/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2020 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 OSGEARTHSYMBOLOGY_BILLBOARD_SYMBOL_H
#define OSGEARTHSYMBOLOGY_BILLBOARD_SYMBOL_H 1

#include <climits>

#include <osgEarth/Common>
#include <osgEarth/InstanceSymbol>
#include <osg/Vec3f>

namespace osgEarth
{
    namespace Util {
        class InstanceResource;
    }

    /**
     * Represents a 2D camera-facing image
     */
    class OSGEARTH_EXPORT BillboardSymbol : public InstanceSymbol
    {
    public:
        META_Object(osgEarth, BillboardSymbol);

        BillboardSymbol(const BillboardSymbol& rhs,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);
        BillboardSymbol( const Config& conf =Config() );

        /** dtor */
        virtual ~BillboardSymbol() { }

    public: // properties

        //! URL or the top image
        optional<StringExpression>& topURL() { return _topURL; }
        const optional<StringExpression>& topURL() const { return _topURL; }

        //! Width of the billboard image in meters */
        optional<float>& width() { return _width; }
        const optional<float>& width() const { return _width; }

        //! Height of the billboard image in meters */
        optional<float>& height() { return _height; }
        const optional<float>& height() const { return _height; }

        //! Percentage by which to vary width and height [0..1] default = 0
        optional<float>& sizeVariation() { return _sizeVariation; }
        const optional<float>& sizeVariation() const { return _sizeVariation; }

        //! Weighting of this symbol versus others in the same group.
        //! Should be an integer >= 1. Default = 1.
        optional<unsigned>& selectionWeight() { return _selectionWeight; }
        const optional<unsigned>& selectionWeight() const { return _selectionWeight; }
        
    public: // non-serialized properties (for programmatic use only)

        void setSideImage(osg::Image* value) { _sideImage = value; }
        osg::Image* getSideImage() const { return _sideImage.get(); }

        void setTopImage(osg::Image* value) { _topImage = value; }
        osg::Image* getTopImage() const { return _topImage.get(); }

    public:
        virtual Config getConfig() const;
        virtual void mergeConfig( const Config& conf );
        static void parseSLD(const Config& c, class Style& style);
    
    public: // InstanceSymbol

        /** Creates a new (empty) resource appropriate for this symbol */
        virtual InstanceResource* createResource() const;

    protected:
        optional<StringExpression> _topURL;
        optional<float> _width;
        optional<float> _height;
        optional<float> _sizeVariation;
        optional<unsigned> _selectionWeight;
        osg::ref_ptr<osg::Image> _sideImage;
        osg::ref_ptr<osg::Image> _topImage;
    };
} // namespace osgEarth

#endif