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

Change-Id: I53d6e70018477abb9f98140a52697c1de0f90934

1 files changed, 88 insertions, 0 deletions

diff --git a/vcl/qa/cppunit/BitmapTest.cxx b/vcl/qa/cppunit/BitmapTest.cxx
new file mode 100644
index 000000000000..cc8534f22a6a
--- /dev/null
+++ b/vcl/qa/cppunit/BitmapTest.cxx
@@ -0,0 +1,88 @@
+/* -*- 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: */