Inheritance diagram for osgEarth::Features::BufferFilter:

Collaboration diagram for osgEarth::Features::BufferFilter:

Public Member Functions
	BufferFilter ()
	BufferFilter (const BufferFilter &rhs)
optional< double > &	distance ()
const optional< double > &	distance () const
int	numQuadrantSegments () const
int &	numQuadrantSegments ()
const Stroke::LineCapStyle &	capStyle () const
Stroke::LineCapStyle &	capStyle ()
virtual FilterContext	push (FeatureList &input, FilterContext &context)
Static Public Member Functions
static bool	isSupported ()
Protected Attributes
optional< double >	_distance
int	_numQuadSegs
Stroke::LineCapStyle	_capStyle

Detailed Description

The buffer geometry operation takes each input vector shape and applies morphological dilation or erosion to it. (see http://en.wikipedia.org/wiki/Morphological_image_processing)

The buffer distance determines which operation to use:

A positive distance dilates the shape (expands it). A negative distance erodes the shape (shrinks it).

Note: buffering always converts the input vector data into polygons.

Definition at line 46 of file BufferFilter.

Constructor & Destructor Documentation

BufferFilter::BufferFilter ( )

Definition at line 41 of file BufferFilter.cpp.

                           :
_distance   ( 1.0 ),
_numQuadSegs( 0 ),
_capStyle   ( Stroke::LINECAP_DEFAULT )
{
    //NOP
}

BufferFilter::BufferFilter ( const BufferFilter & rhs )

Definition at line 49 of file BufferFilter.cpp.

                                                    :
_distance   ( rhs._distance ),
_numQuadSegs( rhs._numQuadSegs ),
_capStyle   ( rhs._capStyle )
{
    //NOP
}

Member Function Documentation

const Stroke::LineCapStyle& osgEarth::Features::BufferFilter::capStyle ( ) const [inline]

Definition at line 69 of file BufferFilter.

{ return _capStyle; }

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Stroke::LineCapStyle& osgEarth::Features::BufferFilter::capStyle ( ) [inline]

Definition at line 70 of file BufferFilter.

{ return _capStyle; }

optional<double>& osgEarth::Features::BufferFilter::distance ( ) [inline]

Definition at line 60 of file BufferFilter.

{ return _distance; }

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const optional<double>& osgEarth::Features::BufferFilter::distance ( ) const [inline]

Definition at line 61 of file BufferFilter.

{ return _distance; }

bool BufferFilter::isSupported ( ) [static]

Definition at line 26 of file BufferFilter.cpp.

{
#ifdef OSGEARTH_HAVE_GEOS
    static bool s_isSupported = true;
#else
    static bool s_isSupported = false;
#endif

    return s_isSupported;
}

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int osgEarth::Features::BufferFilter::numQuadrantSegments ( ) const [inline]

Definition at line 65 of file BufferFilter.

{ return _numQuadSegs; }

int& osgEarth::Features::BufferFilter::numQuadrantSegments ( ) [inline]

Definition at line 66 of file BufferFilter.

{ return _numQuadSegs; }

FilterContext BufferFilter::push	(	FeatureList &	input,
		FilterContext &	context
	)		`[virtual]`

Implements osgEarth::Features::FeatureFilter.

Definition at line 58 of file BufferFilter.cpp.

{
    if ( !isSupported() )
    {
        OE_WARN << "BufferFilter support not enabled - please compile osgEarth with GEOS" << std::endl;
        return context;
    }

    //OE_NOTICE << "Buffer: input = " << input.size() << " features" << std::endl;
    for( FeatureList::iterator i = input.begin(); i != input.end(); ++i )
    {
        Feature* input = i->get();
        if ( !input || !input->getGeometry() )
            continue;

        osg::ref_ptr<Symbology::Geometry> output;

        Symbology::BufferParameters params;
        
        params._capStyle =
                _capStyle == Stroke::LINECAP_ROUND  ? Symbology::BufferParameters::CAP_ROUND :
                _capStyle == Stroke::LINECAP_SQUARE ? Symbology::BufferParameters::CAP_SQUARE :
                _capStyle == Stroke::LINECAP_BUTT   ? Symbology::BufferParameters::CAP_FLAT :
                Symbology::BufferParameters::CAP_SQUARE;

        params._cornerSegs = _numQuadSegs;

        if ( input->getGeometry()->buffer( _distance.value(), output, params ) )
        {
            input->setGeometry( output.get() );
        }
    }

    return context;
}