vcl: tests for Bitmap, check for symmetry when scaling bitmaps

Change-Id: I53d6e70018477abb9f98140a52697c1de0f90934

vcl/CppunitTest_vcl_bitmap_test.mk

+# -*- 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 $(call gb_CppunitTest_CppunitTest,vcl_bitmap_test))
+
+$(eval $(call gb_CppunitTest_add_exception_objects,vcl_bitmap_test, \
+    vcl/qa/cppunit/BitmapTest \
+))
+
+$(eval $(call gb_CppunitTest_use_externals,vcl_bitmap_test,\
+	boost_headers \
+))
+
+$(eval $(call gb_CppunitTest_set_include,vcl_bitmap_test,\
+    $$(INCLUDE) \
+    -I$(SRCDIR)/vcl/inc \
+))
+
+$(eval $(call gb_CppunitTest_use_libraries,vcl_bitmap_test, \
+	comphelper \
+	cppu \
+	cppuhelper \
+	sal \
+    svt \
+	test \
+	tl \
+	unotest \
+	vcl \
+	utl \
+	$(gb_UWINAPI) \
+))
+
+$(eval $(call gb_CppunitTest_use_api,vcl_bitmap_test,\
+    udkapi \
+    offapi \
+))
+
+$(eval $(call gb_CppunitTest_use_ure,vcl_bitmap_test))
+$(eval $(call gb_CppunitTest_use_vcl,vcl_bitmap_test))
+
+$(eval $(call gb_CppunitTest_use_components,vcl_bitmap_test,\
+    configmgr/source/configmgr \
+    i18npool/util/i18npool \
+    ucb/source/core/ucb1 \
+    unotools/util/utl \
+))
+
+$(eval $(call gb_CppunitTest_use_configuration,vcl_bitmap_test))
+
+# vim: set noet sw=4 ts=4:

vcl/Library_vcl.mk

@@ -315,6 +315,7 @@ $(eval $(call gb_Library_add_exception_objects,vcl,\
     vcl/source/gdi/wall \
     vcl/source/bitmap/bitmapfilter \
     vcl/source/bitmap/bitmapscalesuper \
+    vcl/source/bitmap/BitmapSymmetryCheck \
     vcl/source/helper/canvasbitmap \
     vcl/source/helper/canvastools \
     vcl/source/helper/evntpost \

vcl/Module_vcl.mk

@@ -99,6 +99,7 @@ $(eval $(call gb_Module_add_targets,vcl,\
 endif
 
 $(eval $(call gb_Module_add_check_targets,vcl,\
+	CppunitTest_vcl_bitmap_test \
 	CppunitTest_vcl_fontcharmap \
 	CppunitTest_vcl_complextext \
 	CppunitTest_vcl_filters_test \

vcl/inc/BitmapSymmetryCheck.hxx

+/* -*- 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_BITMAPSYMMETRYCHECK_HXX
+#define INCLUDED_VCL_INC_BITMAPSYMMETRYCHECK_HXX
+
+#include <vcl/bitmap.hxx>
+#include <vcl/bmpacc.hxx>
+
+class VCL_DLLPUBLIC BitmapSymmetryCheck
+{
+public:
+    BitmapSymmetryCheck();
+    virtual ~BitmapSymmetryCheck();
+
+    bool check(Bitmap& rBitmap);
+
+protected:
+    virtual bool checkImpl(BitmapReadAccess* pReadAccess);
+};
+
+#endif // INCLUDED_VCL_INC_BITMAPSYMMETRYCHECK_HXX
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/qa/cppunit/BitmapTest.cxx

+/* -*- 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 <cppunit/TestAssert.h>
+#include <cppunit/TestFixture.h>
+#include <cppunit/extensions/HelperMacros.h>
+#include <cppunit/plugin/TestPlugIn.h>
+
+#include <vcl/bitmap.hxx>
+#include <vcl/bmpacc.hxx>
+
+#include <tools/stream.hxx>
+#include <vcl/graphicfilter.hxx>
+
+#include "BitmapSymmetryCheck.hxx"
+
+namespace
+{
+
+class BitmapTest : public CppUnit::TestFixture
+{
+    void testScale();
+
+    CPPUNIT_TEST_SUITE(BitmapTest);
+    CPPUNIT_TEST(testScale);
+    CPPUNIT_TEST_SUITE_END();
+};
+
+void BitmapTest::testScale()
+{
+    bool bExportBitmap(false);
+
+    Bitmap aBitmap24Bit(Size(10, 10), 24);
+    CPPUNIT_ASSERT_EQUAL(static_cast<sal_uInt16>(24), aBitmap24Bit.GetBitCount());
+
+    {
+        Bitmap::ScopedWriteAccess aWriteAccess(aBitmap24Bit);
+        aWriteAccess->Erase(COL_WHITE);
+        aWriteAccess->SetLineColor(COL_BLACK);
+        aWriteAccess->DrawRect(Rectangle(1, 1, 8, 8));
+        aWriteAccess->DrawRect(Rectangle(3, 3, 6, 6));
+    }
+
+    BitmapSymmetryCheck aBitmapSymmetryCheck;
+
+    CPPUNIT_ASSERT_EQUAL(static_cast<long>(10), aBitmap24Bit.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(static_cast<long>(10), aBitmap24Bit.GetSizePixel().Height());
+
+    // Check symmetry of the bitmap
+    CPPUNIT_ASSERT(aBitmapSymmetryCheck.check(aBitmap24Bit));
+
+    if (bExportBitmap)
+    {
+        SvFileStream aStream(OUString("~/scale_before.png"), StreamMode::WRITE | StreamMode::TRUNC);
+        GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+        rFilter.compressAsPNG(aBitmap24Bit, aStream, 9);
+    }
+
+    aBitmap24Bit.Scale(2, 2, BMP_SCALE_FAST);
+
+    CPPUNIT_ASSERT_EQUAL(static_cast<long>(20), aBitmap24Bit.GetSizePixel().Width());
+    CPPUNIT_ASSERT_EQUAL(static_cast<long>(20), aBitmap24Bit.GetSizePixel().Height());
+
+    // After scaling the bitmap should still be symmetrical. This check guarantees that
+    // scaling doesn't misalign the bitmap.
+    CPPUNIT_ASSERT(aBitmapSymmetryCheck.check(aBitmap24Bit));
+
+    if (bExportBitmap)
+    {
+        SvFileStream aStream(OUString("~/scale_after.png"), StreamMode::WRITE | StreamMode::TRUNC);
+        GraphicFilter& rFilter = GraphicFilter::GetGraphicFilter();
+        rFilter.compressAsPNG(aBitmap24Bit, aStream, 9);
+    }
+}
+
+} // namespace
+
+CPPUNIT_TEST_SUITE_REGISTRATION(BitmapTest);
+
+CPPUNIT_PLUGIN_IMPLEMENT();
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */

vcl/source/bitmap/BitmapSymmetryCheck.cxx

+/* -*- 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 <BitmapSymmetryCheck.hxx>
+
+BitmapSymmetryCheck::BitmapSymmetryCheck()
+{}
+
+BitmapSymmetryCheck::~BitmapSymmetryCheck()
+{}
+
+bool BitmapSymmetryCheck::check(Bitmap& rBitmap)
+{
+    Bitmap::ScopedReadAccess aReadAccess(rBitmap);
+    return checkImpl(aReadAccess.get());
+}
+
+bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess* pReadAccess)
+{
+    long nHeight = pReadAccess->Height();
+    long nWidth = pReadAccess->Width();
+
+    long nHeightHalf = nHeight / 2;
+    long nWidthHalf = nWidth / 2;
+
+    bool nHeightEven = (nHeight % 2) == 0;
+    bool nWidthEven = (nWidth % 2) == 0;
+
+    for (long y = 0; y < nHeightHalf; ++y)
+    {
+        for (long x = 0; x < nWidthHalf; ++x)
+        {
+            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, x))
+            {
+                return false;
+            }
+            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(y, nWidth - x - 1))
+            {
+                return false;
+            }
+            if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, nWidth - x - 1))
+            {
+                return false;
+            }
+        }
+    }
+
+    if (nWidthEven)
+    {
+        for (long y = 0; y < nHeightHalf; ++y)
+        {
+            if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
+            {
+                return false;
+            }
+        }
+    }
+
+    if (nHeightEven)
+    {
+        for (long x = 0; x < nWidthHalf; ++x)
+        {
+            if (pReadAccess->GetPixel(nHeightHalf, x) != pReadAccess->GetPixel(nHeightHalf, nWidth - x - 1))
+            {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */