vcl/source/bitmap/BitmapAlphaClampFilter.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/bitmapex.hxx>
  12 #include <vcl/BitmapAlphaClampFilter.hxx>
  13
  14 #include <bitmap/BitmapWriteAccess.hxx>
  15
  16 BitmapEx BitmapAlphaClampFilter::execute(BitmapEx const& rBitmapEx) const
  17 {
  18     if (!rBitmapEx.IsAlpha())
  19         return rBitmapEx;
  20
  21     AlphaMask aBitmapAlpha(rBitmapEx.GetAlpha());
  22     {
  23         AlphaScopedWriteAccess pWriteAlpha(aBitmapAlpha);
  24         const Size aSize(rBitmapEx.GetSizePixel());
  25
  26         for (tools::Long nY = 0; nY < aSize.Height(); ++nY)
  27         {
  28             Scanline pScanAlpha = pWriteAlpha->GetScanline(nY);
  29
  30             for (tools::Long nX = 0; nX < aSize.Width(); ++nX)
  31             {
  32                 BitmapColor aBitmapAlphaValue(pWriteAlpha->GetPixelFromData(pScanAlpha, nX));
  33                 if (aBitmapAlphaValue.GetIndex() > mcThreshold)
  34                 {
  35                     aBitmapAlphaValue.SetIndex(255);
  36                     pWriteAlpha->SetPixelOnData(pScanAlpha, nX, aBitmapAlphaValue);
  37                 }
  38             }
  39         }
  40     }
  41
  42     return BitmapEx(rBitmapEx.GetBitmap(), aBitmapAlpha);
  43 }
  44
  45 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */