alpha.hxx

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#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 Bitmap& 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;
    SAL_DLLPRIVATE void             ImplSetBitmap( const Bitmap& rBitmap );
 
};
 
#endif // INCLUDED_VCL_ALPHA_HXX
 
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