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 const * 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 bHeightEven = (nHeight % 2) == 0;
  34     bool bWidthEven = (nWidth % 2) == 0;
  35
  36     for (long y = 0; y < nHeightHalf; ++y)
  37     {
  38         Scanline pScanlineRead = pReadAccess->GetScanline( y );
  39         Scanline pScanlineRead2 = pReadAccess->GetScanline( nHeight - y - 1 );
  40         for (long x = 0; x < nWidthHalf; ++x)
  41         {
  42             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x))
  43             {
  44                 return false;
  45             }
  46             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
  47             {
  48                 return false;
  49             }
  50             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, nWidth - x - 1))
  51             {
  52                 return false;
  53             }
  54         }
  55     }
  56
  57     if (bWidthEven)
  58     {
  59         for (long y = 0; y < nHeightHalf; ++y)
  60         {
  61             if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
  62             {
  63                 return false;
  64             }
  65         }
  66     }
  67
  68     if (bHeightEven)
  69     {
  70         Scanline pScanlineRead = pReadAccess->GetScanline( nHeightHalf );
  71         for (long x = 0; x < nWidthHalf; ++x)
  72         {
  73             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
  74             {
  75                 return false;
  76             }
  77         }
  78     }
  79
  80     return true;
  81 }
  82
  83
  84 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */