bitmapbackbuffer.cxx

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#include <sal/config.h>
 
#include <osl/diagnose.h>
#include <vcl/bitmapex.hxx>
#include <vcl/svapp.hxx>
 
#include "bitmapbackbuffer.hxx"
#include "impltools.hxx"
 
namespace vclcanvas
{
    BitmapBackBuffer::BitmapBackBuffer( const BitmapEx&         rBitmap,
                                        const OutputDevice&     rRefDevice ) :
        maBitmap( rBitmap ),
        mpVDev( nullptr ),
        mrRefDevice( rRefDevice ),
        mbBitmapContentIsCurrent( false ),
        mbVDevContentIsCurrent( false )
    {
    }
 
    BitmapBackBuffer::~BitmapBackBuffer()
    {
        // make sure solar mutex is held on deletion (other methods
        // are supposed to be called with already locked solar mutex)
        SolarMutexGuard aGuard;
 
        mpVDev.disposeAndClear();
    }
 
    OutputDevice& BitmapBackBuffer::getOutDev()
    {
        createVDev();
        updateVDev();
        return *mpVDev;
    }
 
    const OutputDevice& BitmapBackBuffer::getOutDev() const
    {
        createVDev();
        updateVDev();
        return *mpVDev;
    }
 
    void BitmapBackBuffer::clear()
    {
        // force current content to bitmap, make all transparent white
        getBitmapReference().Erase(COL_TRANSPARENT);
    }
 
    BitmapEx& BitmapBackBuffer::getBitmapReference()
    {
        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
                    "BitmapBackBuffer::getBitmapReference(): Both bitmap and VDev are valid?!" );
 
        if( mbVDevContentIsCurrent && mpVDev )
        {
            // VDev content is more current than bitmap - copy contents before!
            mpVDev->EnableMapMode( false );
            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
            const Point aEmptyPoint;
            *maBitmap = mpVDev->GetBitmapEx( aEmptyPoint,
                                             mpVDev->GetOutputSizePixel() );
        }
 
        // client queries bitmap, and will possibly alter content -
        // next time, VDev needs to be updated
        mbBitmapContentIsCurrent = true;
        mbVDevContentIsCurrent   = false;
 
        return *maBitmap;
    }
 
    Size BitmapBackBuffer::getBitmapSizePixel() const
    {
        Size aSize = maBitmap->GetSizePixel();
 
        if( mbVDevContentIsCurrent && mpVDev )
        {
            mpVDev->EnableMapMode( false );
            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
            aSize = mpVDev->GetOutputSizePixel();
        }
 
        return aSize;
    }
 
    void BitmapBackBuffer::createVDev() const
    {
        if( mpVDev )
            return;
 
        // VDev not yet created, do it now. Create an alpha-VDev,
        // if bitmap has transparency.
        mpVDev = maBitmap->IsAlpha() ?
            VclPtr<VirtualDevice>::Create( mrRefDevice, DeviceFormat::WITH_ALPHA ) :
            VclPtr<VirtualDevice>::Create( mrRefDevice );
 
        OSL_ENSURE( mpVDev,
                    "BitmapBackBuffer::createVDev(): Unable to create VirtualDevice" );
 
        mpVDev->SetOutputSizePixel( maBitmap->GetSizePixel() );
 
        tools::SetDefaultDeviceAntiAliasing( mpVDev );
    }
 
    void BitmapBackBuffer::updateVDev() const
    {
        OSL_ENSURE( !mbBitmapContentIsCurrent || !mbVDevContentIsCurrent,
                    "BitmapBackBuffer::updateVDev(): Both bitmap and VDev are valid?!" );
 
        if( mpVDev && mbBitmapContentIsCurrent )
        {
            // fill with bitmap content
            mpVDev->EnableMapMode( false );
            mpVDev->SetAntialiasing( AntialiasingFlags::Enable );
            const Point aEmptyPoint;
            mpVDev->DrawBitmapEx( aEmptyPoint, *maBitmap );
        }
 
        // canvas queried the VDev, and will possibly paint into
        // it. Next time, bitmap must be updated
        mbBitmapContentIsCurrent = false;
        mbVDevContentIsCurrent   = true;
    }
}
 
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