tdf#159660: Add support for lighten mode in feBlend

Change-Id: I17471a9c70a38d05de5ad476f817285fb2438e5a
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166429
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>

include/vcl/BitmapLightenBlendFilter.hxx

@@ -0,0 +1,29 @@
+/* -*- 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_BITMAPLIGHTENBLENDFILTER_HXX
+#define INCLUDED_VCL_BITMAPLIGHTENBLENDFILTER_HXX
+
+#include <vcl/bitmapex.hxx>
+
+class VCL_DLLPUBLIC BitmapLightenBlendFilter
+{
+private:
+    BitmapEx maBitmapEx;
+    BitmapEx maBitmapEx2;
+
+public:
+    BitmapLightenBlendFilter(BitmapEx const& rBmpEx, BitmapEx const& rBmpEx2);
+
+    virtual ~BitmapLightenBlendFilter();
+    BitmapEx execute();
+};
+#endif
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

svgio/inc/svgfeblendnode.hxx

@@ -27,6 +27,7 @@ namespace svgio::svgreader
 enum class Mode
 {
     Darken,
+    Lighten,
     Multiply,
     Normal,
     Screen

svgio/qa/cppunit/SvgImportTest.cxx

@@ -1909,6 +1909,50 @@ CPPUNIT_TEST_FIXTURE(Test, testDarkenBlend)
     CPPUNIT_ASSERT_EQUAL(OUString("008000"), aPixels[125]);
 }
 
+CPPUNIT_TEST_FIXTURE(Test, testLightenBlend)
+{
+    xmlDocUniquePtr pDocument = dumpAndParseSvg(u"/svgio/qa/cppunit/data/lightenBlend.svg");
+
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "height"_ostr, "150");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "width"_ostr, "150");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap/data"_ostr, 150);
+
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy11"_ostr, "150");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy12"_ostr, "0");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy13"_ostr, "20");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy21"_ostr, "0");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy22"_ostr, "150");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy23"_ostr, "20");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy31"_ostr, "0");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy32"_ostr, "0");
+    assertXPath(pDocument,
+            "/primitive2D/transform/transform/bitmap"_ostr, "xy33"_ostr, "1");
+
+    // Check the colors in the diagonal
+    OUString sDataRow = getXPath(pDocument, "/primitive2D/transform/transform/bitmap/data[25]"_ostr, "row"_ostr);
+    std::vector<OUString> aPixels = comphelper::string::split(sDataRow, ',');
+    CPPUNIT_ASSERT_EQUAL(OUString("ff0000"), aPixels[25]);
+
+    sDataRow = getXPath(pDocument, "/primitive2D/transform/transform/bitmap/data[75]"_ostr, "row"_ostr);
+    aPixels = comphelper::string::split(sDataRow, ',');
+    CPPUNIT_ASSERT_EQUAL(OUString("ff8000"), aPixels[75]);
+
+    sDataRow = getXPath(pDocument, "/primitive2D/transform/transform/bitmap/data[125]"_ostr, "row"_ostr);
+    aPixels = comphelper::string::split(sDataRow, ',');
+    CPPUNIT_ASSERT_EQUAL(OUString("008000"), aPixels[125]);
+}
+
 CPPUNIT_TEST_FIXTURE(Test, testTdf149880)
 {
     xmlDocUniquePtr pDocument = dumpAndParseSvg(u"/svgio/qa/cppunit/data/tdf149880.svg");

svgio/qa/cppunit/data/lightenBlend.svg

@@ -0,0 +1,8 @@
+<svg width="100" height="140" viewBox="0 0 200 280" xmlns="http://www.w3.org/2000/svg">
+  <filter id="filter" filterUnits="userSpaceOnUse" x="0" y="0" width="100%" height="100%">
+    <feFlood x="20" y="20" width="100" height="100" flood-color="red" flood-opacity="1" result="img1"></feFlood>
+    <feFlood x="50" y="50" width="100" height="100" flood-color="green" flood-opacity="1" result="img2"></feFlood>
+    <feBlend in="img1" in2="img2" mode="lighten"></feBlend>
+  </filter>
+  <use style="filter: url(#filter)"></use>
+</svg>

svgio/source/svgreader/svgfeblendnode.cxx

@@ -25,6 +25,7 @@
 #include <drawinglayer/converters.hxx>
 #include <basegfx/matrix/b2dhommatrixtools.hxx>
 #include <vcl/BitmapDarkenBlendFilter.hxx>
+#include <vcl/BitmapLightenBlendFilter.hxx>
 #include <vcl/BitmapMultiplyBlendFilter.hxx>
 #include <vcl/BitmapScreenBlendFilter.hxx>
 #include <vcl/BitmapTools.hxx>
@@ -84,6 +85,10 @@ void SvgFeBlendNode::parseAttribute(SVGToken aSVGToken, const OUString& aContent
                 {
                     maMode = Mode::Darken;
                 }
+                else if (o3tl::equalsIgnoreAsciiCase(o3tl::trim(aContent), u"lighten"))
+                {
+                    maMode = Mode::Lighten;
+                }
             }
             break;
         }
@@ -182,6 +187,11 @@ void SvgFeBlendNode::apply(drawinglayer::primitive2d::Primitive2DContainer& rTar
             BitmapDarkenBlendFilter aDarkenBlendFilter(aBmpEx, aBmpEx2);
             aResBmpEx = aDarkenBlendFilter.execute();
         }
+        else if (maMode == Mode::Lighten)
+        {
+            BitmapLightenBlendFilter aLightenBlendFilter(aBmpEx, aBmpEx2);
+            aResBmpEx = aLightenBlendFilter.execute();
+        }
 
         const drawinglayer::primitive2d::Primitive2DReference xRef(
             new drawinglayer::primitive2d::BitmapPrimitive2D(

vcl/Library_vcl.mk

@@ -346,6 +346,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/bitmap/BitmapAlphaClampFilter \
     vcl/source/bitmap/BitmapBasicMorphologyFilter \
     vcl/source/bitmap/BitmapDarkenBlendFilter \
+    vcl/source/bitmap/BitmapLightenBlendFilter \
     vcl/source/bitmap/BitmapMaskToAlphaFilter \
     vcl/source/bitmap/BitmapMonochromeFilter \
     vcl/source/bitmap/BitmapMultiplyBlendFilter \

vcl/qa/cppunit/BitmapFilterTest.cxx

@@ -17,6 +17,7 @@
 
 #include <vcl/BitmapArithmeticBlendFilter.hxx>
 #include <vcl/BitmapDarkenBlendFilter.hxx>
+#include <vcl/BitmapLightenBlendFilter.hxx>
 #include <vcl/BitmapMultiplyBlendFilter.hxx>
 #include <vcl/BitmapScreenBlendFilter.hxx>
 #include <vcl/BitmapBasicMorphologyFilter.hxx>
@@ -45,6 +46,7 @@ public:
     void testGenerateStripRanges();
     void testMultiplyBlendFilter();
     void testDarkenBlendFilter();
+    void testLightenBlendFilter();
     void testScreenBlendFilter();
     void testArithmeticBlendFilter();
 
@@ -55,6 +57,7 @@ public:
     CPPUNIT_TEST(testGenerateStripRanges);
     CPPUNIT_TEST(testMultiplyBlendFilter);
     CPPUNIT_TEST(testDarkenBlendFilter);
+    CPPUNIT_TEST(testLightenBlendFilter);
     CPPUNIT_TEST(testScreenBlendFilter);
     CPPUNIT_TEST(testArithmeticBlendFilter);
     CPPUNIT_TEST_SUITE_END();
@@ -396,6 +399,60 @@ void BitmapFilterTest::testDarkenBlendFilter()
     }
 }
 
+void BitmapFilterTest::testLightenBlendFilter()
+{
+    Bitmap aRedBitmap(Size(4, 4), vcl::PixelFormat::N24_BPP);
+    CPPUNIT_ASSERT_EQUAL(vcl::PixelFormat::N24_BPP, aRedBitmap.getPixelFormat());
+    {
+        BitmapScopedWriteAccess aWriteAccess(aRedBitmap);
+        aWriteAccess->Erase(COL_LIGHTRED);
+    }
+
+    Bitmap aGreenBitmap(Size(4, 4), vcl::PixelFormat::N24_BPP);
+    CPPUNIT_ASSERT_EQUAL(vcl::PixelFormat::N24_BPP, aGreenBitmap.getPixelFormat());
+    {
+        BitmapScopedWriteAccess aWriteAccess(aGreenBitmap);
+        aWriteAccess->Erase(COL_GREEN);
+    }
+
+    Bitmap aTransparentBitmap(Size(4, 4), vcl::PixelFormat::N24_BPP);
+    CPPUNIT_ASSERT_EQUAL(vcl::PixelFormat::N24_BPP, aTransparentBitmap.getPixelFormat());
+    {
+        BitmapScopedWriteAccess aWriteAccess(aTransparentBitmap);
+        aWriteAccess->Erase(COL_AUTO);
+    }
+
+    BitmapEx aRedBitmapEx(aRedBitmap);
+    BitmapEx aGreenBitmapEx(aGreenBitmap);
+    BitmapEx aTransparentBitmapEx(aTransparentBitmap);
+
+    // same color
+    {
+        BitmapLightenBlendFilter* pArithmeticFilter
+            = new BitmapLightenBlendFilter(aRedBitmapEx, aRedBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(COL_LIGHTRED, aResBitmapEx.GetPixelColor(2, 2));
+    }
+
+    // different color
+    {
+        BitmapLightenBlendFilter* pArithmeticFilter
+            = new BitmapLightenBlendFilter(aRedBitmapEx, aGreenBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(Color(ColorAlpha, 0xFF, 0xFF, 0x80, 0x00),
+                             aResBitmapEx.GetPixelColor(2, 2));
+    }
+
+    // transparent
+    {
+        BitmapLightenBlendFilter* pArithmeticFilter
+            = new BitmapLightenBlendFilter(aRedBitmapEx, aTransparentBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(Color(ColorAlpha, 0xFF, 0xFF, 0xFF, 0xFF),
+                             aResBitmapEx.GetPixelColor(2, 2));
+    }
+}
+
 void BitmapFilterTest::testScreenBlendFilter()
 {
     Bitmap aRedBitmap(Size(4, 4), vcl::PixelFormat::N24_BPP);

vcl/source/bitmap/BitmapLightenBlendFilter.cxx

@@ -0,0 +1,109 @@
+/* -*- 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/diagnose_ex.hxx>
+#include <vcl/BitmapLightenBlendFilter.hxx>
+#include <vcl/BitmapWriteAccess.hxx>
+#include <vcl/BitmapTools.hxx>
+
+BitmapLightenBlendFilter::BitmapLightenBlendFilter(BitmapEx const& rBitmapEx,
+                                                   BitmapEx const& rBitmapEx2)
+    : maBitmapEx(rBitmapEx)
+    , maBitmapEx2(rBitmapEx2)
+{
+}
+
+BitmapLightenBlendFilter::~BitmapLightenBlendFilter() {}
+
+static sal_uInt8 lcl_calculate(const sal_uInt8 aColor, const sal_uInt8 aAlpha,
+                               const sal_uInt8 aColor2, const sal_uInt8 aAlpha2)
+{
+    const double c1 = aColor / 255.0;
+    const double c2 = aColor2 / 255.0;
+    const double a1 = aAlpha / 255.0;
+    const double a2 = aAlpha2 / 255.0;
+    const double result = std::max((1.0 - a1) * c2 + c1, (1.0 - a2) * c1 + c2);
+    return result * 255.0;
+}
+
+static BitmapColor premultiply(const BitmapColor c)
+{
+    return BitmapColor(ColorAlpha, vcl::bitmap::premultiply(c.GetRed(), c.GetAlpha()),
+                       vcl::bitmap::premultiply(c.GetGreen(), c.GetAlpha()),
+                       vcl::bitmap::premultiply(c.GetBlue(), c.GetAlpha()), c.GetAlpha());
+}
+
+static BitmapColor unpremultiply(const BitmapColor c)
+{
+    return BitmapColor(ColorAlpha, vcl::bitmap::unpremultiply(c.GetRed(), c.GetAlpha()),
+                       vcl::bitmap::unpremultiply(c.GetGreen(), c.GetAlpha()),
+                       vcl::bitmap::unpremultiply(c.GetBlue(), c.GetAlpha()), c.GetAlpha());
+}
+
+BitmapEx BitmapLightenBlendFilter::execute()
+{
+    if (maBitmapEx.IsEmpty() || maBitmapEx2.IsEmpty())
+        return BitmapEx();
+
+    Size aSize = maBitmapEx.GetBitmap().GetSizePixel();
+    Size aSize2 = maBitmapEx2.GetBitmap().GetSizePixel();
+    sal_Int32 nHeight = std::min(aSize.getHeight(), aSize2.getHeight());
+    sal_Int32 nWidth = std::min(aSize.getWidth(), aSize2.getWidth());
+
+    BitmapScopedReadAccess pReadAccess(maBitmapEx.GetBitmap());
+    Bitmap aDstBitmap(Size(nWidth, nHeight), maBitmapEx.GetBitmap().getPixelFormat(),
+                      &pReadAccess->GetPalette());
+    Bitmap aDstAlpha(AlphaMask(Size(nWidth, nHeight)).GetBitmap());
+
+    {
+        // just to be on the safe side: let the
+        // ScopedAccessors get destructed before
+        // copy-constructing the resulting bitmap. This will
+        // rule out the possibility that cached accessor data
+        // is not yet written back.
+
+        BitmapScopedWriteAccess pWriteAccess(aDstBitmap);
+        BitmapScopedWriteAccess pAlphaWriteAccess(aDstAlpha);
+
+        if (pWriteAccess.get() != nullptr && pAlphaWriteAccess.get() != nullptr)
+        {
+            for (tools::Long y(0); y < nHeight; ++y)
+            {
+                Scanline pScanline = pWriteAccess->GetScanline(y);
+                Scanline pScanAlpha = pAlphaWriteAccess->GetScanline(y);
+                for (tools::Long x(0); x < nWidth; ++x)
+                {
+                    BitmapColor i1 = premultiply(maBitmapEx.GetPixelColor(x, y));
+                    BitmapColor i2 = premultiply(maBitmapEx2.GetPixelColor(x, y));
+                    sal_uInt8 r(
+                        lcl_calculate(i1.GetRed(), i1.GetAlpha(), i2.GetRed(), i2.GetAlpha()));
+                    sal_uInt8 g(
+                        lcl_calculate(i1.GetGreen(), i1.GetAlpha(), i2.GetGreen(), i2.GetAlpha()));
+                    sal_uInt8 b(
+                        lcl_calculate(i1.GetBlue(), i1.GetAlpha(), i2.GetBlue(), i2.GetAlpha()));
+                    sal_uInt8 a(
+                        lcl_calculate(i1.GetAlpha(), i1.GetAlpha(), i2.GetAlpha(), i2.GetAlpha()));
+
+                    pWriteAccess->SetPixelOnData(
+                        pScanline, x, unpremultiply(BitmapColor(ColorAlpha, r, g, b, a)));
+                    pAlphaWriteAccess->SetPixelOnData(pScanAlpha, x, BitmapColor(a));
+                }
+            }
+        }
+        else
+        {
+            // TODO(E2): Error handling!
+            ENSURE_OR_THROW(false, "BitmapLightenBlendFilter: could not access bitmap");
+        }
+    }
+
+    return BitmapEx(aDstBitmap, AlphaMask(aDstAlpha));
+}
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */