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 <bitmapwriteaccess.hxx>
  16
  17 BitmapEx BitmapPopArtFilter::execute(BitmapEx const& rBitmapEx) const
  18 {
  19     Bitmap aBitmap(rBitmapEx.GetBitmap());
  20
  21     bool bRet = (aBitmap.GetBitCount() <= 8) || aBitmap.Convert(BmpConversion::N8BitColors);
  22
  23     if (bRet)
  24     {
  25         bRet = false;
  26
  27         BitmapScopedWriteAccess pWriteAcc(aBitmap);
  28
  29         if (pWriteAcc)
  30         {
  31             const long nWidth = pWriteAcc->Width();
  32             const long nHeight = pWriteAcc->Height();
  33             const int nEntryCount = 1 << pWriteAcc->GetBitCount();
  34             int 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 = static_cast<sal_uInt16>(n);
  41                 rEntry.mnCount = 0;
  42             }
  43
  44             // get pixel count for each palette entry
  45             for (long nY = 0; nY < nHeight; nY++)
  46             {
  47                 Scanline pScanline = pWriteAcc->GetScanline(nY);
  48                 for (long nX = 0; nX < nWidth; nX++)
  49                 {
  50                     aPopArtTable[pWriteAcc->GetIndexFromData(pScanline, nX)].mnCount++;
  51                 }
  52             }
  53
  54             // sort table
  55             std::sort(aPopArtTable.begin(), aPopArtTable.end(),
  56                       [](const PopArtEntry& lhs, const PopArtEntry& rhs) {
  57                           return lhs.mnCount < rhs.mnCount;
  58                       });
  59
  60             // get last used entry
  61             sal_uLong nFirstEntry;
  62             sal_uLong 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(
  72                 sal::static_int_cast<sal_uInt16>(aPopArtTable[0].mnIndex)));
  73
  74             for (nFirstEntry = 0; nFirstEntry < nLastEntry; nFirstEntry++)
  75             {
  76                 pWriteAcc->SetPaletteColor(
  77                     sal::static_int_cast<sal_uInt16>(aPopArtTable[nFirstEntry].mnIndex),
  78                     pWriteAcc->GetPaletteColor(
  79                         sal::static_int_cast<sal_uInt16>(aPopArtTable[nFirstEntry + 1].mnIndex)));
  80             }
  81
  82             pWriteAcc->SetPaletteColor(
  83                 sal::static_int_cast<sal_uInt16>(aPopArtTable[nLastEntry].mnIndex), aFirstCol);
  84
  85             // cleanup
  86             pWriteAcc.reset();
  87             bRet = true;
  88         }
  89     }
  90
  91     if (bRet)
  92         return BitmapEx(aBitmap);
  93
  94     return BitmapEx();
  95 }
  96
  97 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */