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 <vcl/bitmap.hxx>
  12 #include <vcl/bitmapex.hxx>
  13 #include <vcl/BitmapPopArtFilter.hxx>
  14
  15 #include <bitmap/BitmapWriteAccess.hxx>
  16
  17 BitmapEx BitmapPopArtFilter::execute(BitmapEx const& rBitmapEx) const
  18 {
  19     Bitmap aBitmap(rBitmapEx.GetBitmap());
  20
  21     bool bRet = isPalettePixelFormat(aBitmap.getPixelFormat())
  22                 || aBitmap.Convert(BmpConversion::N8BitColors);
  23
  24     if (bRet)
  25     {
  26         bRet = false;
  27
  28         BitmapScopedWriteAccess pWriteAcc(aBitmap);
  29
  30         if (pWriteAcc)
  31         {
  32             const tools::Long nWidth = pWriteAcc->Width();
  33             const tools::Long nHeight = pWriteAcc->Height();
  34             const int nEntryCount = 1 << pWriteAcc->GetBitCount();
  35             int n = 0;
  36             std::vector<PopArtEntry> aPopArtTable(nEntryCount);
  37
  38             for (n = 0; n < nEntryCount; n++)
  39             {
  40                 PopArtEntry& rEntry = aPopArtTable[n];
  41                 rEntry.mnIndex = static_cast<sal_uInt16>(n);
  42                 rEntry.mnCount = 0;
  43             }
  44
  45             // get pixel count for each palette entry
  46             for (tools::Long nY = 0; nY < nHeight; nY++)
  47             {
  48                 Scanline pScanline = pWriteAcc->GetScanline(nY);
  49                 for (tools::Long nX = 0; nX < nWidth; nX++)
  50                 {
  51                     aPopArtTable[pWriteAcc->GetIndexFromData(pScanline, nX)].mnCount++;
  52                 }
  53             }
  54
  55             // sort table
  56             std::sort(aPopArtTable.begin(), aPopArtTable.end(),
  57                       [](const PopArtEntry& lhs, const PopArtEntry& rhs) {
  58                           return lhs.mnCount < rhs.mnCount;
  59                       });
  60
  61             // get last used entry
  62             sal_uLong nFirstEntry;
  63             sal_uLong nLastEntry = 0;
  64
  65             for (n = 0; n < nEntryCount; n++)
  66             {
  67                 if (aPopArtTable[n].mnCount)
  68                     nLastEntry = n;
  69             }
  70
  71             // rotate palette (one entry)
  72             const BitmapColor aFirstCol(pWriteAcc->GetPaletteColor(
  73                 sal::static_int_cast<sal_uInt16>(aPopArtTable[0].mnIndex)));
  74
  75             for (nFirstEntry = 0; nFirstEntry < nLastEntry; nFirstEntry++)
  76             {
  77                 pWriteAcc->SetPaletteColor(
  78                     sal::static_int_cast<sal_uInt16>(aPopArtTable[nFirstEntry].mnIndex),
  79                     pWriteAcc->GetPaletteColor(
  80                         sal::static_int_cast<sal_uInt16>(aPopArtTable[nFirstEntry + 1].mnIndex)));
  81             }
  82
  83             pWriteAcc->SetPaletteColor(
  84                 sal::static_int_cast<sal_uInt16>(aPopArtTable[nLastEntry].mnIndex), aFirstCol);
  85
  86             // cleanup
  87             pWriteAcc.reset();
  88             bRet = true;
  89         }
  90     }
  91
  92     if (bRet)
  93         return BitmapEx(aBitmap);
  94
  95     return BitmapEx();
  96 }
  97
  98 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */