/* -*-c++-*- */
/* osgEarth - Geospatial SDK for OpenSceneGraph
 * Copyright 2019 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_ICON_SYMBOL_H
#define OSGEARTHSYMBOLOGY_ICON_SYMBOL_H 1

#include <osgEarth/Common>
#include <osgEarthSymbology/InstanceSymbol>

namespace osgEarth { namespace Symbology
{
    class Style;
    class InstanceResource;

    /**
     * Represents a 2D icon for instancing
     */
    class OSGEARTHSYMBOLOGY_EXPORT IconSymbol : public InstanceSymbol
    {
    public:
        // note: these are similar to the values in osgText::Text::AlignmentType
        enum Alignment {
            ALIGN_LEFT_TOP,
            ALIGN_LEFT_CENTER,
            ALIGN_LEFT_BOTTOM,

            ALIGN_CENTER_TOP,
            ALIGN_CENTER_CENTER,
            ALIGN_CENTER_BOTTOM,

            ALIGN_RIGHT_TOP,
            ALIGN_RIGHT_CENTER,
            ALIGN_RIGHT_BOTTOM,
        };

    public:
        META_Object(osgEarthSymbology, IconSymbol);

        IconSymbol(const IconSymbol& rhs,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY);

        IconSymbol( const Config& conf =Config() );

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

        /** Alignment of the marker relative to center pixels */
        optional<Alignment>& alignment() { return _alignment; }
        const optional<Alignment>& alignment() const { return _alignment; }

        /** Heading. Semantically this differs from an model's heading */
        optional<NumericExpression>& heading() { return _heading; }
        const optional<NumericExpression>& heading() const { return _heading; }

        /** Decluttering */
        optional<bool>& declutter() { return _declutter; }
        const optional<bool>& declutter() const { return _declutter; }

        /** Whether to enable occlusion culling on the icon, if applicable */
        optional<bool>& occlusionCull() { return _occlusionCull; }
        const optional<bool>& occlusionCull() const { return _occlusionCull; }

        /** The camera altitude at which to start occlusion culling the icon */
        optional<double>& occlusionCullAltitude() { return _occlusionCullAltitude; }
        const optional<double>& occlusionCullAltitude() const { return _occlusionCullAltitude; }
        
    public: // non-serialized properties (for programmatic use only)

        /** Explicit image to use for 2D icon placemet */
        void setImage( osg::Image* image ) { _image = image; }
        osg::Image* getImage( unsigned maxSize =INT_MAX ) const;

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

    public: // InstanceSymbol
        virtual InstanceResource* createResource() const;

    protected:
        optional<Alignment>              _alignment;
        optional<NumericExpression>      _heading;
        optional<bool>                   _declutter;
        mutable osg::ref_ptr<osg::Image> _image;
        optional<bool>                   _occlusionCull;
        optional<double>                 _occlusionCullAltitude;
    };

} } // namespace osgEarth::Symbology

#endif