Inheritance diagram for osgEarth::Features::ResampleFilter:

Collaboration diagram for osgEarth::Features::ResampleFilter:

Public Types
enum	ResampleMode { RESAMPLE_LINEAR, RESAMPLE_GREATCIRCLE, RESAMPLE_RHUMB }
Public Member Functions
	ResampleFilter ()
	ResampleFilter (double minLength, double maxLength)
optional< double > &	minLength ()
const optional< double > &	minLength () const
optional< double > &	maxLength ()
const optional< double > &	maxLength () const
optional< double > &	perturbationThreshold ()
const optional< double > &	perturbationThreshold () const
optional< ResampleMode > &	resampleMode ()
const optional< ResampleMode > &	resampleMode () const
virtual FilterContext	push (FeatureList &input, FilterContext &context)
Static Public Member Functions
static bool	isSupported ()
Protected Member Functions
bool	push (Feature *input, FilterContext &context)
Protected Attributes
optional< double >	_minLen
optional< double >	_maxLen
optional< double >	_perturbThresh
optional< ResampleMode >	_resampleMode

Detailed Description

This filter will resample line segments so they are between the min and max specified length.

Definition at line 36 of file ResampleFilter.

Member Enumeration Documentation

enum osgEarth::Features::ResampleFilter::ResampleMode

Enumerator:

RESAMPLE_LINEAR
RESAMPLE_GREATCIRCLE
RESAMPLE_RHUMB

Definition at line 59 of file ResampleFilter.

        {
            RESAMPLE_LINEAR,
            RESAMPLE_GREATCIRCLE,
            RESAMPLE_RHUMB
        };

Constructor & Destructor Documentation

ResampleFilter::ResampleFilter ( )

Definition at line 36 of file ResampleFilter.cpp.

                               :
_minLen( 0 ),
_maxLen( DBL_MAX ),
_perturbThresh( 0 ),
_resampleMode(RESAMPLE_LINEAR)
{
    //NOP
}

ResampleFilter::ResampleFilter	(	double	minLength,
		double	maxLength
	)

Definition at line 45 of file ResampleFilter.cpp.

                                                             :
_minLen( minLen ),
_maxLen( maxLen ),
_perturbThresh( 0 ),
_resampleMode(RESAMPLE_LINEAR)
{
    // NOP
}

Member Function Documentation

bool ResampleFilter::isSupported ( ) [static]

Definition at line 31 of file ResampleFilter.cpp.

{
    return true;
}

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optional<double>& osgEarth::Features::ResampleFilter::maxLength ( ) [inline]

Definition at line 51 of file ResampleFilter.

{ return _maxLen; }

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const optional<double>& osgEarth::Features::ResampleFilter::maxLength ( ) const [inline]

Definition at line 52 of file ResampleFilter.

{ return _maxLen; }

optional<double>& osgEarth::Features::ResampleFilter::minLength ( ) [inline]

Definition at line 48 of file ResampleFilter.

{ return _minLen; }

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const optional<double>& osgEarth::Features::ResampleFilter::minLength ( ) const [inline]

Definition at line 49 of file ResampleFilter.

{ return _minLen; }

const optional<double>& osgEarth::Features::ResampleFilter::perturbationThreshold ( ) const [inline]

Definition at line 55 of file ResampleFilter.

{ return _perturbThresh; }

optional<double>& osgEarth::Features::ResampleFilter::perturbationThreshold ( ) [inline]

Definition at line 54 of file ResampleFilter.

{ return _perturbThresh; }

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bool ResampleFilter::push	(	Feature *	input,
		FilterContext &	context
	)		`[protected]`

Definition at line 55 of file ResampleFilter.cpp.

{
    if ( !input || !input->getGeometry() )
        return true;

    bool success = true;

    GeometryIterator i( input->getGeometry() );
    while( i.hasMore() )
    {        
        Geometry* part = i.next();

        if ( part->size() < 2 ) continue;

        unsigned int origSize = part->size();

        // copy the original part to a linked list. use a std::list since insert/erase
        // will not invalidate iterators.
        std::list<osg::Vec3d> plist;
        plist.insert( plist.begin(), part->begin(), part->end() );

        std::list<osg::Vec3d>::iterator v1 = plist.begin(); ++v1;
        std::list<osg::Vec3d>::iterator v0 = plist.begin();
        std::list<osg::Vec3d>::iterator last = plist.end(); --last;

        while( v0 != last )
        {
            bool increment = true;

            osg::Vec3d& p0 = *v0;
            osg::Vec3d& p1 = *v1;
            bool lastSeg = v1 == last;
            osg::Vec3d seg = p1 - p0;

            //OE_NOTICE << "p0=" << p0 << " to " << "p1=" << p1 << std::endl;

            osg::Vec3d p0Rad, p1Rad;

            if (_resampleMode.value() == RESAMPLE_GREATCIRCLE || _resampleMode.value() == RESAMPLE_RHUMB)
            {
                p0Rad = osg::Vec3d(osg::DegreesToRadians(p0.x()), osg::DegreesToRadians(p0.y()), p0.z());
                p1Rad = osg::Vec3d(osg::DegreesToRadians(p1.x()), osg::DegreesToRadians(p1.y()), p1.z());
            }
                       
            //Compute the length of the segment
            double segLen = 0.0;
            switch (_resampleMode.value())
            {
            case RESAMPLE_LINEAR:
                segLen = seg.length();
                break;
            case RESAMPLE_GREATCIRCLE:
                segLen = GeoMath::distance(p0Rad.y(), p0Rad.x(), p1Rad.y(), p1Rad.x());
                break;
            case RESAMPLE_RHUMB:
                segLen = GeoMath::rhumbDistance(p0Rad.y(), p0Rad.x(), p1Rad.y(), p1Rad.x());
                break;
            }

            if ( segLen < _minLen.value() && !lastSeg && plist.size() > 2 )
            {
                v1 = plist.erase( v1 );
                increment = false;
            }
            else if ( segLen > _maxLen.value() )
            {
                //Compute the number of divisions to make
                int numDivs = (1 + (int)(segLen/_maxLen.value()));
                double newSegLen = segLen/(double)numDivs;
                seg.normalize();
                osg::Vec3d newPt;
                double newHeight;
                switch (_resampleMode.value())
                {
                case RESAMPLE_LINEAR:
                    {
                        newPt = p0 + seg * newSegLen;
                    }
                    break;
                case RESAMPLE_GREATCIRCLE:
                    {
                        double bearing = GeoMath::bearing(p0Rad.y(), p0Rad.x(), p1Rad.y(), p1Rad.x());
                        double lat,lon;
                        GeoMath::destination(p0Rad.y(), p0Rad.x(), bearing, newSegLen, lat, lon);
                        newHeight = p0Rad.z() + ( p1Rad.z() - p0Rad.z() ) / (double)numDivs;
                        newPt = osg::Vec3d(osg::RadiansToDegrees(lon), osg::RadiansToDegrees(lat), newHeight);
                    }
                    break;
                case RESAMPLE_RHUMB:
                    {
                        double bearing = GeoMath::rhumbBearing(p0Rad.y(), p0Rad.x(), p1Rad.y(), p1Rad.x());
                        double lat,lon;
                        GeoMath::rhumbDestination(p0Rad.y(), p0Rad.x(), bearing, newSegLen, lat, lon);
                        newHeight = p0Rad.z() + ( p1Rad.z() - p0Rad.z() ) / (double)numDivs;
                        newPt = osg::Vec3d(osg::RadiansToDegrees(lon), osg::RadiansToDegrees(lat), newHeight);
                    }
                    break;
                }
                
                if ( _perturbThresh.value() > 0.0 && _perturbThresh.value() < newSegLen )
                {
                    float r = 0.5 - (float)::rand()/(float)RAND_MAX;
                    newPt.x() += r;
                    newPt.y() += r;
                }
                v1 = plist.insert( v1, newPt );
            }

            if ( increment ) { ++v0; ++v1; }
        }

        part->clear();
        part->reserve( plist.size() );
        part->insert( part->begin(), plist.begin(), plist.end() );

        /*
        if ( origSize != part->size() )
        {
            OE_NOTICE << "Resampled part from " << origSize << " to " << part->size() << " points" << std::endl;
        }
        */
    }
    return success;
}

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

Implements osgEarth::Features::FeatureFilter.

Definition at line 182 of file ResampleFilter.cpp.

{
    if ( !isSupported() )
    {
        OE_WARN << "ResampleFilter support not enabled" << std::endl;
        return context;
    }

    bool ok = true;
    for( FeatureList::iterator i = input.begin(); i != input.end(); ++i )
        if ( !push( i->get(), context ) )
            ok = false;

    return context;
}