vcl/source/bitmap/BitmapArithmeticBlendFilter.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 <comphelper/diagnose_ex.hxx>
  12
  13 #include <vcl/bitmap/BitmapArithmeticBlendFilter.hxx>
  14 #include <vcl/BitmapWriteAccess.hxx>
  15 #include <vcl/BitmapTools.hxx>
  16
  17 BitmapArithmeticBlendFilter::BitmapArithmeticBlendFilter(BitmapEx const& rBitmapEx2, double nK1,
  18                                                          double nK2, double nK3, double nK4)
  19     : maBitmapEx2(rBitmapEx2)
  20     , mnK1(nK1)
  21     , mnK2(nK2)
  22     , mnK3(nK3)
  23     , mnK4(nK4)
  24 {
  25 }
  26
  27 BitmapArithmeticBlendFilter::~BitmapArithmeticBlendFilter() {}
  28
  29 static sal_uInt8 lcl_calculate(const sal_uInt8 cColor, const sal_uInt8 cColor2, const double nK1,
  30                                const double nK2, const double nK3, const double nK4)
  31 {
  32     const double i1 = cColor / 255.0;
  33     const double i2 = cColor2 / 255.0;
  34     const double result = nK1 * i1 * i2 + nK2 * i1 + nK3 * i2 + nK4;
  35
  36     return std::clamp(result, 0.0, 1.0) * 255.0;
  37 }
  38
  39 BitmapEx BitmapArithmeticBlendFilter::execute(BitmapEx const& rBitmapEx) const
  40 {
  41     if (rBitmapEx.IsEmpty() || maBitmapEx2.IsEmpty())
  42         return BitmapEx();
  43
  44     const Size aSize = rBitmapEx.GetBitmap().GetSizePixel();
  45     const Size aSize2 = maBitmapEx2.GetBitmap().GetSizePixel();
  46     const sal_Int32 nHeight = std::min(aSize.getHeight(), aSize2.getHeight());
  47     const sal_Int32 nWidth = std::min(aSize.getWidth(), aSize2.getWidth());
  48
  49     Bitmap aDstBitmap(Size(nWidth, nHeight), vcl::PixelFormat::N24_BPP);
  50     Bitmap aDstAlpha(AlphaMask(Size(nWidth, nHeight)).GetBitmap());
  51
  52     BitmapScopedWriteAccess pWriteAccess(aDstBitmap);
  53     BitmapScopedWriteAccess pAlphaWriteAccess(aDstAlpha);
  54
  55     for (tools::Long y = 0; y < nHeight; ++y)
  56     {
  57         Scanline pScanline = pWriteAccess->GetScanline(y);
  58         Scanline pScanAlpha = pAlphaWriteAccess->GetScanline(y);
  59
  60         for (tools::Long x = 0; x < nWidth; ++x)
  61         {
  62             const BitmapColor i1 = vcl::bitmap::premultiply(rBitmapEx.GetPixelColor(x, y));
  63             const BitmapColor i2 = vcl::bitmap::premultiply(maBitmapEx2.GetPixelColor(x, y));
  64
  65             const sal_uInt8 r(lcl_calculate(i1.GetRed(), i2.GetRed(), mnK1, mnK2, mnK3, mnK4));
  66             const sal_uInt8 g(lcl_calculate(i1.GetGreen(), i2.GetGreen(), mnK1, mnK2, mnK3, mnK4));
  67             const sal_uInt8 b(lcl_calculate(i1.GetBlue(), i2.GetBlue(), mnK1, mnK2, mnK3, mnK4));
  68             const sal_uInt8 a(lcl_calculate(i1.GetAlpha(), i2.GetAlpha(), mnK1, mnK2, mnK3, mnK4));
  69
  70             pWriteAccess->SetPixelOnData(
  71                 pScanline, x, vcl::bitmap::unpremultiply(BitmapColor(ColorAlpha, r, g, b, a)));
  72             pAlphaWriteAccess->SetPixelOnData(pScanAlpha, x, BitmapColor(a));
  73         }
  74     }
  75
  76     pWriteAccess.reset();
  77     pAlphaWriteAccess.reset();
  78
  79     return BitmapEx(aDstBitmap, AlphaMask(aDstAlpha));
  80 }
  81
  82 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */