vcl/source/bitmap/BitmapDisabledImageFilter.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/BitmapWriteAccess.hxx>
  12 #include <bitmap/BitmapDisabledImageFilter.hxx>
  13
  14 BitmapEx BitmapDisabledImageFilter::execute(BitmapEx const& rBitmapEx) const
  15 {
  16     const Size aSize(rBitmapEx.GetSizePixel());
  17
  18     // keep disable image at same depth as original where possible, otherwise
  19     // use 8 bit
  20     auto ePixelFormat = rBitmapEx.getPixelFormat();
  21     if (sal_uInt16(ePixelFormat) < 8)
  22         ePixelFormat = vcl::PixelFormat::N8_BPP;
  23
  24     const BitmapPalette* pPal
  25         = vcl::isPalettePixelFormat(ePixelFormat) ? &Bitmap::GetGreyPalette(256) : nullptr;
  26     Bitmap aGrey(aSize, ePixelFormat, pPal);
  27     BitmapScopedWriteAccess pGrey(aGrey);
  28
  29     const Bitmap& aReadBitmap(rBitmapEx.GetBitmap());
  30     BitmapScopedReadAccess pRead(aReadBitmap);
  31     if (pRead && pGrey)
  32     {
  33         for (sal_Int32 nY = 0; nY < sal_Int32(aSize.Height()); ++nY)
  34         {
  35             Scanline pGreyScan = pGrey->GetScanline(nY);
  36             Scanline pReadScan = pRead->GetScanline(nY);
  37
  38             for (sal_Int32 nX = 0; nX < sal_Int32(aSize.Width()); ++nX)
  39             {
  40                 // Get the luminance from RGB color and remap the value from 0-255 to 160-224
  41                 const BitmapColor aColor = pRead->GetPixelFromData(pReadScan, nX);
  42                 sal_uInt8 nLum(aColor.GetLuminance() / 4 + 160);
  43                 BitmapColor aGreyValue(ColorAlpha, nLum, nLum, nLum, aColor.GetAlpha());
  44                 pGrey->SetPixelOnData(pGreyScan, nX, aGreyValue);
  45             }
  46         }
  47     }
  48
  49     if (rBitmapEx.IsAlpha())
  50         return BitmapEx(aGrey, rBitmapEx.GetAlphaMask());
  51
  52     return BitmapEx(aGrey);
  53 }
  54
  55 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */