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 <vcl/BitmapReadAccess.hxx>
  12
  13 #include <BitmapSymmetryCheck.hxx>
  14
  15 BitmapSymmetryCheck::BitmapSymmetryCheck()
  16 {}
  17
  18 BitmapSymmetryCheck::~BitmapSymmetryCheck()
  19 {}
  20
  21 bool BitmapSymmetryCheck::check(Bitmap& rBitmap)
  22 {
  23     Bitmap::ScopedReadAccess aReadAccess(rBitmap);
  24     return checkImpl(aReadAccess.get());
  25 }
  26
  27 bool BitmapSymmetryCheck::checkImpl(BitmapReadAccess const * pReadAccess)
  28 {
  29     tools::Long nHeight = pReadAccess->Height();
  30     tools::Long nWidth = pReadAccess->Width();
  31
  32     tools::Long nHeightHalf = nHeight / 2;
  33     tools::Long nWidthHalf = nWidth / 2;
  34
  35     bool bHeightEven = (nHeight % 2) == 0;
  36     bool bWidthEven = (nWidth % 2) == 0;
  37
  38     for (tools::Long y = 0; y < nHeightHalf; ++y)
  39     {
  40         Scanline pScanlineRead = pReadAccess->GetScanline( y );
  41         Scanline pScanlineRead2 = pReadAccess->GetScanline( nHeight - y - 1 );
  42         for (tools::Long x = 0; x < nWidthHalf; ++x)
  43         {
  44             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, x))
  45             {
  46                 return false;
  47             }
  48             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
  49             {
  50                 return false;
  51             }
  52             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead2, nWidth - x - 1))
  53             {
  54                 return false;
  55             }
  56         }
  57     }
  58
  59     if (bWidthEven)
  60     {
  61         for (tools::Long y = 0; y < nHeightHalf; ++y)
  62         {
  63             if (pReadAccess->GetPixel(y, nWidthHalf) != pReadAccess->GetPixel(nHeight - y - 1, nWidthHalf))
  64             {
  65                 return false;
  66             }
  67         }
  68     }
  69
  70     if (bHeightEven)
  71     {
  72         Scanline pScanlineRead = pReadAccess->GetScanline( nHeightHalf );
  73         for (tools::Long x = 0; x < nWidthHalf; ++x)
  74         {
  75             if (pReadAccess->GetPixelFromData(pScanlineRead, x) != pReadAccess->GetPixelFromData(pScanlineRead, nWidth - x - 1))
  76             {
  77                 return false;
  78             }
  79         }
  80     }
  81
  82     return true;
  83 }
  84
  85
  86 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */