1 files changed, 84 insertions, 0 deletions
diff --git a/vcl/source/bitmap/BitmapSymmetryCheck.cxx b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
new file mode 100644
index 000000000..9abb48086
--- /dev/null
+++ b/vcl/source/bitmap/BitmapSymmetryCheck.cxx
@@ -0,0 +1,84 @@
+/* -*- 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 const * pReadAccess)
+{
+    long nHeight = pReadAccess->Height();
+    long nWidth = pReadAccess->Width();
+
+    long nHeightHalf = nHeight / 2;
+    long nWidthHalf = nWidth / 2;
+
+    bool bHeightEven = (nHeight % 2) == 0;
+    bool bWidthEven = (nWidth % 2) == 0;
+
+    for (long y = 0; y < nHeightHalf; ++y)
+    {
+        Scanline pScanlineRead = pReadAccess->GetScanline( y );
+        Scanline pScanlineRead2 = pReadAccess->GetScanline( nHeight - y - 1 );
+        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;
+            }
+        }
+    }
+
+    if (bWidthEven)
+    {
+        for (long y = 0; y < nHeightHalf; ++y)
+        {
+            if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
+            {
+                return false;
+            }
+        }
+    }
+
+    if (bHeightEven)
+    {
+        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;
+            }
+        }
+    }
+
+    return true;
+}
+
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */