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/bitmapaccess.hxx>
  12
  13 #include <bitmapwriteaccess.hxx>
  14 #include <BitmapDisabledImageFilter.hxx>
  15
  16 BitmapEx BitmapDisabledImageFilter::execute(BitmapEx const& rBitmapEx) const
  17 {
  18     const Size aSize(rBitmapEx.GetSizePixel());
  19
  20     // keep disable image at same depth as original where possible, otherwise
  21     // use 8 bit
  22     sal_uInt16 nBitCount = rBitmapEx.GetBitCount();
  23     if (nBitCount < 8)
  24         nBitCount = 8;
  25
  26     const BitmapPalette* pPal = nBitCount == 8 ? &Bitmap::GetGreyPalette(256) : nullptr;
  27     Bitmap aGrey(aSize, nBitCount, pPal);
  28     BitmapScopedWriteAccess pGrey(aGrey);
  29
  30     BitmapEx aReturnBitmap;
  31     Bitmap aReadBitmap(rBitmapEx.GetBitmap());
  32     Bitmap::ScopedReadAccess pRead(aReadBitmap);
  33     if (pRead && pGrey)
  34     {
  35         for (long nY = 0; nY < aSize.Height(); ++nY)
  36         {
  37             Scanline pGreyScan = pGrey->GetScanline(nY);
  38             Scanline pReadScan = pRead->GetScanline(nY);
  39
  40             for (long nX = 0; nX < aSize.Width(); ++nX)
  41             {
  42                 // Get the luminance from RGB color and remap the value from 0-255 to 160-224
  43                 const BitmapColor aColor = pRead->GetPixelFromData(pReadScan, nX);
  44                 sal_uInt8 nLum(aColor.GetLuminance() / 4 + 160);
  45                 BitmapColor aGreyValue(nLum, nLum, nLum, aColor.GetAlpha());
  46                 pGrey->SetPixelOnData(pGreyScan, nX, aGreyValue);
  47             }
  48         }
  49     }
  50
  51     if (rBitmapEx.IsTransparent())
  52     {
  53         aReturnBitmap = BitmapEx(aGrey, rBitmapEx.GetAlpha());
  54     }
  55     else
  56         aReturnBitmap = BitmapEx(aGrey);
  57
  58     return aReturnBitmap;
  59 }
  60
  61 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */