/* osgEarth
* Copyright 2008-2012 Pelican Mapping
* MIT License
*/
#ifndef OSGEARTH_SPLAT_SPLAT_LAYER_H
#define OSGEARTH_SPLAT_SPLAT_LAYER_H

#include "Export"
#include "Zone"
#include <osgEarth/VisibleLayer>
#include <osgEarth/LayerReference>
#include <osgEarth/LandCoverLayer>

namespace osgEarth { namespace Splat
{
    //! Layer that renders geotypical textures on the terrain based on
    //! classification data ("texture splatting").
    class OSGEARTHSPLAT_EXPORT SplatLayer : public VisibleLayer
    {
    public:
        class OSGEARTHSPLAT_EXPORT Options : public VisibleLayer::Options
        {
        public:
            META_LayerOptions(osgEarth, Options, VisibleLayer::Options);
            OE_OPTION(std::string, landCoverLayer);
            OE_OPTION_VECTOR(ZoneOptions, zones);
            virtual Config getConfig() const;
        private:
            void fromConfig(const Config& conf);
        };

    public:
        META_Layer(osgEarthSplat, SplatLayer, Options, VisibleLayer, SplatImage);

        //! Layer containing required coverage data
        void setLandCoverLayer(LandCoverLayer* landCoverLayer);
        LandCoverLayer* getLandCoverLayer() const { return _landCoverLayer.getLayer(); }

        //! Layer containing the land cover dictionary.
        void setLandCoverDictionary(LandCoverDictionary* landCoverDict);
        LandCoverDictionary* getLandCoverDictionary() const { return _landCoverDict.getLayer(); }

        //! Splatting zones
        Zones& getZones() { return _zones; }
        const Zones& getZones() const { return _zones; }

    protected:

        //! Override post-ctor init
        virtual void init() override;
        virtual Status openImplementation() override;
        virtual void prepareForRendering(TerrainEngine*) override;

        //! Serialize
        virtual Config getConfig() const override;

    public:

        //! Called when this layer is added to the map
        virtual void addedToMap(const Map* map) override;
        virtual void removedFromMap(const Map* map) override;

    public:

        virtual void resizeGLObjectBuffers(unsigned maxSize) override;
        virtual void releaseGLObjects(osg::State* state) const override;

    protected:
        virtual ~SplatLayer() { }

        LayerReference<LandCoverDictionary> _landCoverDict;
        LayerReference<LandCoverLayer> _landCoverLayer;

        TextureImageUnitReservation _splatBinding;
        TextureImageUnitReservation _lutBinding;
        TextureImageUnitReservation _noiseBinding;

        Zones _zones;
        bool _zonesConfigured;
        bool _editMode;
        bool _gpuNoise;

        void buildStateSets();

        struct ZoneSelector : public Layer::TraversalCallback
        {
            SplatLayer* _layer;
            ZoneSelector(SplatLayer* layer) : _layer(layer) { }
            void operator()(osg::Node*, osg::NodeVisitor*) const;
        };
        friend struct ZoneSelector;
    };

} } // namespace osgEarth::Splat

#endif // OSGEARTH_SPLAT_SPLAT_LAYER_FACTORY_H
