vcl/source/bitmap/BitmapSymmetryCheck.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  */
  10
  11 #include <BitmapSymmetryCheck.hxx>
  12
  13 BitmapSymmetryCheck::BitmapSymmetryCheck()
  14 {}
  15
  16 BitmapSymmetryCheck::~BitmapSymmetryCheck()
  17 {}
  18
  19 bool BitmapSymmetryCheck::check(Bitmap& rBitmap)
  20 {
  21     Bitmap::ScopedReadAccess aReadAccess(rBitmap);
  22     return checkImpl(aReadAccess.get());
  23 }
  24
  25 bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess* pReadAccess)
  26 {
  27     long nHeight = pReadAccess->Height();
  28     long nWidth = pReadAccess->Width();
  29
  30     long nHeightHalf = nHeight / 2;
  31     long nWidthHalf = nWidth / 2;
  32
  33     bool nHeightEven = (nHeight % 2) == 0;
  34     bool nWidthEven = (nWidth % 2) == 0;
  35
  36     for (long y = 0; y < nHeightHalf; ++y)
  37     {
  38         for (long x = 0; x < nWidthHalf; ++x)
  39         {
  40             if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, x))
  41             {
  42                 return false;
  43             }
  44             if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(y, nWidth - x - 1))
  45             {
  46                 return false;
  47             }
  48             if (pReadAccess->GetPixel(y, x) != pReadAccess->GetPixel(nHeight - y - 1, nWidth - x - 1))
  49             {
  50                 return false;
  51             }
  52         }
  53     }
  54
  55     if (nWidthEven)
  56     {
  57         for (long y = 0; y < nHeightHalf; ++y)
  58         {
  59             if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
  60             {
  61                 return false;
  62             }
  63         }
  64     }
  65
  66     if (nHeightEven)
  67     {
  68         for (long x = 0; x < nWidthHalf; ++x)
  69         {
  70             if (pReadAccess->GetPixel(nHeightHalf, x) != pReadAccess->GetPixel(nHeightHalf, nWidth - x - 1))
  71             {
  72                 return false;
  73             }
  74         }
  75     }
  76
  77     return true;
  78 }
  79
  80
  81 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */