabledImageFilter \
+    vcl/source/bitmap/BitmapColorizeFilter \
+    vcl/source/bitmap/bitmappaint \
+    vcl/source/bitmap/BitmapGaussianSeparableBlurFilter \
     vcl/source/bitmap/BitmapSobelGreyFilter \
     vcl/source/bitmap/BitmapSolarizeFilter \
     vcl/source/bitmap/BitmapSepiaFilter \
@@ -321,13 +328,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/bitmap/BitmapConvolutionMatrixFilter \
     vcl/source/bitmap/BitmapMedianFilter \
     vcl/source/bitmap/BitmapInterpolateScaleFilter \
-    vcl/source/bitmap/BitmapLightenFilter \
-    vcl/source/bitmap/BitmapDisabledImageFilter \
-    vcl/source/bitmap/BitmapColorizeFilter \
-    vcl/source/bitmap/bitmappaint \
-    vcl/source/bitmap/BitmapGaussianSeparableBlurFilter \
     vcl/source/bitmap/BitmapSeparableUnsharpenFilter \
-    vcl/source/bitmap/BitmapSmoothenFilter \
 	vcl/source/bitmap/BitmapFastScaleFilter \
     vcl/source/bitmap/BitmapScaleSuperFilter \
     vcl/source/bitmap/BitmapScaleConvolutionFilter \
diff --git a/vcl/qa/cppunit/BitmapTest.cxx b/vcl/qa/cppunit/BitmapTest.cxx
index f835c7b78bc3..706fb1f58690 100644
--- a/vcl/qa/cppunit/BitmapTest.cxx
+++ b/vcl/qa/cppunit/BitmapTest.cxx
@@ -25,6 +25,7 @@
 #if HAVE_FEATURE_OPENGL
 #include <vcl/opengl/OpenGLHelper.hxx>
 #endif
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <BitmapSymmetryCheck.hxx>
 #include <bitmapwriteaccess.hxx>
@@ -211,7 +212,9 @@ void BitmapTest::testMonochrome()
 {
     Bitmap aBmp = createTestBitmap();
 
-    aBmp.MakeMonochrome(63);
+    BitmapEx aBmpEx(aBmp);
+    BitmapFilter::Filter(aBmpEx, BitmapMonochromeFilter(63));
+    aBmp = aBmpEx.GetBitmap();
     BitmapReadAccess aBmpReadAccess(aBmp);
 
     CPPUNIT_ASSERT_EQUAL_MESSAGE("Black pixel wrong monochrome value", BitmapColor(COL_BLACK),
diff --git a/vcl/source/bitmap/BitmapMonochromeFilter.cxx b/vcl/source/bitmap/BitmapMonochromeFilter.cxx
new file mode 100644
index 000000000000..0bdb2cd09226
--- /dev/null
+++ b/vcl/source/bitmap/BitmapMonochromeFilter.cxx
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#include <vcl/bitmap.hxx>
+#include <vcl/bitmapex.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
+#include <vcl/bitmapaccess.hxx>
+
+#include <bitmapwriteaccess.hxx>
+
+BitmapEx BitmapMonochromeFilter::execute(BitmapEx const& aBitmapEx)
+{
+    Bitmap aBitmap = aBitmapEx.GetBitmap();
+    Bitmap::ScopedReadAccess pReadAcc(aBitmap);
+    bool bRet = false;
+
+    if (pReadAcc)
+    {
+        Bitmap aNewBmp(aBitmap.GetSizePixel(), 1);
+        BitmapScopedWriteAccess pWriteAcc(aNewBmp);
+
+        if (pWriteAcc)
+        {
+            const BitmapColor aBlack(pWriteAcc->GetBestMatchingColor(COL_BLACK));
+            const BitmapColor aWhite(pWriteAcc->GetBestMatchingColor(COL_WHITE));
+            const long nWidth = pWriteAcc->Width();
+            const long nHeight = pWriteAcc->Height();
+
+            if (pReadAcc->HasPalette())
+            {
+                for (long nY = 0; nY < nHeight; nY++)
+                {
+                    Scanline pScanline = pWriteAcc->GetScanline(nY);
+                    Scanline pScanlineRead = pReadAcc->GetScanline(nY);
+                    for (long nX = 0; nX < nWidth; nX++)
+                    {
+                        const sal_uInt8 cIndex = pReadAcc->GetIndexFromData(pScanlineRead, nX);
+                        if (pReadAcc->GetPaletteColor(cIndex).GetLuminance() >= mcThreshold)
+                        {
+                            pWriteAcc->SetPixelOnData(pScanline, nX, aWhite);
+                        }
+                        else
+                        {
+                            pWriteAcc->SetPixelOnData(pScanline, nX, aBlack);
+                        }
+                    }
+                }
+            }
+            else
+            {
+                for (long nY = 0; nY < nHeight; nY++)
+                {
+                    Scanline pScanline = pWriteAcc->GetScanline(nY);
+                    Scanline pScanlineRead = pReadAcc->GetScanline(nY);
+                    for (long nX = 0; nX < nWidth; nX++)
+                    {
+                        if (pReadAcc->GetPixelFromData(pScanlineRead, nX).GetLuminance()
+                            >= mcThreshold)
+                        {
+                            pWriteAcc->SetPixelOnData(pScanline, nX, aWhite);
+                        }
+                        else
+                        {
+                            pWriteAcc->SetPixelOnData(pScanline, nX, aBlack);
+                        }
+                    }
+                }
+            }
+
+            pWriteAcc.reset();
+            bRet = true;
+        }
+
+        pReadAcc.reset();
+
+        if (bRet)
+        {
+            const MapMode aMap(aBitmap.GetPrefMapMode());
+            const Size aSize(aBitmap.GetPrefSize());
+
+            aBitmap = aNewBmp;
+
+            aBitmap.SetPrefMapMode(aMap);
+            aBitmap.SetPrefSize(aSize);
+        }
+    }
+
+    if (bRet)
+        return BitmapEx(aBitmap);
+
+    return BitmapEx();
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/bitmap/bitmap.cxx b/vcl/source/bitmap/bitmap.cxx
index b273bbfca983..23477b6e60ab 100644
--- a/vcl/source/bitmap/bitmap.cxx
+++ b/vcl/source/bitmap/bitmap.cxx
@@ -850,82 +850,6 @@ Bitmap Bitmap::CreateDisplayBitmap( OutputDevice* pDisplay )
     return aDispBmp;
 }
 
-bool Bitmap::MakeMonochrome(sal_uInt8 cThreshold)
-{
-    ScopedReadAccess pReadAcc(*this);
-    bool bRet = false;
-
-    if( pReadAcc )
-    {
-        Bitmap aNewBmp( GetSizePixel(), 1 );
-        BitmapScopedWriteAccess pWriteAcc(aNewBmp);
-
-        if( pWriteAcc )
-        {
-            const BitmapColor aBlack( pWriteAcc->GetBestMatchingColor( COL_BLACK ) );
-            const BitmapColor aWhite( pWriteAcc->GetBestMatchingColor( COL_WHITE ) );
-            const long nWidth = pWriteAcc->Width();
-            const long nHeight = pWriteAcc->Height();
-
-            if( pReadAcc->HasPalette() )
-            {
-                for( long nY = 0; nY < nHeight; nY++ )
-                {
-                    Scanline pScanline = pWriteAcc->GetScanline(nY);
-                    Scanline pScanlineRead = pReadAcc->GetScanline(nY);
-                    for( long nX = 0; nX < nWidth; nX++ )
-                    {
-                        const sal_uInt8 cIndex = pReadAcc->GetIndexFromData( pScanlineRead, nX );
-                        if( pReadAcc->GetPaletteColor( cIndex ).GetLuminance() >=
-                            cThreshold )
-                        {
-                            pWriteAcc->SetPixelOnData( pScanline, nX, aWhite );
-                        }
-                        else
-                            pWriteAcc->SetPixelOnData( pScanline, nX, aBlack );
-                    }
-                }
-            }
-            else
-            {
-                for( long nY = 0; nY < nHeight; nY++ )
-                {
-                    Scanline pScanline = pWriteAcc->GetScanline(nY);
-                    Scanline pScanlineRead = pReadAcc->GetScanline(nY);
-                    for( long nX = 0; nX < nWidth; nX++ )
-                    {
-                        if( pReadAcc->GetPixelFromData( pScanlineRead, nX ).GetLuminance() >=
-                            cThreshold )
-                        {
-                            pWriteAcc->SetPixelOnData( pScanline, nX, aWhite );
-                        }
-                        else
-                            pWriteAcc->SetPixelOnData( pScanline, nX, aBlack );
-                    }
-                }
-            }
-
-            pWriteAcc.reset();
-            bRet = true;
-        }
-
-        pReadAcc.reset();
-
-        if( bRet )
-        {
-            const MapMode aMap( maPrefMapMode );
-            const Size aSize( maPrefSize );
-
-            *this = aNewBmp;
-
-            maPrefMapMode = aMap;
-            maPrefSize = aSize;
-        }
-    }
-
-    return bRet;
-}
-
 bool Bitmap::GetSystemData( BitmapSystemData& rData ) const
 {
     bool bRet = false;
diff --git a/vcl/source/gdi/bitmap3.cxx b/vcl/source/gdi/bitmap3.cxx
index 8503db8fc2ca..e178a0c845b3 100644
--- a/vcl/source/gdi/bitmap3.cxx
+++ b/vcl/source/gdi/bitmap3.cxx
@@ -27,6 +27,7 @@
 #if HAVE_FEATURE_OPENGL
 #include <vcl/opengl/OpenGLHelper.hxx>
 #endif
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <impoctree.hxx>
 #include <BitmapScaleSuperFilter.hxx>
@@ -245,7 +246,11 @@ bool Bitmap::Convert( BmpConversion eConversion )
     switch( eConversion )
     {
         case BmpConversion::N1BitThreshold:
-            bRet = MakeMonochrome(128);
+        {
+            BitmapEx aBmpEx(*this);
+            bRet = BitmapFilter::Filter(aBmpEx, BitmapMonochromeFilter(128));
+            *this = aBmpEx.GetBitmap();
+        }
         break;
 
         case BmpConversion::N4BitGreys:
diff --git a/vcl/source/gdi/bitmapex.cxx b/vcl/source/gdi/bitmapex.cxx
index 4d31dbb1fa0a..c81b8b0fd446 100644
--- a/vcl/source/gdi/bitmapex.cxx
+++ b/vcl/source/gdi/bitmapex.cxx
@@ -34,6 +34,7 @@
 #include <vcl/bitmapaccess.hxx>
 #include <vcl/virdev.hxx>
 #include <vcl/settings.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 // BitmapEx::Create
 #include <salbmp.hxx>
@@ -125,7 +126,9 @@ BitmapEx::BitmapEx( const Bitmap& rBmp, const Bitmap& rMask ) :
     if( !!maMask && maMask.GetBitCount() != 1 )
     {
         SAL_WARN( "vcl", "BitmapEx: forced mask to monochrome");
-        maMask.MakeMonochrome(255);
+        BitmapEx aMaskEx(maMask);
+        BitmapFilter::Filter(aMaskEx, BitmapMonochromeFilter(255));
+        maMask = aMaskEx.GetBitmap();
     }
 
     if (!!maBitmap && !!maMask && maBitmap.GetSizePixel() != maMask.GetSizePixel())
@@ -249,8 +252,13 @@ Bitmap BitmapEx::GetMask() const
 {
     Bitmap aRet( maMask );
 
-    if( IsAlpha() )
-        aRet.MakeMonochrome(255);
+    if (IsAlpha())
+    {
+
+        BitmapEx aMaskEx(aRet);
+        BitmapFilter::Filter(aMaskEx, BitmapMonochromeFilter(255));
+        aRet = aMaskEx.GetBitmap();
+    }
 
     return aRet;
 }
diff --git a/vcl/source/outdev/bitmap.cxx b/vcl/source/outdev/bitmap.cxx
index e924a1f35f58..4108bc6f2cf8 100644
--- a/vcl/source/outdev/bitmap.cxx
+++ b/vcl/source/outdev/bitmap.cxx
@@ -32,6 +32,7 @@
 #include <vcl/virdev.hxx>
 #include <vcl/image.hxx>
 #include <vcl/window.hxx>
+#include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <bmpfast.hxx>
 #include <salgdi.hxx>
@@ -327,9 +328,9 @@ void OutputDevice::DrawBitmapEx( const Point& rDestPt, const Size& rDestSize,
                     // DRAWMODE_BLACK/WHITEBITMAP requires monochrome
                     // output, having alpha-induced grey levels is not
                     // acceptable.
-                    Bitmap aMask( aBmpEx.GetAlpha().GetBitmap() );
-                    aMask.MakeMonochrome(129);
-                    aBmpEx = BitmapEx( aColorBmp, aMask );
+                    BitmapEx aMaskEx(aBmpEx.GetAlpha().GetBitmap());
+                    BitmapFilter::Filter(aMaskEx, BitmapMonochromeFilter(129));
+                    aBmpEx = BitmapEx(aColorBmp, aMaskEx.GetBitmap());
                 }
                 else
                 {