tdf#159660: Add support for darken mode in feBlend

Change-Id: I56862163b7bf1177120081c95ab7851a5fc4019b
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/166428
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>

1 files changed, 57 insertions, 0 deletions

diff --git a/vcl/qa/cppunit/BitmapFilterTest.cxx b/vcl/qa/cppunit/BitmapFilterTest.cxx
index fb01bfde0018..dcb7bd587a5e 100644
--- a/vcl/qa/cppunit/BitmapFilterTest.cxx
+++ b/vcl/qa/cppunit/BitmapFilterTest.cxx
@@ -16,6 +16,7 @@
 #include <vcl/graphicfilter.hxx>
 
 #include <vcl/BitmapArithmeticBlendFilter.hxx>
+#include <vcl/BitmapDarkenBlendFilter.hxx>
 #include <vcl/BitmapMultiplyBlendFilter.hxx>
 #include <vcl/BitmapScreenBlendFilter.hxx>
 #include <vcl/BitmapBasicMorphologyFilter.hxx>
@@ -43,6 +44,7 @@ public:
     void testPerformance();
     void testGenerateStripRanges();
     void testMultiplyBlendFilter();
+    void testDarkenBlendFilter();
     void testScreenBlendFilter();
     void testArithmeticBlendFilter();
 
@@ -52,6 +54,7 @@ public:
     CPPUNIT_TEST(testPerformance);
     CPPUNIT_TEST(testGenerateStripRanges);
     CPPUNIT_TEST(testMultiplyBlendFilter);
+    CPPUNIT_TEST(testDarkenBlendFilter);
     CPPUNIT_TEST(testScreenBlendFilter);
     CPPUNIT_TEST(testArithmeticBlendFilter);
     CPPUNIT_TEST_SUITE_END();
@@ -339,6 +342,60 @@ void BitmapFilterTest::testMultiplyBlendFilter()
     }
 }
 
+void BitmapFilterTest::testDarkenBlendFilter()
+{
+    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
+    {
+        BitmapDarkenBlendFilter* pArithmeticFilter
+            = new BitmapDarkenBlendFilter(aRedBitmapEx, aRedBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(COL_LIGHTRED, aResBitmapEx.GetPixelColor(2, 2));
+    }
+
+    // different color
+    {
+        BitmapDarkenBlendFilter* pArithmeticFilter
+            = new BitmapDarkenBlendFilter(aRedBitmapEx, aGreenBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(Color(ColorAlpha, 0xFF, 0x00, 0x00, 0x00),
+                             aResBitmapEx.GetPixelColor(2, 2));
+    }
+
+    // transparent
+    {
+        BitmapDarkenBlendFilter* pArithmeticFilter
+            = new BitmapDarkenBlendFilter(aRedBitmapEx, aTransparentBitmapEx);
+        BitmapEx aResBitmapEx = pArithmeticFilter->execute();
+        CPPUNIT_ASSERT_EQUAL(Color(ColorAlpha, 0xFF, 0xFF, 0x00, 0x00),
+                             aResBitmapEx.GetPixelColor(2, 2));
+    }
+}
+
 void BitmapFilterTest::testScreenBlendFilter()
 {
     Bitmap aRedBitmap(Size(4, 4), vcl::PixelFormat::N24_BPP);