alpha.hxx

Go to the documentation of this file.

/* -*- 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 .
 */
 
#ifndef INCLUDED_VCL_ALPHA_HXX
#define INCLUDED_VCL_ALPHA_HXX
 
#include <sal/config.h>
 
#include <utility>
 
#include <vcl/dllapi.h>
#include <vcl/bitmap.hxx>
 
class BitmapEx;
 
class VCL_DLLPUBLIC AlphaMask final : public Bitmap
{
public:
 
                AlphaMask();
    explicit    AlphaMask( const Bitmap& rBitmap );
                AlphaMask( const AlphaMask& rAlphaMask );
                AlphaMask( AlphaMask&& rAlphaMask );
    explicit    AlphaMask( const Size& rSizePixel, const sal_uInt8* pEraseTransparency = nullptr );
    virtual     ~AlphaMask() override;
 
    AlphaMask&  operator=( const Bitmap& rBitmap );
    AlphaMask&  operator=( const AlphaMask& rAlphaMask ) { return static_cast<AlphaMask&>( Bitmap::operator=( rAlphaMask ) ); }
    AlphaMask&  operator=( AlphaMask&& rAlphaMask ) noexcept { return static_cast<AlphaMask&>( Bitmap::operator=( std::move(rAlphaMask) ) ); }
    bool        operator==( const AlphaMask& rAlphaMask ) const { return Bitmap::operator==(rAlphaMask); }
    bool        operator!=( const AlphaMask& rAlphaMask ) const { return Bitmap::operator!=(rAlphaMask); }
 
    Bitmap const & GetBitmap() const;
 
    void        Erase( sal_uInt8 cTransparency );
    void        BlendWith(const AlphaMask& rOther);
 
    // check if alpha is used, returns true if at least one pixel has transparence
    bool        hasAlpha() const;
 
    BitmapReadAccess*  AcquireAlphaReadAccess() { return Bitmap::AcquireReadAccess(); }
    BitmapWriteAccess* AcquireAlphaWriteAccess() { return Bitmap::AcquireWriteAccess(); }
 
    void        ReleaseAccess( BitmapReadAccess* pAccess );
 
    typedef vcl::ScopedBitmapAccess<BitmapReadAccess, AlphaMask, &AlphaMask::AcquireAlphaReadAccess> ScopedReadAccess;
 
    using Bitmap::IsEmpty;
 
private:
    friend class BitmapEx;
    friend class ::OutputDevice;
    friend bool VCL_DLLPUBLIC ReadDIBBitmapEx(BitmapEx& rTarget, SvStream& rIStm, bool bFileHeader, bool bMSOFormat);
 
    SAL_DLLPRIVATE const Bitmap&    ImplGetBitmap() const;
 
};
 
#endif // INCLUDED_VCL_ALPHA_HXX
 
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */