vcl/source/bitmap/BitmapPopArtFilter.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 <tools/solar.h>
  12
  13 #include <vcl/bitmap/BitmapPopArtFilter.hxx>
  14 #include <vcl/BitmapWriteAccess.hxx>
  15
  16 BitmapEx BitmapPopArtFilter::execute(BitmapEx const& rBitmapEx) const
  17 {
  18     Bitmap aBitmap(rBitmapEx.GetBitmap());
  19
  20     bool bConvert = isPalettePixelFormat(aBitmap.getPixelFormat())
  21                     || aBitmap.Convert(BmpConversion::N8BitColors);
  22
  23     if (!bConvert)
  24         return BitmapEx();
  25
  26     BitmapScopedWriteAccess pWriteAcc(aBitmap);
  27
  28     if (!pWriteAcc)
  29         return BitmapEx();
  30
  31     const sal_Int32 nWidth = pWriteAcc->Width();
  32     const sal_Int32 nHeight = pWriteAcc->Height();
  33     const sal_uInt16 nEntryCount = 1 << pWriteAcc->GetBitCount();
  34     sal_uInt16 n = 0;
  35     std::vector<PopArtEntry> aPopArtTable(nEntryCount);
  36
  37     for (n = 0; n < nEntryCount; n++)
  38     {
  39         PopArtEntry& rEntry = aPopArtTable[n];
  40         rEntry.mnIndex = n;
  41         rEntry.mnCount = 0;
  42     }
  43
  44     // get pixel count for each palette entry
  45     for (sal_Int32 nY = 0; nY < nHeight; nY++)
  46     {
  47         Scanline pScanline = pWriteAcc->GetScanline(nY);
  48         for (sal_Int32 nX = 0; nX < nWidth; nX++)
  49         {
  50             aPopArtTable[pWriteAcc->GetIndexFromData(pScanline, nX)].mnCount++;
  51             assert(aPopArtTable[pWriteAcc->GetIndexFromData(pScanline, nX)].mnCount != 0);
  52         }
  53     }
  54
  55     // sort table
  56     std::sort(
  57         aPopArtTable.begin(), aPopArtTable.end(),
  58         [](const PopArtEntry& lhs, const PopArtEntry& rhs) { return lhs.mnCount > rhs.mnCount; });
  59
  60     // get last used entry
  61     sal_uInt16 nFirstEntry;
  62     sal_uInt16 nLastEntry = 0;
  63
  64     for (n = 0; n < nEntryCount; n++)
  65     {
  66         if (aPopArtTable[n].mnCount)
  67             nLastEntry = n;
  68     }
  69
  70     // rotate palette (one entry)
  71     const BitmapColor aFirstCol(pWriteAcc->GetPaletteColor(aPopArtTable[0].mnIndex));
  72
  73     for (nFirstEntry = 0; nFirstEntry < nLastEntry; nFirstEntry++)
  74     {
  75         pWriteAcc->SetPaletteColor(
  76             aPopArtTable[nFirstEntry].mnIndex,
  77             pWriteAcc->GetPaletteColor(aPopArtTable[nFirstEntry + 1].mnIndex));
  78     }
  79
  80     pWriteAcc->SetPaletteColor(aPopArtTable[nLastEntry].mnIndex, aFirstCol);
  81
  82     // cleanup
  83     pWriteAcc.reset();
  84
  85     return BitmapEx(aBitmap);
  86 }
  87
  88 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */