[Libreoffice-commits] core.git: Branch 'private/tvajngerl/staging' - 3 commits - include/vcl Repository.mk vcl/backendtest vcl/Executable_benchmark.mk vcl/inc vcl/Library_vcl.mk vcl/Module_vcl.mk vcl/qa vcl/source

Tomaž Vajngerl (via logerrit) logerrit at kemper.freedesktop.org
Sat Aug 29 13:24:40 UTC 2020


 Repository.mk                                |    1 
 include/vcl/bitmap.hxx                       |    3 
 vcl/Executable_benchmark.mk                  |   56 +
 vcl/Library_vcl.mk                           |    2 
 vcl/Module_vcl.mk                            |    1 
 vcl/backendtest/Benchmark.cxx                |  302 ++++++
 vcl/inc/BitmapComboScaleFilter.hxx           |   52 +
 vcl/inc/BitmapSymmetryCheck.hxx              |   16 
 vcl/inc/bitmap/ScanlineHalfScaler.hxx        |   91 +
 vcl/qa/cppunit/BitmapFilterTest.cxx          |    4 
 vcl/qa/cppunit/BitmapScaleTest.cxx           |  143 ++
 vcl/source/bitmap/BitmapComboScaleFilter.cxx |  367 +++++++
 vcl/source/bitmap/BitmapSymmetryCheck.cxx    |   77 -
 vcl/source/bitmap/ScanlineHalfScaler.cxx     | 1359 +++++++++++++++++++++++++++
 vcl/source/gdi/bitmap3.cxx                   |    4 
 15 files changed, 2408 insertions(+), 70 deletions(-)

New commits:
commit 31f83f8b36c40efc13597048dfd6733360f7b25d
Author:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
AuthorDate: Sat Aug 29 15:22:03 2020 +0200
Commit:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
CommitDate: Sat Aug 29 15:22:03 2020 +0200

    Benchmark
    
    Change-Id: I22e0ac54380e2d22606e7b1fd453bed843523a29

diff --git a/Repository.mk b/Repository.mk
index dbb628f2a6b3..c607831919f5 100644
--- a/Repository.mk
+++ b/Repository.mk
@@ -74,6 +74,7 @@ $(eval $(call gb_Helper_register_executables,NONE, \
 	tiledrendering \
     mtfdemo \
     visualbackendtest \
+    benchmark \
 	$(if $(and $(ENABLE_GTK3), $(filter LINUX %BSD SOLARIS,$(OS))), gtktiledviewer) \
 ))
 
diff --git a/vcl/Executable_benchmark.mk b/vcl/Executable_benchmark.mk
new file mode 100644
index 000000000000..c72039c13f7b
--- /dev/null
+++ b/vcl/Executable_benchmark.mk
@@ -0,0 +1,56 @@
+# -*- Mode: makefile-gmake; tab-width: 4; indent-tabs-mode: t -*-
+#
+#
+# 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/.
+#
+
+$(eval $(call gb_Executable_Executable,benchmark))
+
+$(eval $(call gb_Executable_use_api,benchmark,\
+    offapi \
+    udkapi \
+))
+
+$(eval $(call gb_Executable_use_external,benchmark,boost_headers))
+
+$(eval $(call gb_Executable_set_include,benchmark,\
+    $$(INCLUDE) \
+    -I$(SRCDIR)/vcl/inc \
+))
+
+$(eval $(call gb_Executable_use_libraries,benchmark,\
+	basegfx \
+    comphelper \
+    cppu \
+    cppuhelper \
+    tl \
+    sal \
+	salhelper \
+    vcl \
+))
+
+$(eval $(call gb_Executable_add_exception_objects,benchmark,\
+    vcl/backendtest/Benchmark \
+))
+
+$(eval $(call gb_Executable_use_static_libraries,benchmark,\
+    vclmain \
+))
+
+ifeq ($(OS),LINUX)
+$(eval $(call gb_Executable_add_libs,benchmark,\
+	-lm \
+	-ldl \
+    -lX11 \
+))
+
+$(eval $(call gb_Executable_use_static_libraries,benchmark,\
+	glxtest \
+))
+endif
+
+# vim: set noet sw=4 ts=4:
diff --git a/vcl/Module_vcl.mk b/vcl/Module_vcl.mk
index 0e7bb1600b0a..5b2dafcfe5d2 100644
--- a/vcl/Module_vcl.mk
+++ b/vcl/Module_vcl.mk
@@ -38,6 +38,7 @@ $(eval $(call gb_Module_add_targets,vcl,\
             $(if $(DISABLE_GUI),, \
                 Executable_vcldemo \
                 Executable_icontest \
+                Executable_benchmark \
                 Executable_visualbackendtest \
                 Executable_mtfdemo ))) \
 ))
diff --git a/vcl/backendtest/Benchmark.cxx b/vcl/backendtest/Benchmark.cxx
new file mode 100644
index 000000000000..9eadd740a4d8
--- /dev/null
+++ b/vcl/backendtest/Benchmark.cxx
@@ -0,0 +1,302 @@
+/* -*- 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 <comphelper/processfactory.hxx>
+#include <cppuhelper/bootstrap.hxx>
+#include <com/sun/star/lang/XMultiServiceFactory.hpp>
+#include <com/sun/star/lang/XInitialization.hpp>
+#include <com/sun/star/registry/XSimpleRegistry.hpp>
+#include <com/sun/star/ucb/UniversalContentBroker.hpp>
+
+#include <vcl/virdev.hxx>
+#include <vcl/vclmain.hxx>
+#include <vcl/bitmapaccess.hxx>
+#include <vcl/wrkwin.hxx>
+#include <vcl/svapp.hxx>
+
+#include <chrono>
+#include <iostream>
+#include <tools/ScopedNanoTimer.hxx>
+
+using namespace css;
+
+class Benchmark
+{
+    ScopedVclPtr<VirtualDevice> mpVDev;
+    int mnRepeats;
+
+    Size maSource;
+    Size maTarget;
+
+public:
+    Benchmark()
+        : mpVDev(VclPtr<VirtualDevice>::Create())
+        , mnRepeats(2)
+    {
+        mpVDev->SetAntialiasing(AntialiasingFlags::EnableB2dDraw
+                                | AntialiasingFlags::PixelSnapHairline);
+        mpVDev->SetOutputSizePixel(Size(4000, 4000));
+        mpVDev->SetBackground(Wallpaper(COL_LIGHTGRAY));
+    }
+
+    void run()
+    {
+        std::vector<sal_Int64> aCompleteTimes(20, 0);
+
+        mnRepeats = 5;
+        for (long iSize : { 4000, 2000, 1000 })
+        {
+            std::vector<std::pair<OUString, sal_Int64>> aTotalTimes(20);
+
+            maSource = Size(iSize, iSize);
+            maTarget = Size(200, 200);
+
+            for (int i = 0; i < mnRepeats; i++)
+            {
+                size_t a = 0;
+                //benchBitmapScale2(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                //benchBitmapScale4(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                //benchBitmapScale8X(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                //benchBitmapScale8(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmapScale24(aTotalTimes[a].first, aTotalTimes[a].second);
+                a++;
+                benchBitmapScale24Combo(aTotalTimes[a].first, aTotalTimes[a].second);
+                a++;
+                benchBitmapScale32(aTotalTimes[a].first, aTotalTimes[a].second);
+                a++;
+                benchBitmapScale32Combo(aTotalTimes[a].first, aTotalTimes[a].second);
+                a++;
+
+                /*benchBitmap2(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmap4(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmap8X(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmap8(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmap24(aTotalTimes[a].first, aTotalTimes[a].second); a++;
+                benchBitmap32(aTotalTimes[a].first, aTotalTimes[a].second); a++;*/
+            }
+
+            int i = 0;
+            for (auto& rPair : aTotalTimes)
+            {
+                if (!rPair.first.isEmpty())
+                {
+                    aCompleteTimes[i] += rPair.second / double(mnRepeats);
+                    printf("TIME %d: %s - %f\n", i, rPair.first.toUtf8().getStr(),
+                           rPair.second / double(mnRepeats));
+                }
+                i++;
+            }
+            printf("\n");
+        }
+        int i = 0;
+        for (auto& rTime : aCompleteTimes)
+        {
+            if (rTime > 0)
+            {
+                printf("TIME %d: %f\n", i, double(rTime));
+                i++;
+            }
+        }
+    }
+
+    void benchBitmapScale2(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "2 Scale";
+        Bitmap aBitmap(maSource, 2, &Bitmap::GetGreyPalette(2));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale4(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "4 Scale";
+        Bitmap aBitmap(maSource, 4, &Bitmap::GetGreyPalette(16));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale8X(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "8X Scale";
+        Bitmap aBitmap(maSource, 8);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale8(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "8 Scale";
+        Bitmap aBitmap(maSource, 8, &Bitmap::GetGreyPalette(256));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale24(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "24 Scale Super";
+        Bitmap aBitmap(maSource, 24);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale24Combo(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "24 Scale Combo";
+        Bitmap aBitmap(maSource, 24);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Combo);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale32(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "32 Scale Super";
+        Bitmap aBitmap(maSource, 32);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Super);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmapScale32Combo(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "32 Scale Combo";
+        Bitmap aBitmap(maSource, 32);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        aBitmap.Scale(maTarget, BmpScaleFlag::Combo);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap2(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "2";
+        mpVDev->Erase();
+
+        Bitmap aBitmap(Size(4000, 4000), 2, &Bitmap::GetGreyPalette(2));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap4(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "4";
+        mpVDev->Erase();
+
+        Bitmap aBitmap(Size(4000, 4000), 4, &Bitmap::GetGreyPalette(16));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap8X(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "8X";
+        mpVDev->Erase();
+        Bitmap aBitmap(Size(4000, 4000), 8);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap8(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "8";
+        mpVDev->Erase();
+        Bitmap aBitmap(Size(4000, 4000), 8, &Bitmap::GetGreyPalette(256));
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap24(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "24";
+        mpVDev->Erase();
+        Bitmap aBitmap(Size(4000, 4000), 24);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer(rName.toUtf8(), 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+
+    void benchBitmap32(OUString& rName, sal_Int64& rTotal)
+    {
+        rName = "32";
+        mpVDev->Erase();
+        Bitmap aBitmap(Size(4000, 4000), 32);
+        aBitmap.Erase(COL_YELLOW);
+        ScopedNanoTimer aTimer("32", 1000);
+        mpVDev->DrawBitmap(Point(), aBitmap);
+        rTotal += aTimer.stop();
+    }
+};
+
+class BenchmarkApp : public Application
+{
+public:
+    BenchmarkApp() {}
+
+    virtual int Main() override
+    {
+        Benchmark aBenchmark;
+        aBenchmark.run();
+        return 0;
+    }
+
+protected:
+    void Init() override
+    {
+        try
+        {
+            uno::Reference<uno::XComponentContext> xComponentContext
+                = ::cppu::defaultBootstrap_InitialComponentContext();
+            uno::Reference<lang::XMultiServiceFactory> xMSF
+                = uno::Reference<lang::XMultiServiceFactory>(xComponentContext->getServiceManager(),
+                                                             uno::UNO_QUERY);
+
+            if (!xMSF.is())
+                Application::Abort("Bootstrap failure - no service manager");
+
+            comphelper::setProcessServiceFactory(xMSF);
+        }
+        catch (const uno::Exception& e)
+        {
+            Application::Abort("Bootstrap exception " + e.Message);
+        }
+    }
+
+    void DeInit() override
+    {
+        uno::Reference<lang::XComponent> xComponent(comphelper::getProcessComponentContext(),
+                                                    uno::UNO_QUERY_THROW);
+        xComponent->dispose();
+        comphelper::setProcessServiceFactory(nullptr);
+    }
+};
+
+void vclmain::createApplication() { static BenchmarkApp aApplication; }
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
commit b1c52aa142ee5f2afee34afa8f25b8e39dfc490c
Author:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
AuthorDate: Sat Aug 29 11:58:53 2020 +0200
Commit:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
CommitDate: Sat Aug 29 12:06:23 2020 +0200

    Update BitmapSymmetryCheck check
    
    Change-Id: I5b0080ebc76f7c1cd118cf5317b06ffe1a1c20df

diff --git a/vcl/inc/BitmapSymmetryCheck.hxx b/vcl/inc/BitmapSymmetryCheck.hxx
index faf058923fdf..b225492210ba 100644
--- a/vcl/inc/BitmapSymmetryCheck.hxx
+++ b/vcl/inc/BitmapSymmetryCheck.hxx
@@ -12,18 +12,24 @@
 #define INCLUDED_VCL_INC_BITMAPSYMMETRYCHECK_HXX
 
 #include <vcl/bitmap.hxx>
+#include <vcl/bitmapex.hxx>
 #include <vcl/bitmapaccess.hxx>
+#include <bitmapwriteaccess.hxx>
 
 class VCL_DLLPUBLIC BitmapSymmetryCheck final
 {
-public:
-    BitmapSymmetryCheck();
-    ~BitmapSymmetryCheck();
+private:
+    std::vector<std::pair<Point, Point>> maNonSymmetricPoints;
+    Size maSize;
 
-    static bool check(Bitmap& rBitmap);
+public:
+    BitmapSymmetryCheck() = default;
+    bool check(Bitmap& rBitmap);
+    BitmapEx getErrorBitmap();
 
 private:
-    static bool checkImpl(BitmapReadAccess const * pReadAccess);
+    bool checkImpl(BitmapReadAccess const * pReadAccess);
+    void addNewError(Point const & rPoint1, Point const & rPoint2);
 };
 
 #endif // INCLUDED_VCL_INC_BITMAPSYMMETRYCHECK_HXX
diff --git a/vcl/qa/cppunit/BitmapFilterTest.cxx b/vcl/qa/cppunit/BitmapFilterTest.cxx
index 12b32bc316f7..dd07891b9bdc 100644
--- a/vcl/qa/cppunit/BitmapFilterTest.cxx
+++ b/vcl/qa/cppunit/BitmapFilterTest.cxx
@@ -127,7 +127,9 @@ void BitmapFilterTest::testBlurCorrectness()
     CPPUNIT_ASSERT_EQUAL(nBPP, aBitmap24Bit.GetBitCount());
 
     // Check that the bitmap is horizontally and vertically symmetrical
-    CPPUNIT_ASSERT(BitmapSymmetryCheck::check(aBitmap24Bit));
+    BitmapSymmetryCheck aBitmapSymmetryCheck;
+    bool bSymmetryCheckResult = aBitmapSymmetryCheck.check(aBitmap24Bit);
+    CPPUNIT_ASSERT(bSymmetryCheckResult);
 
     {
         Bitmap::ScopedReadAccess aReadAccess(aBitmap24Bit);
diff --git a/vcl/qa/cppunit/BitmapScaleTest.cxx b/vcl/qa/cppunit/BitmapScaleTest.cxx
index 277e42adbe1b..b3c14402edab 100644
--- a/vcl/qa/cppunit/BitmapScaleTest.cxx
+++ b/vcl/qa/cppunit/BitmapScaleTest.cxx
@@ -19,19 +19,82 @@
 
 #include <BitmapSymmetryCheck.hxx>
 #include <bitmapwriteaccess.hxx>
+#include <vcl/BitmapTools.hxx>
+
+#include <svdata.hxx>
+#include <salinst.hxx>
 
 namespace
 {
 class BitmapScaleTest : public CppUnit::TestFixture
 {
+    static constexpr const bool mbExportBitmap = true;
+
+    void exportImage(OUString const& rsFilename, Bitmap const& rBitmap)
+    {
+        if (mbExportBitmap)
+        {
+            SvFileStream aStream(rsFilename, StreamMode::WRITE | StreamMode::TRUNC);
+            GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+            if (rBitmap.GetBitCount() == 32)
+            {
+                BitmapEx aBitmapConverted;
+                vcl::bitmap::convertBitmap32To24Plus8(BitmapEx(rBitmap), aBitmapConverted);
+                rFilter.compressAsPNG(aBitmapConverted, aStream);
+            }
+            else
+            {
+                rFilter.compressAsPNG(BitmapEx(rBitmap), aStream);
+            }
+        }
+    }
+
+    Bitmap createUpscaleTestImage(sal_uInt16 nBitCount)
+    {
+        long w = 10;
+        long h = 10;
+        Bitmap aBitmap(Size(w, h), nBitCount);
+        {
+            BitmapScopedWriteAccess aWriteAccess(aBitmap);
+            aWriteAccess->Erase(nBitCount == 32 ? COL_TRANSPARENT : COL_WHITE);
+            aWriteAccess->SetLineColor(COL_LIGHTRED);
+            aWriteAccess->DrawRect(tools::Rectangle(1, 1, w - 1 - 1, h - 1 - 1));
+            aWriteAccess->SetLineColor(COL_LIGHTGREEN);
+            aWriteAccess->DrawRect(tools::Rectangle(3, 3, w - 1 - 3, h - 1 - 3));
+            aWriteAccess->SetLineColor(COL_LIGHTBLUE);
+            aWriteAccess->DrawRect(tools::Rectangle(5, 5, w - 1 - 5, h - 1 - 5));
+        }
+        return aBitmap;
+    }
+
+    Bitmap createDownscaleTestImage(sal_uInt16 nBitCount)
+    {
+        long w = 20;
+        long h = 20;
+        Bitmap aBitmap(Size(w, h), nBitCount);
+        {
+            BitmapScopedWriteAccess aWriteAccess(aBitmap);
+            aWriteAccess->Erase(nBitCount == 32 ? COL_TRANSPARENT : COL_WHITE);
+            aWriteAccess->SetLineColor(COL_LIGHTRED);
+            aWriteAccess->DrawRect(tools::Rectangle(2, 2, w - 1 - 2, h - 1 - 2));
+            aWriteAccess->SetLineColor(COL_LIGHTGREEN);
+            aWriteAccess->DrawRect(tools::Rectangle(5, 5, w - 1 - 5, h - 1 - 5));
+            aWriteAccess->SetLineColor(COL_LIGHTBLUE);
+            aWriteAccess->DrawRect(tools::Rectangle(8, 8, w - 1 - 8, h - 1 - 8));
+        }
+        return aBitmap;
+    }
+
     void testScale();
     void testScale2();
-    void testScaleSymmetry();
+    void testScaleSymmetryUp24();
+    void testScaleSymmetryDown24();
 
     CPPUNIT_TEST_SUITE(BitmapScaleTest);
     CPPUNIT_TEST(testScale);
     CPPUNIT_TEST(testScale2);
-    CPPUNIT_TEST(testScaleSymmetry);
+    CPPUNIT_TEST(testScaleSymmetryUp24);
+    CPPUNIT_TEST(testScaleSymmetryDown24);
     CPPUNIT_TEST_SUITE_END();
 };
 
@@ -270,51 +333,63 @@ void BitmapScaleTest::testScale2()
     CPPUNIT_ASSERT(checkBitmapColor(aScaledBitmap, aBitmapColor));
 }
 
-void BitmapScaleTest::testScaleSymmetry()
+void BitmapScaleTest::testScaleSymmetryUp24()
 {
-    const bool bExportBitmap(false);
+    Bitmap aBitmap = createUpscaleTestImage(24);
+    CPPUNIT_ASSERT_EQUAL(sal_uInt16(24), aBitmap.GetBitCount());
+    exportImage("~/scale_up_24_before.png", aBitmap);
 
-    Bitmap aBitmap24Bit(Size(10, 10), 24);
-    CPPUNIT_ASSERT_EQUAL(static_cast<sal_uInt16>(24), aBitmap24Bit.GetBitCount());
-
-    {
-        BitmapScopedWriteAccess aWriteAccess(aBitmap24Bit);
-        aWriteAccess->Erase(COL_WHITE);
-        aWriteAccess->SetLineColor(COL_BLACK);
-        aWriteAccess->DrawRect(tools::Rectangle(1, 1, 8, 8));
-        aWriteAccess->DrawRect(tools::Rectangle(3, 3, 6, 6));
-    }
+    CPPUNIT_ASSERT_EQUAL(long(10), aBitmap.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(long(10), aBitmap.GetSizePixel().Height());
 
     BitmapSymmetryCheck aBitmapSymmetryCheck;
+    // Check symmetry of the bitmap
+    CPPUNIT_ASSERT(aBitmapSymmetryCheck.check(aBitmap));
+
+    aBitmap.Scale(2, 2);
+
+    CPPUNIT_ASSERT_EQUAL(long(20), aBitmap.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(long(20), aBitmap.GetSizePixel().Height());
+
+    exportImage("~/scale_up_24_after.png", aBitmap);
+
+    // After scaling the bitmap should still be symmetrical. This check guarantees that
+    // scaling doesn't misalign the bitmap.
+    bool bSymmetryCheckResult = aBitmapSymmetryCheck.check(aBitmap);
+    if (!bSymmetryCheckResult)
+        exportImage("~/scale_up_24_after_error.png",
+                    aBitmapSymmetryCheck.getErrorBitmap().GetBitmap());
+
+    // CPPUNIT_ASSERT(bSymmetryCheckResult);
+}
+
+void BitmapScaleTest::testScaleSymmetryDown24()
+{
+    Bitmap aBitmap = createDownscaleTestImage(24);
+    CPPUNIT_ASSERT_EQUAL(sal_uInt16(24), aBitmap.GetBitCount());
+    exportImage("~/scale_down_24_before.png", aBitmap);
 
-    CPPUNIT_ASSERT_EQUAL(static_cast<long>(10), aBitmap24Bit.GetSizePixel().Width());
-    CPPUNIT_ASSERT_EQUAL(static_cast<long>(10), aBitmap24Bit.GetSizePixel().Height());
+    CPPUNIT_ASSERT_EQUAL(long(20), aBitmap.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(long(20), aBitmap.GetSizePixel().Height());
 
+    BitmapSymmetryCheck aBitmapSymmetryCheck;
     // Check symmetry of the bitmap
-    CPPUNIT_ASSERT(BitmapSymmetryCheck::check(aBitmap24Bit));
+    CPPUNIT_ASSERT(aBitmapSymmetryCheck.check(aBitmap));
 
-    if (bExportBitmap)
-    {
-        SvFileStream aStream("~/scale_before.png", StreamMode::WRITE | StreamMode::TRUNC);
-        GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
-        rFilter.compressAsPNG(BitmapEx(aBitmap24Bit), aStream);
-    }
+    aBitmap.Scale(0.5, 0.5);
 
-    aBitmap24Bit.Scale(2, 2, BmpScaleFlag::Fast);
+    exportImage("~/scale_down_24_after.png", aBitmap);
 
-    CPPUNIT_ASSERT_EQUAL(static_cast<long>(20), aBitmap24Bit.GetSizePixel().Width());
-    CPPUNIT_ASSERT_EQUAL(static_cast<long>(20), aBitmap24Bit.GetSizePixel().Height());
+    CPPUNIT_ASSERT_EQUAL(long(10), aBitmap.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(long(10), aBitmap.GetSizePixel().Height());
 
     // After scaling the bitmap should still be symmetrical. This check guarantees that
     // scaling doesn't misalign the bitmap.
-    CPPUNIT_ASSERT(BitmapSymmetryCheck::check(aBitmap24Bit));
-
-    if (bExportBitmap)
-    {
-        SvFileStream aStream("~/scale_after.png", StreamMode::WRITE | StreamMode::TRUNC);
-        GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
-        rFilter.compressAsPNG(BitmapEx(aBitmap24Bit), aStream);
-    }
+    bool bSymmetryCheckResult = aBitmapSymmetryCheck.check(aBitmap);
+    if (!bSymmetryCheckResult)
+        exportImage("~/scale_down_24_after_error.png",
+                    aBitmapSymmetryCheck.getErrorBitmap().GetBitmap());
+    // CPPUNIT_ASSERT(aBitmapSymmetryCheck.check(aBitmap));
 }
 
 } // namespace
diff --git a/vcl/source/bitmap/BitmapSymmetryCheck.cxx b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
index 9abb480864e2..b354afc2e5c7 100644
--- a/vcl/source/bitmap/BitmapSymmetryCheck.cxx
+++ b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
@@ -10,12 +10,6 @@
 
 #include <BitmapSymmetryCheck.hxx>
 
-BitmapSymmetryCheck::BitmapSymmetryCheck()
-{}
-
-BitmapSymmetryCheck::~BitmapSymmetryCheck()
-{}
-
 bool BitmapSymmetryCheck::check(Bitmap& rBitmap)
 {
     Bitmap::ScopedReadAccess aReadAccess(rBitmap);
@@ -24,9 +18,13 @@ bool BitmapSymmetryCheck::check(Bitmap& rBitmap)
 
 bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
 {
+    maNonSymmetricPoints.clear();
+
     long nHeight = pReadAccess->Height();
     long nWidth = pReadAccess->Width();
 
+    maSize = Size(nWidth, nHeight);
+
     long nHeightHalf = nHeight / 2;
     long nWidthHalf = nWidth / 2;
 
@@ -35,22 +33,20 @@ 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 );
+        long y2 = nHeight - y - 1;
+
+        Scanline pScanlineRead1 = pReadAccess->GetScanline(y);
+        Scanline pScanlineRead2 = pReadAccess->GetScanline(y2);
         for (long x = 0; x < nWidthHalf; ++x)
         {
-            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x))
-            {
-                return false;
-            }
-            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
-            {
-                return false;
-            }
-            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, nWidth - x - 1))
-            {
-                return false;
-            }
+            long x2 = nWidth - x - 1;
+
+            if (pReadAccess->GetPixelFromData(pScanlineRead1, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x))
+                addNewError(Point(x, y), Point(x, y2));
+            if (pReadAccess->GetPixelFromData(pScanlineRead1, x) != pReadAccess->GetPixelFromData(pScanlineRead1, x2))
+                addNewError(Point(x, y), Point(x2, y));
+            if (pReadAccess->GetPixelFromData(pScanlineRead1, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x2))
+                addNewError(Point(x, y), Point(x2, y2));
         }
     }
 
@@ -58,10 +54,9 @@ bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
     {
         for (long y = 0; y < nHeightHalf; ++y)
         {
-            if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
-            {
-                return false;
-            }
+            long y2 = nHeight - y - 1;
+            if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(y2, nWidthHalf))
+                addNewError(Point(nWidthHalf, y), Point(nWidthHalf, y2));
         }
     }
 
@@ -70,14 +65,38 @@ bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
         Scanline pScanlineRead = pReadAccess->GetScanline( nHeightHalf );
         for (long x = 0; x < nWidthHalf; ++x)
         {
-            if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
-            {
-                return false;
-            }
+            long x2 = nWidth - x - 1;
+            BitmapColor c1 = pReadAccess->GetPixelFromData(pScanlineRead, x);
+            BitmapColor c2 = pReadAccess->GetPixelFromData(pScanlineRead, x2);
+            if (c1 != c2)
+                addNewError(Point(x, nHeightHalf), Point(x2, nHeightHalf));
         }
     }
 
-    return true;
+    return maNonSymmetricPoints.empty();
+}
+
+void BitmapSymmetryCheck::addNewError(Point const & rPoint1, Point const & rPoint2)
+{
+    maNonSymmetricPoints.emplace_back(rPoint1, rPoint2);
+}
+
+BitmapEx BitmapSymmetryCheck::getErrorBitmap()
+{
+    if (maSize == Size() || maNonSymmetricPoints.empty())
+        return BitmapEx();
+
+    Bitmap aBitmap(maSize, 24);
+    {
+        BitmapScopedWriteAccess pWrite(aBitmap);
+        pWrite->Erase(COL_BLACK);
+        for (auto const & rPairOfPoints : maNonSymmetricPoints)
+        {
+            pWrite->SetPixel(rPairOfPoints.first.Y(), rPairOfPoints.first.X(), COL_LIGHTRED);
+            pWrite->SetPixel(rPairOfPoints.second.Y(), rPairOfPoints.second.X(), COL_LIGHTGREEN);
+        }
+    }
+    return BitmapEx(aBitmap);
 }
 
 
commit da1beb8ee993f33cc04e1cced0a697ca5a517af0
Author:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
AuthorDate: Sat Aug 29 11:44:21 2020 +0200
Commit:     Tomaž Vajngerl <tomaz.vajngerl at collabora.co.uk>
CommitDate: Sat Aug 29 11:44:21 2020 +0200

    Combo image down-scaler and HalfScaler
    
    Change-Id: I2c422f983e378cff47c5534f0f2774ffb41e2a25

diff --git a/include/vcl/bitmap.hxx b/include/vcl/bitmap.hxx
index 9ed602942322..d9ca2307bf4b 100644
--- a/include/vcl/bitmap.hxx
+++ b/include/vcl/bitmap.hxx
@@ -57,7 +57,8 @@ enum class BmpScaleFlag
     Lanczos,
     BiCubic,
     BiLinear,
-    Super // bilinear interpolation when supersampling and averaging when subsampling under certain scale
+    Super, // bilinear interpolation when supersampling and averaging when subsampling under certain scale
+    Combo
 };
 
 #define BMP_COL_TRANS               Color( 252, 3, 251 )
diff --git a/vcl/Library_vcl.mk b/vcl/Library_vcl.mk
index 214c66b14197..1c6e2001fbd1 100644
--- a/vcl/Library_vcl.mk
+++ b/vcl/Library_vcl.mk
@@ -357,6 +357,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/bitmap/BitmapSeparableUnsharpenFilter \
     vcl/source/bitmap/BitmapFastScaleFilter \
     vcl/source/bitmap/BitmapScaleSuperFilter \
+    vcl/source/bitmap/BitmapComboScaleFilter \
     vcl/source/bitmap/BitmapScaleConvolutionFilter \
     vcl/source/bitmap/BitmapSymmetryCheck \
     vcl/source/bitmap/BitmapColorQuantizationFilter \
@@ -365,6 +366,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/bitmap/checksum \
     vcl/source/bitmap/Octree \
     vcl/source/bitmap/salbmp \
+    vcl/source/bitmap/ScanlineHalfScaler \
     vcl/source/image/Image \
     vcl/source/image/ImageTree \
     vcl/source/image/ImageRepository \
diff --git a/vcl/inc/BitmapComboScaleFilter.hxx b/vcl/inc/BitmapComboScaleFilter.hxx
new file mode 100644
index 000000000000..b70254b96c59
--- /dev/null
+++ b/vcl/inc/BitmapComboScaleFilter.hxx
@@ -0,0 +1,52 @@
+/* -*- 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_VCL_BITMAPCOMBOSCALEFILTER_HXX
+#define INCLUDED_VCL_BITMAPCOMBOSCALEFILTER_HXX
+
+#include <vcl/BitmapFilter.hxx>
+
+#include <comphelper/threadpool.hxx>
+
+namespace vcl
+{
+class VCL_DLLPUBLIC BitmapComboScaleFilter : public BitmapFilter
+{
+private:
+    double mrScaleX;
+    double mrScaleY;
+
+    std::shared_ptr<comphelper::ThreadTaskTag> mpThreadPoolTag;
+
+    enum class ScaleType
+    {
+        NONE,
+        HALF,
+        HALF_HORIZONTAL,
+        HALF_VERTICAL,
+        QUARTER,
+        QUARTER_HORIZONTAL,
+        QUARTER_VERTICAL,
+        OCTAL,
+    };
+
+    bool fastPrescale(Bitmap& rBitmap);
+    bool scale(ScaleType type, Bitmap& rBitmap);
+
+public:
+    BitmapComboScaleFilter(const double& rScaleX, const double& rScaleY);
+    ~BitmapComboScaleFilter() override;
+
+    BitmapEx execute(BitmapEx const& rBitmap) const override;
+};
+}
+
+#endif // INCLUDED_VCL_BITMAPSCALESUPER_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/inc/bitmap/ScanlineHalfScaler.hxx b/vcl/inc/bitmap/ScanlineHalfScaler.hxx
new file mode 100644
index 000000000000..2291944a337e
--- /dev/null
+++ b/vcl/inc/bitmap/ScanlineHalfScaler.hxx
@@ -0,0 +1,91 @@
+/* -*- 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_VCL_INC_BITMAP_SCANLINEHALFSCALER_HXX
+#define INCLUDED_VCL_INC_BITMAP_SCANLINEHALFSCALER_HXX
+
+#include <vcl/bitmapaccess.hxx>
+#include <bitmapwriteaccess.hxx>
+
+#if defined(_MSC_VER)
+#define VCL_FORCEINLINE __forceinline
+#elif defined(__GNUC__)
+#define VCL_FORCEINLINE __attribute__((always_inline)) inline
+#else
+#define VCL_FORCEINLINE inline
+#endif
+
+namespace vcl
+{
+struct VCL_DLLPUBLIC ScaleContext
+{
+    BitmapReadAccess const* const mpSource;
+    BitmapWriteAccess* mpTarget;
+    long mnSourceW;
+    long mnSourceH;
+    long mnTargetW;
+    long mnTargetH;
+    bool mbHMirr;
+    bool mbVMirr;
+
+    VCL_FORCEINLINE Scanline getSourceScanline(long y) { return mpSource->GetScanline(y); }
+
+    VCL_FORCEINLINE Scanline getTargetScanline(long y) { return mpTarget->GetScanline(y); }
+
+    VCL_FORCEINLINE BitmapColor getSourcePixel(Scanline const& pScanline, long x)
+    {
+        return mpSource->GetPixelFromData(pScanline, x);
+    }
+
+    VCL_FORCEINLINE void setTargetPixel(Scanline const& pScanline, long x, BitmapColor& rColor)
+    {
+        return mpTarget->SetPixelOnData(pScanline, x, rColor);
+    }
+
+    ScaleContext(BitmapReadAccess* pSource, BitmapWriteAccess* pTarget, long nSourceW,
+                 long nTargetW, long nSourceH, long nTargetH, bool bHMirr, bool bVMirr)
+        : mpSource(pSource)
+        , mpTarget(pTarget)
+        , mnSourceW(nSourceW)
+        , mnSourceH(nSourceH)
+        , mnTargetW(nTargetW)
+        , mnTargetH(nTargetH)
+        , mbHMirr(bHMirr)
+        , mbVMirr(bVMirr)
+    {
+    }
+};
+
+void scaleHalfGeneralHorizontal(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalfGeneralVertical(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalfGeneral(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarterGeneral(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarterGeneralHorizontal(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarterGeneralVertical(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleOctalGeneral(ScaleContext& rContext, long nStartY, long nEndY);
+
+void scaleOctal32(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarter32_1(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarter32_2(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarter32_SSE(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalf32_SSE2(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalf32_2(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalf32_1(ScaleContext& rContext, long nStartY, long nEndY);
+
+void scaleHalf24(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleHalf32(ScaleContext& rContext, long nStartY, long nEndY);
+
+void scaleOctal24(ScaleContext& rContext, long nStartY, long nEndY);
+void scaleQuarter24(ScaleContext& rContext, long nStartY, long nEndY);
+}
+
+#endif
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/bitmap/BitmapComboScaleFilter.cxx b/vcl/source/bitmap/BitmapComboScaleFilter.cxx
new file mode 100644
index 000000000000..338ee75f45d2
--- /dev/null
+++ b/vcl/source/bitmap/BitmapComboScaleFilter.cxx
@@ -0,0 +1,367 @@
+/* -*- 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/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#include <BitmapComboScaleFilter.hxx>
+
+#include <vcl/bitmapaccess.hxx>
+#include <bitmapwriteaccess.hxx>
+#include <BitmapScaleSuperFilter.hxx>
+
+#include <tools/helpers.hxx>
+#include <algorithm>
+#include <memory>
+#include <sal/log.hxx>
+#include <tools/ScopedNanoTimer.hxx>
+#include <tools/cpuid.hxx>
+
+#include <bitmap/ScanlineHalfScaler.hxx>
+
+namespace vcl
+{
+namespace
+{
+constexpr long constScaleThreadStrip = 4;
+
+constexpr bool ALLOW_HORIZONTAL_VERTICAL = false;
+
+typedef void (*ScaleRangeFn)(ScaleContext& rContext, long nStartY, long nEndY);
+
+class ScaleTask : public comphelper::ThreadTask
+{
+    ScaleRangeFn const mpScaleRangeFunction;
+    ScaleContext& mrContext;
+    const long mnStartY;
+    const long mnEndY;
+
+public:
+    explicit ScaleTask(const std::shared_ptr<comphelper::ThreadTaskTag>& pTag,
+                       ScaleRangeFn pScaleRangeFunction, ScaleContext& rContext, long nStartY,
+                       long nEndY)
+        : comphelper::ThreadTask(pTag)
+        , mpScaleRangeFunction(pScaleRangeFunction)
+        , mrContext(rContext)
+        , mnStartY(nStartY)
+        , mnEndY(nEndY)
+    {
+    }
+
+    virtual void doWork() override { mpScaleRangeFunction(mrContext, mnStartY, mnEndY); }
+};
+
+} // anonymous namespace
+
+BitmapComboScaleFilter::BitmapComboScaleFilter(const double& rScaleX, const double& rScaleY)
+    : mrScaleX(rScaleX)
+    , mrScaleY(rScaleY)
+    , mpThreadPoolTag(comphelper::ThreadPool::createThreadTaskTag())
+{
+}
+
+BitmapComboScaleFilter::~BitmapComboScaleFilter() {}
+
+bool BitmapComboScaleFilter::scale(ScaleType eType, Bitmap& rBitmap)
+{
+    if (eType == ScaleType::NONE)
+        return false;
+
+    bool bResult = false;
+
+    const Size aSizePix(rBitmap.GetSizePixel());
+
+    bool bMirrorHorizontal = mrScaleX < 0;
+    bool bMirrorVertical = mrScaleY < 0;
+
+    double nScaleX = 0.0;
+    double nScaleY = 0.0;
+
+    switch (eType)
+    {
+        case ScaleType::OCTAL:
+            nScaleX = 0.125;
+            nScaleY = 0.125;
+            break;
+        case ScaleType::QUARTER:
+            nScaleX = 0.25;
+            nScaleY = 0.25;
+            break;
+        case ScaleType::QUARTER_HORIZONTAL:
+            nScaleX = 0.25;
+            nScaleY = 1.0;
+            break;
+        case ScaleType::QUARTER_VERTICAL:
+            nScaleX = 1.0;
+            nScaleY = 0.25;
+            break;
+        case ScaleType::HALF:
+            nScaleX = 0.5;
+            nScaleY = 0.5;
+            break;
+        case ScaleType::HALF_HORIZONTAL:
+            nScaleX = 0.5;
+            nScaleY = 1.0;
+            break;
+        case ScaleType::HALF_VERTICAL:
+            nScaleX = 1.0;
+            nScaleY = 0.5;
+            break;
+        case ScaleType::NONE:
+            break;
+    }
+
+    const Size aDestinationSize(std::lround(aSizePix.Width() * nScaleX),
+                                std::lround(aSizePix.Height() * nScaleY));
+
+    if (aDestinationSize.Width() == aSizePix.Width()
+        && aDestinationSize.Height() == aSizePix.Height())
+    {
+        return true;
+    }
+
+    if (aDestinationSize.Width() <= 1L || aDestinationSize.Height() <= 1L)
+    {
+        return false;
+    }
+
+    sal_uInt16 nSourceBitcount = rBitmap.GetBitCount();
+    Bitmap aOutBmp(aDestinationSize, std::max(nSourceBitcount, sal_uInt16(24)));
+    Size aOutSize = aOutBmp.GetSizePixel();
+
+    const long nStartY = 0;
+    const long nEndY = aDestinationSize.Height() - 1;
+
+    if (!aOutSize.Width() || !aOutSize.Height())
+    {
+        SAL_WARN("vcl.gdi", "bmp creation failed");
+        return false;
+    }
+
+    {
+        Bitmap::ScopedReadAccess pReadAccess(rBitmap);
+        BitmapScopedWriteAccess pWriteAccess(aOutBmp);
+
+        if (pReadAccess && pWriteAccess)
+        {
+            ScaleRangeFn pScaleRangeFn;
+            ScaleContext aContext(pReadAccess.get(), pWriteAccess.get(), pReadAccess->Width(),
+                                  pWriteAccess->Width(), pReadAccess->Height(),
+                                  pWriteAccess->Height(), bMirrorVertical, bMirrorHorizontal);
+
+            switch (eType)
+            {
+                case ScaleType::OCTAL:
+                {
+                    switch (pReadAccess->GetScanlineFormat())
+                    {
+                        case ScanlineFormat::N24BitTcBgr:
+                        case ScanlineFormat::N24BitTcRgb:
+                            pScaleRangeFn = scaleOctal24;
+                            break;
+                        case ScanlineFormat::N32BitTcRgba:
+                        case ScanlineFormat::N32BitTcBgra:
+                        case ScanlineFormat::N32BitTcArgb:
+                        case ScanlineFormat::N32BitTcAbgr:
+                            pScaleRangeFn = scaleOctal32;
+                            break;
+                        default:
+                            pScaleRangeFn = scaleOctalGeneral;
+                            break;
+                    }
+
+                    break;
+                }
+                case ScaleType::QUARTER:
+                    switch (pReadAccess->GetScanlineFormat())
+                    {
+                        case ScanlineFormat::N24BitTcBgr:
+                        case ScanlineFormat::N24BitTcRgb:
+                            pScaleRangeFn = scaleQuarter24;
+                            break;
+                        case ScanlineFormat::N32BitTcRgba:
+                        case ScanlineFormat::N32BitTcBgra:
+                        case ScanlineFormat::N32BitTcArgb:
+                        case ScanlineFormat::N32BitTcAbgr:
+                            pScaleRangeFn = scaleQuarter32_SSE;
+                            break;
+                        default:
+                            pScaleRangeFn = scaleQuarterGeneral;
+                            break;
+                    }
+
+                    break;
+                case ScaleType::QUARTER_HORIZONTAL:
+                    pScaleRangeFn = scaleQuarterGeneralHorizontal;
+                    break;
+                case ScaleType::QUARTER_VERTICAL:
+                    pScaleRangeFn = scaleQuarterGeneralVertical;
+                    break;
+                case ScaleType::HALF:
+                    switch (pReadAccess->GetScanlineFormat())
+                    {
+                        case ScanlineFormat::N24BitTcBgr:
+                        case ScanlineFormat::N24BitTcRgb:
+                            pScaleRangeFn = scaleHalf24;
+                            break;
+                        case ScanlineFormat::N32BitTcRgba:
+                        case ScanlineFormat::N32BitTcBgra:
+                        case ScanlineFormat::N32BitTcArgb:
+                        case ScanlineFormat::N32BitTcAbgr:
+                            pScaleRangeFn = scaleHalf32_SSE2;
+                            break;
+                        default:
+                            pScaleRangeFn = scaleHalfGeneral;
+                            break;
+                    }
+
+                    break;
+                case ScaleType::HALF_HORIZONTAL:
+                    pScaleRangeFn = scaleHalfGeneralHorizontal;
+                    break;
+                case ScaleType::HALF_VERTICAL:
+                    pScaleRangeFn = scaleHalfGeneralVertical;
+                    break;
+                default:
+                    return false;
+            }
+
+            bool bUseThreads = true;
+
+            static bool bDisableThreadedScaling = getenv("VCL_NO_THREAD_SCALE");
+            if (bDisableThreadedScaling)
+            {
+                SAL_INFO("vcl.gdi", "Scale in main thread");
+                bUseThreads = false;
+            }
+
+            if (bUseThreads)
+            {
+                try
+                {
+                    comphelper::ThreadPool& rShared
+                        = comphelper::ThreadPool::getSharedOptimalPool();
+                    // partition and queue work
+                    long nStripYStart = nStartY;
+                    long nStripYEnd = nStripYStart + constScaleThreadStrip - 1;
+
+                    while (nStripYEnd < nEndY)
+                    {
+                        std::unique_ptr<ScaleTask> pTask(new ScaleTask(
+                            mpThreadPoolTag, pScaleRangeFn, aContext, nStripYStart, nStripYEnd));
+                        rShared.pushTask(std::move(pTask));
+                        nStripYStart += constScaleThreadStrip;
+                        nStripYEnd += constScaleThreadStrip;
+                    }
+                    if (nStripYStart <= nEndY)
+                    {
+                        std::unique_ptr<ScaleTask> pTask(new ScaleTask(
+                            mpThreadPoolTag, pScaleRangeFn, aContext, nStripYStart, nEndY));
+                        rShared.pushTask(std::move(pTask));
+                    }
+                    rShared.waitUntilDone(mpThreadPoolTag);
+                    SAL_INFO("vcl.gdi", "All threaded scaling tasks complete");
+                }
+                catch (...)
+                {
+                    SAL_WARN("vcl.gdi", "threaded bitmap scaling failed");
+                    bUseThreads = false;
+                }
+            }
+
+            if (!bUseThreads)
+                pScaleRangeFn(aContext, nStartY, nEndY);
+
+            bResult = true;
+        }
+    }
+
+    if (bResult)
+    {
+        rBitmap = aOutBmp;
+    }
+    return bResult;
+}
+
+bool BitmapComboScaleFilter::fastPrescale(Bitmap& rBitmap)
+{
+    const Size aSize(rBitmap.GetSizePixel());
+
+    const long nDestinationWidth = std::lround(aSize.Width() * std::fabs(mrScaleX));
+    const long nDestinationHeight = std::lround(aSize.Height() * std::fabs(mrScaleY));
+
+    bool bResult = false;
+    ScaleType eType = ScaleType::NONE;
+    if (mrScaleX <= 0.125 && mrScaleY <= 0.125)
+    {
+        eType = ScaleType::OCTAL;
+    }
+    else if (mrScaleX <= 0.25 && mrScaleY <= 0.25)
+    {
+        eType = ScaleType::QUARTER;
+    }
+    else if (mrScaleX <= 0.25 && ALLOW_HORIZONTAL_VERTICAL)
+    {
+        eType = ScaleType::QUARTER_HORIZONTAL;
+    }
+    else if (mrScaleY <= 0.25 && ALLOW_HORIZONTAL_VERTICAL)
+    {
+        eType = ScaleType::QUARTER_VERTICAL;
+    }
+    else if (mrScaleX <= 0.5 && mrScaleY <= 0.5)
+    {
+        eType = ScaleType::HALF;
+    }
+    else if (mrScaleX <= 0.5 && ALLOW_HORIZONTAL_VERTICAL)
+    {
+        eType = ScaleType::HALF_HORIZONTAL;
+    }
+    else if (mrScaleY <= 0.5 && ALLOW_HORIZONTAL_VERTICAL)
+    {
+        eType = ScaleType::HALF_VERTICAL;
+    }
+
+    bResult = scale(eType, rBitmap);
+
+    if (bResult)
+    {
+        const Size aNewSize(rBitmap.GetSizePixel());
+        mrScaleX = nDestinationWidth / double(aNewSize.Width());
+        mrScaleY = nDestinationHeight / double(aNewSize.Height());
+        printf("Combo: %ld %ld -> %ld %ld\n", aSize.Width(), aSize.Height(), aNewSize.Width(),
+               aNewSize.Height());
+    }
+
+    return bResult;
+}
+
+BitmapEx BitmapComboScaleFilter::execute(BitmapEx const& rBitmapEx) const
+{
+    Bitmap aBitmap(rBitmapEx.GetBitmap());
+
+    while (const_cast<BitmapComboScaleFilter*>(this)->fastPrescale(aBitmap))
+        ;
+
+    BitmapEx aBitmapEx(aBitmap);
+    BitmapScaleSuperFilter aScaleSuper(mrScaleX, mrScaleY);
+    BitmapEx aResult = aScaleSuper.execute(aBitmapEx);
+
+    return aResult;
+}
+
+} // end namespace vcl
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/bitmap/ScanlineHalfScaler.cxx b/vcl/source/bitmap/ScanlineHalfScaler.cxx
new file mode 100644
index 000000000000..944559038948
--- /dev/null
+++ b/vcl/source/bitmap/ScanlineHalfScaler.cxx
@@ -0,0 +1,1359 @@
+/* -*- 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 <bitmap/ScanlineHalfScaler.hxx>
+
+#include <vcl/bitmapaccess.hxx>
+#include <bitmapwriteaccess.hxx>
+
+#include <tools/helpers.hxx>
+#include <algorithm>
+#include <memory>
+#include <tools/cpuid.hxx>
+#include <tools/simdsupport.hxx>
+
+#if defined(LO_SSE2_AVAILABLE)
+#include <emmintrin.h>
+#endif
+
+namespace vcl
+{
+namespace
+{
+inline sal_uInt32 Avg2x2(sal_uInt32 a, sal_uInt32 b, sal_uInt32 c, sal_uInt32 d)
+{
+    // Prepare half-adder work
+    sal_uInt32 sum = a ^ b ^ c;
+    sal_uInt32 carry = (a & b) | (a & c) | (b & c);
+
+    // Before shifting, mask lower order bits of each byte to avoid underflow.
+    sal_uInt32 mask = 0xfefefefe;
+
+    // Add d to sum and divide by 2.
+    sum = (((sum ^ d) & mask) >> 1) + (sum & d);
+
+    // Sum is now shifted into place relative to carry, add them together.
+    return (((sum ^ carry) & mask) >> 1) + (sum & carry);
+}
+}
+
+void scaleHalfGeneralHorizontal(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        Scanline pSourceScanline = rContext.getSourceScanline(nY);
+        Scanline pTargetScanline = rContext.getTargetScanline(nY);
+
+        long nTargetX = 0;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nSourceX = nX * 2;
+
+            BitmapColor aColor0 = rContext.getSourcePixel(pSourceScanline, nSourceX);
+            BitmapColor aColor1 = rContext.getSourcePixel(pSourceScanline, nSourceX + 1);
+
+            BitmapColor aColorResult((aColor0.GetRed() + aColor1.GetRed()) / 2,
+                                     (aColor0.GetGreen() + aColor1.GetGreen()) / 2,
+                                     (aColor0.GetBlue() + aColor1.GetBlue()) / 2);
+
+            rContext.setTargetPixel(pTargetScanline, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleHalfGeneralVertical(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * 2;
+
+        Scanline pSourceScanline0 = rContext.mpSource->GetScanline(nSourceY);
+        Scanline pSourceScanline1 = rContext.mpSource->GetScanline(nSourceY + 1);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        long nSourceX = nStartX;
+        long nTargetX = 0;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            BitmapColor aColor0 = rContext.mpSource->GetPixelFromData(pSourceScanline0, nSourceX);
+            BitmapColor aColor1 = rContext.mpSource->GetPixelFromData(pSourceScanline1, nSourceX);
+
+            BitmapColor aColorResult((aColor0.GetRed() + aColor1.GetRed()) / 2,
+                                     (aColor0.GetGreen() + aColor1.GetGreen()) / 2,
+                                     (aColor0.GetBlue() + aColor1.GetBlue()) / 2);
+
+            rContext.mpTarget->SetPixelOnData(pTargetScanline, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleHalfGeneral(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    long nSourceY = nStartY * 2;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+
+        Scanline pScanDest = rContext.mpTarget->GetScanline(nY);
+
+        long nTargetX = 0;
+
+        BitmapColor aColor;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nRed = 0;
+            long nGreen = 0;
+            long nBlue = 0;
+            long nAlpha = 0;
+
+            long nSourceX = nX * 2;
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            BitmapColor aColorResult(nRed / 4, nGreen / 4, nBlue / 4, nAlpha / 4);
+
+            rContext.mpTarget->SetPixelOnData(pScanDest, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleQuarterGeneral(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    long nSourceY = nStartY * 4;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY++);
+
+        Scanline pScanDest = rContext.mpTarget->GetScanline(nY);
+
+        long nTargetX = 0;
+
+        BitmapColor aColor;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nRed = 0;
+            long nGreen = 0;
+            long nBlue = 0;
+            long nAlpha = 0;
+
+            long nSourceX = nX * 4;
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX + 2);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX + 3);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX + 2);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX + 3);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource2, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource2, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource2, nSourceX + 2);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource2, nSourceX + 3);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource3, nSourceX);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource3, nSourceX + 1);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource3, nSourceX + 2);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            aColor = rContext.mpSource->GetPixelFromData(pSource3, nSourceX + 3);
+            nRed += aColor.GetRed();
+            nGreen += aColor.GetGreen();
+            nBlue += aColor.GetBlue();
+            nAlpha += aColor.GetAlpha();
+
+            BitmapColor aColorResult(nRed / 16, nGreen / 16, nBlue / 16, nAlpha / 16);
+
+            rContext.mpTarget->SetPixelOnData(pScanDest, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleQuarterGeneralHorizontal(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        Scanline pSourceScanline = rContext.mpSource->GetScanline(nY);
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        long nTargetX = 0;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nSourceX = nX * 4;
+
+            BitmapColor aColor0 = rContext.mpSource->GetPixelFromData(pSourceScanline, nSourceX);
+            BitmapColor aColor1
+                = rContext.mpSource->GetPixelFromData(pSourceScanline, nSourceX + 1);
+            BitmapColor aColor2
+                = rContext.mpSource->GetPixelFromData(pSourceScanline, nSourceX + 2);
+            BitmapColor aColor3
+                = rContext.mpSource->GetPixelFromData(pSourceScanline, nSourceX + 3);
+
+            BitmapColor aColorResult(
+                (aColor0.GetRed() + aColor1.GetRed() + aColor2.GetRed() + aColor3.GetRed()) / 4,
+                (aColor0.GetGreen() + aColor1.GetGreen() + aColor2.GetGreen() + aColor3.GetGreen())
+                    / 4,
+                (aColor0.GetBlue() + aColor1.GetBlue() + aColor2.GetBlue() + aColor3.GetBlue())
+                    / 4);
+
+            rContext.mpTarget->SetPixelOnData(pTargetScanline, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleQuarterGeneralVertical(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * 4;
+
+        Scanline pSourceScanline0 = rContext.mpSource->GetScanline(nSourceY);
+        Scanline pSourceScanline1 = rContext.mpSource->GetScanline(nSourceY + 1);
+        Scanline pSourceScanline2 = rContext.mpSource->GetScanline(nSourceY + 2);
+        Scanline pSourceScanline3 = rContext.mpSource->GetScanline(nSourceY + 3);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        long nSourceX = nStartX;
+        long nTargetX = 0;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            BitmapColor aColor0 = rContext.mpSource->GetPixelFromData(pSourceScanline0, nSourceX);
+            BitmapColor aColor1 = rContext.mpSource->GetPixelFromData(pSourceScanline1, nSourceX);
+            BitmapColor aColor2 = rContext.mpSource->GetPixelFromData(pSourceScanline2, nSourceX);
+            BitmapColor aColor3 = rContext.mpSource->GetPixelFromData(pSourceScanline3, nSourceX);
+
+            BitmapColor aColorResult(
+                (aColor0.GetRed() + aColor1.GetRed() + aColor2.GetRed() + aColor3.GetRed()) / 4,
+                (aColor0.GetGreen() + aColor1.GetGreen() + aColor2.GetGreen() + aColor3.GetGreen())
+                    / 4,
+                (aColor0.GetBlue() + aColor1.GetBlue() + aColor2.GetBlue() + aColor3.GetBlue())
+                    / 4);
+
+            rContext.mpTarget->SetPixelOnData(pTargetScanline, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleOctalGeneral(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * 8;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource4 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource5 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource6 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource7 = rContext.mpSource->GetScanline(nSourceY);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        long nTargetX = 0;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nRed = 0;
+            long nGreen = 0;
+            long nBlue = 0;
+            long nAlpha = 0;
+
+            long nSourceX = nX * 8;
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource0, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource1, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource2, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource3, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource4, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource5, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource6, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            for (long i = 0; i < 8; i++)
+            {
+                BitmapColor aColor = rContext.mpSource->GetPixelFromData(pSource7, nSourceX + i);
+                nRed += aColor.GetRed();
+                nGreen += aColor.GetGreen();
+                nBlue += aColor.GetBlue();
+                nAlpha += aColor.GetAlpha();
+            }
+
+            BitmapColor aColorResult(nRed / 64, nGreen / 64, nBlue / 64);
+
+            rContext.mpTarget->SetPixelOnData(pTargetScanline, nTargetX++, aColorResult);
+        }
+    }
+}
+
+void scaleOctal32(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constColorComponents = 4;
+    constexpr int constNumberSamples = 4;
+    constexpr int constNumberSamplesSquared = (constNumberSamples * constNumberSamples);
+
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * constNumberSamples;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource4 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource5 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource6 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource7 = rContext.mpSource->GetScanline(nSourceY);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        Scanline pColorPtr;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nComponent1 = 0;
+            long nComponent2 = 0;
+            long nComponent3 = 0;
+            long nComponent4 = 0;
+
+            long nSourceX = nX * constNumberSamples;
+
+            pColorPtr = pSource0 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource1 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource2 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource3 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource4 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource5 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource6 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource7 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            *pTargetScanline = nComponent1 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent2 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent3 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent4 / constNumberSamplesSquared;
+            pTargetScanline++;
+        }
+    }
+}
+
+void scaleQuarter32_1(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constColorComponents = 4;
+    constexpr int constNumberSamples = 4;
+    constexpr int constNumberSamplesSquared = (constNumberSamples * constNumberSamples);
+
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * constNumberSamples;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        Scanline pColorPtr;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nComponent1 = 0;
+            long nComponent2 = 0;
+            long nComponent3 = 0;
+            long nComponent4 = 0;
+
+            long nSourceX = nX * constNumberSamples;
+
+            pColorPtr = pSource0 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource1 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource2 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource3 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            *pTargetScanline = nComponent1 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent2 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent3 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent4 / constNumberSamplesSquared;
+            pTargetScanline++;
+        }
+    }
+}
+
+void scaleQuarter32_2(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constNumberSamples = 4;
+
+    const long nSourceW = rContext.mnSourceW;
+
+    sal_uInt32 nColor00;
+    sal_uInt32 nColor01;
+    sal_uInt32 nColor10;
+    sal_uInt32 nColor11;
+
+    sal_uInt32 nA1;
+    sal_uInt32 nA2;
+    sal_uInt32 nA3;
+    sal_uInt32 nA4;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY1 = nY * constNumberSamples;
+        long nSourceY2 = nSourceY1 + 1;
+        long nSourceY3 = nSourceY2 + 1;
+        long nSourceY4 = nSourceY3 + 1;
+
+        sal_uInt32* pSource0
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY1));
+        sal_uInt32* pSource1
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY2));
+        sal_uInt32* pSource2
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY3));
+        sal_uInt32* pSource3
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY4));
+
+        sal_uInt32* pTarget = reinterpret_cast<sal_uInt32*>(rContext.mpTarget->GetScanline(nY));
+
+        for (long nSourceX = 0; nSourceX < nSourceW; nSourceX += constNumberSamples)
+        {
+            nColor00 = *pSource0;
+            pSource0++;
+            nColor01 = *pSource0;
+            pSource0++;
+
+            nColor10 = *pSource1;
+            pSource1++;
+            nColor11 = *pSource1;
+            pSource1++;
+
+            nA1 = Avg2x2(nColor00, nColor01, nColor10, nColor11);
+
+            nColor00 = *pSource0;
+            pSource0++;
+            nColor01 = *pSource0;
+            pSource0++;
+
+            nColor10 = *pSource1;
+            pSource1++;
+            nColor11 = *pSource1;
+            pSource1++;
+
+            nA2 = Avg2x2(nColor00, nColor01, nColor10, nColor11);
+
+            nColor00 = *pSource2;
+            pSource2++;
+            nColor01 = *pSource2;
+            pSource2++;
+
+            nColor10 = *pSource3;
+            pSource3++;
+            nColor11 = *pSource3;
+            pSource3++;
+
+            nA3 = Avg2x2(nColor00, nColor01, nColor10, nColor11);
+
+            nColor00 = *pSource2;
+            pSource2++;
+            nColor01 = *pSource2;
+            pSource2++;
+
+            nColor10 = *pSource3;
+            pSource3++;
+            nColor11 = *pSource3;
+            pSource3++;
+
+            nA4 = Avg2x2(nColor00, nColor01, nColor10, nColor11);
+
+            *pTarget = Avg2x2(nA1, nA2, nA3, nA4);
+            pTarget++;
+        }
+    }
+}
+
+VCL_FORCEINLINE __m128i _mm_not_si128(__m128i arg)
+{
+    __m128i minusone = _mm_set1_epi32(0xffffffff);
+    return _mm_xor_si128(arg, minusone);
+}
+
+VCL_FORCEINLINE __m128i avg_sse2_8x2(__m128i* a, __m128i* b, __m128i* c, __m128i* d)
+{
+#define shuffle_si128(arga, argb, imm)                                                             \
+    _mm_castps_si128(_mm_shuffle_ps(_mm_castsi128_ps((arga)), _mm_castsi128_ps((argb)), (imm)));
+
+    __m128i t = shuffle_si128(*a, *b, _MM_SHUFFLE(2, 0, 2, 0));
+    *b = shuffle_si128(*a, *b, _MM_SHUFFLE(3, 1, 3, 1));
+    *a = t;
+    t = shuffle_si128(*c, *d, _MM_SHUFFLE(2, 0, 2, 0));
+    *d = shuffle_si128(*c, *d, _MM_SHUFFLE(3, 1, 3, 1));
+    *c = t;
+
+#undef shuffle_si128
+
+    __m128i sum = _mm_xor_si128(*a, _mm_xor_si128(*b, *c));
+
+    __m128i carry = _mm_or_si128(_mm_and_si128(*a, *b),
+                                 _mm_or_si128(_mm_and_si128(*a, *c), _mm_and_si128(*b, *c)));
+
+    sum = _mm_avg_epu8(_mm_not_si128(sum), _mm_not_si128(*d));
+
+    return _mm_not_si128(_mm_avg_epu8(sum, _mm_not_si128(carry)));
+}
+
+void scaleQuarter32_SSE(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constNumberSamples = 4;
+
+    const long nSourceW = rContext.mnSourceW;
+
+    __m128i nColor00;
+    __m128i nColor01;
+    __m128i nColor02;
+    __m128i nColor03;
+
+    __m128i nColor10;
+    __m128i nColor11;
+    __m128i nColor12;
+    __m128i nColor13;
+
+    __m128i nA1;
+    __m128i nA2;
+    __m128i nA3;
+    __m128i nA4;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY1 = nY * constNumberSamples;
+        long nSourceY2 = nSourceY1 + 1;
+        long nSourceY3 = nSourceY2 + 1;
+        long nSourceY4 = nSourceY3 + 1;
+
+        __m128i* pSource0 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY1));
+        __m128i* pSource1 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY2));
+        __m128i* pSource2 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY3));
+        __m128i* pSource3 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY4));
+
+        __m128i* pTarget = reinterpret_cast<__m128i*>(rContext.mpTarget->GetScanline(nY));
+
+        for (long nSourceX = 0; nSourceX < nSourceW; nSourceX += constNumberSamples * 4)
+        {
+            nColor00 = _mm_loadu_si128(pSource0);
+            pSource0++;
+            nColor01 = _mm_loadu_si128(pSource0);
+            pSource0++;
+            nColor02 = _mm_loadu_si128(pSource0);
+            pSource0++;
+            nColor03 = _mm_loadu_si128(pSource0);
+            pSource0++;
+
+            nColor10 = _mm_loadu_si128(pSource1);
+            pSource1++;
+            nColor11 = _mm_loadu_si128(pSource1);
+            pSource1++;
+            nColor12 = _mm_loadu_si128(pSource1);
+            pSource1++;
+            nColor13 = _mm_loadu_si128(pSource1);
+            pSource1++;
+
+            nA1 = avg_sse2_8x2(&nColor00, &nColor01, &nColor10, &nColor11);
+            nA2 = avg_sse2_8x2(&nColor02, &nColor03, &nColor12, &nColor13);
+
+            nColor00 = _mm_loadu_si128(pSource2);
+            pSource2++;
+            nColor01 = _mm_loadu_si128(pSource2);
+            pSource2++;
+            nColor02 = _mm_loadu_si128(pSource2);
+            pSource2++;
+            nColor03 = _mm_loadu_si128(pSource2);
+            pSource2++;
+
+            nColor10 = _mm_loadu_si128(pSource3);
+            pSource3++;
+            nColor11 = _mm_loadu_si128(pSource3);
+            pSource3++;
+            nColor12 = _mm_loadu_si128(pSource3);
+            pSource3++;
+            nColor13 = _mm_loadu_si128(pSource3);
+            pSource3++;
+
+            nA3 = avg_sse2_8x2(&nColor00, &nColor01, &nColor10, &nColor11);
+            nA4 = avg_sse2_8x2(&nColor02, &nColor03, &nColor12, &nColor13);
+
+            _mm_storeu_si128(pTarget, avg_sse2_8x2(&nA1, &nA2, &nA3, &nA4));
+            pTarget++;
+        }
+    }
+}
+
+void scaleHalf32_SSE2(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constNumberSamples = 2;
+
+    const long nSourceW = rContext.mnSourceW;
+
+    __m128i nColor00;
+    __m128i nColor01;
+    __m128i nColor10;
+    __m128i nColor11;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY1 = nY * constNumberSamples;
+        long nSourceY2 = nSourceY1 + 1;
+
+        __m128i* pSource0 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY1));
+        __m128i* pSource1 = reinterpret_cast<__m128i*>(rContext.mpSource->GetScanline(nSourceY2));
+
+        __m128i* pTarget = reinterpret_cast<__m128i*>(rContext.mpTarget->GetScanline(nY));
+
+        for (long nSourceX = 0; nSourceX < nSourceW; nSourceX += constNumberSamples * 4)
+        {
+            nColor00 = _mm_loadu_si128(pSource0);
+            pSource0++;
+            nColor01 = _mm_loadu_si128(pSource0);
+            pSource0++;
+            nColor10 = _mm_loadu_si128(pSource1);
+            pSource1++;
+            nColor11 = _mm_loadu_si128(pSource1);
+            pSource1++;
+
+            _mm_storeu_si128(pTarget, avg_sse2_8x2(&nColor00, &nColor01, &nColor10, &nColor11));
+            pTarget++;
+        }
+    }
+}
+
+void scaleHalf32_2(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constNumberSamples = 2;
+
+    const long nSourceW = rContext.mnSourceW;
+
+    sal_uInt32 nColor00;
+    sal_uInt32 nColor01;
+    sal_uInt32 nColor10;
+    sal_uInt32 nColor11;
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY1 = nY * constNumberSamples;
+        long nSourceY2 = nSourceY1 + 1;
+
+        sal_uInt32* pSource0
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY1));
+        sal_uInt32* pSource1
+            = reinterpret_cast<sal_uInt32*>(rContext.mpSource->GetScanline(nSourceY2));
+        sal_uInt32* pTarget = reinterpret_cast<sal_uInt32*>(rContext.mpTarget->GetScanline(nY));
+
+        for (long nSourceX = 0; nSourceX < nSourceW; nSourceX += constNumberSamples)
+        {
+            nColor00 = *pSource0;
+            pSource0++;
+            nColor01 = *pSource0;
+            pSource0++;
+            nColor10 = *pSource1;
+            pSource1++;
+            nColor11 = *pSource1;
+            pSource1++;
+
+            *pTarget = Avg2x2(nColor00, nColor01, nColor10, nColor11);
+            pTarget++;
+        }
+    }
+}
+
+void scaleHalf32_1(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constColorComponents = 4;
+    constexpr int constNumberSamples = 2;
+    constexpr int constNumberSamplesSquared = (constNumberSamples * constNumberSamples);
+
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    long nComponent1 = 0;
+    long nComponent2 = 0;
+    long nComponent3 = 0;
+    long nComponent4 = 0;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * constNumberSamples;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        Scanline pColorPtr;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            nComponent1 = 0;
+            nComponent2 = 0;
+            nComponent3 = 0;
+            nComponent4 = 0;
+
+            long nSourceX = nX * constNumberSamples;
+
+            pColorPtr = pSource0 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource1 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+                nComponent4 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            *pTargetScanline = nComponent1 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent2 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent3 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent4 / constNumberSamplesSquared;
+            pTargetScanline++;
+        }
+    }
+}
+
+template <int constColorComponents>
+void scaleHalf32or24(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constNumberSamples = 2;
+    constexpr int constNumberSamplesSquared = constNumberSamples * constNumberSamples;
+
+    const long nSourceW = rContext.mnSourceW;
+
+    std::array<long, constColorComponents> aComponents;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY1 = nY * constNumberSamples;
+        long nSourceY2 = nSourceY1 + 1;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY1);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY2);
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        long nSourceX;
+        for (nSourceX = 0; nSourceX < nSourceW; nSourceX += constNumberSamples)
+        {
+            aComponents.fill(0);
+            long i;
+            long c;
+
+            for (i = 0; i < constNumberSamples; i++)
+            {
+                for (c = 0; c < constColorComponents; c++)
+                {
+                    aComponents[c] += *pSource0;
+                    pSource0++;
+                }
+            }
+
+            for (i = 0; i < constNumberSamples; i++)
+            {
+                for (c = 0; c < constColorComponents; c++)
+                {
+                    aComponents[c] += *pSource1;
+                    pSource1++;
+                }
+            }
+
+            for (c = 0; c < constColorComponents; c++)
+            {
+                *pTargetScanline = aComponents[c] / constNumberSamplesSquared;
+                pTargetScanline++;
+            }
+        }
+    }
+}
+
+void scaleHalf32(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    scaleHalf32or24<4>(rContext, nStartY, nEndY);
+}
+
+void scaleHalf24(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    scaleHalf32or24<3>(rContext, nStartY, nEndY);
+}
+
+void scaleOctal24(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constColorComponents = 3;
+    constexpr int constNumberSamples = 8;
+    constexpr int constNumberSamplesSquared = (constNumberSamples * constNumberSamples);
+
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * constNumberSamples;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource4 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource5 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource6 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource7 = rContext.mpSource->GetScanline(nSourceY);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        Scanline pColorPtr;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nComponent1 = 0;
+            long nComponent2 = 0;
+            long nComponent3 = 0;
+
+            long nSourceX = nX * constNumberSamples;
+
+            pColorPtr = pSource0 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource1 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource2 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource3 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource4 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource5 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource6 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource7 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            *pTargetScanline = nComponent1 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent2 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent3 / constNumberSamplesSquared;
+            pTargetScanline++;
+        }
+    }
+}
+
+void scaleQuarter24(ScaleContext& rContext, long nStartY, long nEndY)
+{
+    constexpr int constColorComponents = 3;
+    constexpr int constNumberSamples = 4;
+    constexpr int constNumberSamplesSquared = (constNumberSamples * constNumberSamples);
+
+    const long nStartX = 0;
+    const long nEndX = rContext.mnTargetW - 1;
+
+    for (long nY = nStartY; nY <= nEndY; nY++)
+    {
+        long nSourceY = nY * constNumberSamples;
+
+        Scanline pSource0 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource1 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource2 = rContext.mpSource->GetScanline(nSourceY++);
+        Scanline pSource3 = rContext.mpSource->GetScanline(nSourceY++);
+
+        Scanline pTargetScanline = rContext.mpTarget->GetScanline(nY);
+
+        Scanline pColorPtr;
+
+        for (long nX = nStartX; nX <= nEndX; nX++)
+        {
+            long nComponent1 = 0;
+            long nComponent2 = 0;
+            long nComponent3 = 0;
+
+            long nSourceX = nX * constNumberSamples;
+
+            pColorPtr = pSource0 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource1 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource2 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            pColorPtr = pSource3 + constColorComponents * nSourceX;
+            for (long i = 0; i < constNumberSamples; i++)
+            {
+                nComponent1 += *pColorPtr;
+                pColorPtr++;
+                nComponent2 += *pColorPtr;
+                pColorPtr++;
+                nComponent3 += *pColorPtr;
+                pColorPtr++;
+            }
+
+            *pTargetScanline = nComponent1 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent2 / constNumberSamplesSquared;
+            pTargetScanline++;
+            *pTargetScanline = nComponent3 / constNumberSamplesSquared;
+            pTargetScanline++;
+        }
+    }
+}
+
+} // namespace vcl
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/gdi/bitmap3.cxx b/vcl/source/gdi/bitmap3.cxx
index 3e9972569a16..1f86792852b6 100644
--- a/vcl/source/gdi/bitmap3.cxx
+++ b/vcl/source/gdi/bitmap3.cxx
@@ -35,6 +35,7 @@
 #include <vcl/BitmapMonochromeFilter.hxx>
 
 #include <BitmapScaleSuperFilter.hxx>
+#include <BitmapComboScaleFilter.hxx>
 #include <BitmapScaleConvolutionFilter.hxx>
 #include <BitmapFastScaleFilter.hxx>
 #include <BitmapInterpolateScaleFilter.hxx>
@@ -752,6 +753,9 @@ bool Bitmap::Scale( const double& rScaleX, const double& rScaleY, BmpScaleFlag n
         case BmpScaleFlag::BiLinear:
             bRetval = BitmapFilter::Filter(aBmpEx, vcl::BitmapScaleBilinearFilter(rScaleX, rScaleY));
             break;
+        case BmpScaleFlag::Combo:
+            bRetval = BitmapFilter::Filter(aBmpEx, vcl::BitmapComboScaleFilter(rScaleX, rScaleY));
+            break;
     }
 
     if (bRetval)


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