libosgearth-dev 2.4.0+dfsg-6 / usr / include / osgEarthAnnotation / Decluttering

/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2013 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/
#ifndef OSGEARTH_ANNOTATION_DECLUTTER_RENDER_BIN_H
#define OSGEARTH_ANNOTATION_DECLUTTER_RENDER_BIN_H 1

#include <osgEarthAnnotation/Common>
#include <osgEarth/Config>
#include <osg/Drawable>
#include <osgUtil/RenderLeaf>
#include <limits.h>

/**
 * To apply the "decluttering" algorithm to a subgraph, call
 *
 * Decluttering::setEnabled( node->getOrCreateStateSet(), true );
 */

#define OSGEARTH_DECLUTTER_BIN "declutter"

namespace osgEarth { namespace Annotation 
{
    /**
     * Marker class hinting that an implementation supports the decluttering
     * render bin.
     */
    class SupportsDecluttering
    {
        //nop
    };

    /**
     * Custom functor that compares two RenderLeaf's and returns TRUE if the left-hand one
     * is higher priority, otherwise FALSE. You can call setDeclutterPriorityFunctor()
     * to set a custom priority-sorting functor.
     */
    struct DeclutterSortFunctor : public osg::Referenced
    {
        virtual bool operator() ( const osgUtil::RenderLeaf* lhs, const osgUtil::RenderLeaf* rhs ) const =0;
        virtual ~DeclutterSortFunctor() { }
    };

    /**
     * A decluttering functor that sorts by the priority field in AnnotationData.
     * AnnotationData should be attached to each Drawable's user data.
     */
    struct OSGEARTHANNO_EXPORT DeclutterByPriority : public DeclutterSortFunctor
    {
        virtual bool operator()(const osgUtil::RenderLeaf* lhs, const osgUtil::RenderLeaf* rhs ) const;
        virtual ~DeclutterByPriority() { }
    };

    /**
     * Options to control the annotation decluttering engine.
     */
    class OSGEARTHANNO_EXPORT DeclutteringOptions
    {
    public:
        DeclutteringOptions( const Config& conf =Config() )
            : _minAnimAlpha         ( 0.35f ),
              _minAnimScale         ( 0.45f ),
              _inAnimTime           ( 0.40f ),
              _outAnimTime          ( 0.00f ),
              _sortByPriority       ( false ),
              _maxObjects           ( INT_MAX )
        {
            fromConfig(conf);
        }

        virtual ~DeclutteringOptions() { }

        /** Alpha value of a fully-occluded object */
        optional<float>& minAnimationAlpha() { return _minAnimAlpha; }
        const optional<float>& minAnimationAlpha() const { return _minAnimAlpha; }

        /** Scale factor of a fully-occluded object */
        optional<float>& minAnimationScale() { return _minAnimScale; }
        const optional<float>& minAnimationScale() const { return _minAnimScale; }

        /** Time (in seconds) for an object to transition from occluded to visible */
        optional<float>& inAnimationTime() { return _inAnimTime; }
        const optional<float>& inAnimationTime() const { return _inAnimTime; }

        /** Time (in seconds) for an object to transition from visible to occluded */
        optional<float>& outAnimationTime() { return _outAnimTime; }
        const optional<float>& outAnimationTime() const { return _outAnimTime; }

        /** If set, activate the AnnotationData priority-based sorting */
        optional<bool>& sortByPriority() { return _sortByPriority; }
        const optional<bool>& sortByPriority() const { return _sortByPriority; }

        /** Maximum number of objects to draw after sorting */
        optional<unsigned>& maxObjects() { return _maxObjects; }
        const optional<unsigned>& maxObjects() const { return _maxObjects; }

    public:

        Config getConfig() const;

    protected:
        optional<float>    _minAnimAlpha;
        optional<float>    _minAnimScale;
        optional<float>    _inAnimTime;
        optional<float>    _outAnimTime;
        optional<bool>     _sortByPriority;
        optional<unsigned> _maxObjects;

        void fromConfig( const Config& conf );
    };

    struct OSGEARTHANNO_EXPORT Decluttering
    {
        /**
         * Enables or disables decluttering on a stateset.
         */
        static void setEnabled( osg::StateSet* stateSet, bool enabled, int binNum =INT_MAX );

        /**
         * Enables or disables decluttering globally.
         */
        static void setEnabled( bool enabled );

        /**
         * Sets a functor to use to determine render leaf priority for declutter sorting.
         */
        static void setSortFunctor( DeclutterSortFunctor* f );

        /**
         * Clears a custom priority functor that was set using setDeclutterPriorityFunctor,
         * reverting to the default behavior (which is to sort by distance from the camera).
         */
        static void clearSortFunctor();

        /**
         * Applies the provided options to the decluttering engine.
         */
        static void setOptions( const DeclutteringOptions& options );

        /**
         * Fetches the current decluttering options
         */
        static const DeclutteringOptions& getOptions();
    };

} } // namespace osgEarth::Annotation

#endif //OSGEARTH_ANNOTATION_DECLUTTER_RENDER_BIN_H