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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#include <config_features.h>
#include <tools/color.hxx>
#include <vcl/alpha.hxx>
#include <vcl/BitmapWriteAccess.hxx>
#include <salinst.hxx>
#include <svdata.hxx>
#include <salbmp.hxx>
#include <sal/log.hxx>
#if HAVE_FEATURE_SKIA
#include <vcl/skia/SkiaHelper.hxx>
#endif
AlphaMask::AlphaMask() = default;
AlphaMask::AlphaMask( const Bitmap& rBitmap ) :
maBitmap( rBitmap )
{
if ( !rBitmap.IsEmpty() )
maBitmap.Convert( BmpConversion::N8BitNoConversion );
#if HAVE_FEATURE_SKIA
// Related tdf#156866 force snapshot of alpha mask when using Skia
// In release builds, tdf#156629 and tdf#156630 reappear in many
// cases because a BitmapInfoAccess is in a debug block. So, instead
// of relying on other code to a create a BitmapInfoAccess instance,
// create one here to force the alpha mask to handle any pending
// scaling and make the alpha mask immutable.
else if ( SkiaHelper::isVCLSkiaEnabled() )
BitmapInfoAccess aInfoAccess( maBitmap );
#endif
assert( (IsEmpty() || maBitmap.getPixelFormat() == vcl::PixelFormat::N8_BPP) && "alpha bitmap should be 8bpp" );
assert( (IsEmpty() || maBitmap.HasGreyPalette8Bit()) && "alpha bitmap should have greyscale palette" );
}
AlphaMask::AlphaMask( const AlphaMask& ) = default;
AlphaMask::AlphaMask( AlphaMask&& ) = default;
AlphaMask::AlphaMask( const Size& rSizePixel, const sal_uInt8* pEraseTransparency )
: maBitmap(rSizePixel, vcl::PixelFormat::N8_BPP, &Bitmap::GetGreyPalette(256))
{
if( pEraseTransparency )
{
sal_uInt8 nAlpha = 255 - *pEraseTransparency;
maBitmap.Erase( Color( nAlpha, nAlpha, nAlpha ) );
}
else
maBitmap.Erase( COL_ALPHA_OPAQUE );
}
AlphaMask::~AlphaMask() = default;
AlphaMask& AlphaMask::operator=( const Bitmap& rBitmap )
{
maBitmap = rBitmap;
if( !rBitmap.IsEmpty() )
maBitmap.Convert( BmpConversion::N8BitNoConversion );
assert( maBitmap.getPixelFormat() == vcl::PixelFormat::N8_BPP && "alpha bitmap should be 8bpp" );
assert( maBitmap.HasGreyPalette8Bit() && "alpha bitmap should have greyscale palette" );
return *this;
}
void AlphaMask::Erase( sal_uInt8 cTransparency )
{
sal_uInt8 nAlpha = 255 - cTransparency;
maBitmap.Erase( Color( nAlpha, nAlpha, nAlpha ) );
}
void AlphaMask::BlendWith(const AlphaMask& rOther)
{
std::shared_ptr<SalBitmap> xImpBmp(ImplGetSVData()->mpDefInst->CreateSalBitmap());
if (xImpBmp->Create(*maBitmap.ImplGetSalBitmap()) && xImpBmp->AlphaBlendWith(*rOther.maBitmap.ImplGetSalBitmap()))
{
maBitmap.ImplSetSalBitmap(xImpBmp);
assert( maBitmap.getPixelFormat() == vcl::PixelFormat::N8_BPP && "alpha bitmap should be 8bpp" );
assert( maBitmap.HasGreyPalette8Bit() && "alpha bitmap should have greyscale palette" );
return;
}
BitmapScopedReadAccess pOtherAcc(rOther);
BitmapScopedWriteAccess pAcc(*this);
assert (pOtherAcc && pAcc && pOtherAcc->GetBitCount() == 8 && pAcc->GetBitCount() == 8 && "cannot BlendWith this combination");
if (!(pOtherAcc && pAcc && pOtherAcc->GetBitCount() == 8 && pAcc->GetBitCount() == 8))
{
SAL_WARN("vcl", "cannot BlendWith this combination");
return;
}
const tools::Long nHeight = std::min(pOtherAcc->Height(), pAcc->Height());
const tools::Long nWidth = std::min(pOtherAcc->Width(), pAcc->Width());
for (tools::Long y = 0; y < nHeight; ++y)
{
Scanline scanline = pAcc->GetScanline( y );
ConstScanline otherScanline = pOtherAcc->GetScanline( y );
for (tools::Long x = 0; x < nWidth; ++x)
{
// Use sal_uInt16 for following multiplication
const sal_uInt16 nGrey1 = *scanline;
const sal_uInt16 nGrey2 = *otherScanline;
// Awkward calculation because the original used transparency, and to replicate
// the logic we need to translate into transparency, perform the original logic,
// then translate back to alpha.
// The original looked like:
// auto tmp = nGrey1 + nGrey2 - (nGrey1 * nGrey2 / 255)
// which, when converted to using alpha looks like
// auto tmp = 255 - ((255 - nGrey1) + (255 - nGrey2) - (255 - nGrey1) * (255 - nGrey2) / 255);
// which then simplifies to:
auto tmp = nGrey1 * nGrey2 / 255;
*scanline = static_cast<sal_uInt8>(tmp);
++scanline;
++otherScanline;
}
}
pAcc.reset();
assert( maBitmap.getPixelFormat() == vcl::PixelFormat::N8_BPP && "alpha bitmap should be 8bpp" );
assert( maBitmap.HasGreyPalette8Bit() && "alpha bitmap should have greyscale palette" );
}
bool AlphaMask::hasAlpha() const
{
// no content, no alpha
if(IsEmpty())
return false;
BitmapScopedReadAccess pAcc(*this);
const tools::Long nHeight(pAcc->Height());
const tools::Long nWidth(pAcc->Width());
// no content, no alpha
if(0 == nHeight || 0 == nWidth)
return false;
for (tools::Long y = 0; y < nHeight; ++y)
{
for (tools::Long x = 0; x < nWidth; ++x)
{
if (255 != pAcc->GetColor(y, x).GetRed())
{
return true;
}
}
}
return false;
}
bool AlphaMask::AlphaCombineOr(const AlphaMask& rMask)
{
BitmapScopedReadAccess pMaskAcc(rMask);
BitmapScopedWriteAccess pAcc(*this);
if (!pMaskAcc || !pAcc)
return false;
assert (pMaskAcc->GetBitCount() == 8 && pAcc->GetBitCount() == 8);
const tools::Long nWidth = std::min(pMaskAcc->Width(), pAcc->Width());
const tools::Long nHeight = std::min(pMaskAcc->Height(), pAcc->Height());
for (tools::Long nY = 0; nY < nHeight; nY++)
{
Scanline pScanline = pAcc->GetScanline(nY);
ConstScanline pScanlineMask = pMaskAcc->GetScanline(nY);
for (tools::Long nX = 0; nX < nWidth; nX++)
{
if (*pScanlineMask != 255 || *pScanline != 255)
*pScanline = 0;
else
*pScanline = 255;
++pScanline;
++pScanlineMask;
}
}
return true;
}
bool AlphaMask::Invert()
{
if (IsEmpty())
return false;
bool b = maBitmap.Invert();
assert( maBitmap.getPixelFormat() == vcl::PixelFormat::N8_BPP && "alpha bitmap should be 8bpp" );
assert( maBitmap.HasGreyPalette8Bit() && "alpha bitmap should have greyscale palette" );
return b;
}
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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