vcl/source/bitmap/BitmapMaskToAlphaFilter.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 <basegfx/color/bcolortools.hxx>
  12
  13 #include <bitmap/BitmapWriteAccess.hxx>
  14 #include <bitmap/BitmapMaskToAlphaFilter.hxx>
  15
  16 /**
  17  * Convert a 1-bit mask to an alpha layer
  18  */
  19 BitmapEx BitmapMaskToAlphaFilter::execute(BitmapEx const& rBitmapEx) const
  20 {
  21     const Size aSize(rBitmapEx.GetSizePixel());
  22
  23     Bitmap aBitmap(rBitmapEx.GetBitmap());
  24     Bitmap aOutBitmap(aSize, vcl::PixelFormat::N8_BPP, &Bitmap::GetGreyPalette(256));
  25
  26     Bitmap::ScopedReadAccess pRead(aBitmap);
  27     BitmapScopedWriteAccess pWrite(aOutBitmap);
  28
  29     if (pRead && pWrite)
  30     {
  31         assert(pRead->HasPalette() && "only supposed to be called with 1-bit mask");
  32         assert(pRead->GetPaletteEntryCount() == 2);
  33         for (tools::Long nY = 0; nY < aSize.Height(); ++nY)
  34         {
  35             Scanline pScanline = pWrite->GetScanline(nY);
  36             Scanline pScanlineRead = pRead->GetScanline(nY);
  37             for (tools::Long nX = 0; nX < aSize.Width(); ++nX)
  38             {
  39                 BitmapColor aBmpColor = pRead->GetPixelFromData(pScanlineRead, nX);
  40                 if (aBmpColor == COL_BLACK)
  41                     aBmpColor = COL_BLACK;
  42                 else if (aBmpColor == COL_WHITE)
  43                     aBmpColor = COL_WHITE;
  44                 else if (aBmpColor == Color(0, 0, 1))
  45                     aBmpColor = COL_WHITE;
  46                 else
  47                     assert(false);
  48                 pWrite->SetPixelOnData(pScanline, nX, aBmpColor);
  49             }
  50         }
  51     }
  52     pWrite.reset();
  53     pRead.reset();
  54
  55     return BitmapEx(aOutBitmap);
  56 }
  57
  58 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */