/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2012 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.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* 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 OSGEARTHUTIL_CONTOUR_MAP_H
#define OSGEARTHUTIL_CONTOUR_MAP_H

#include <osgEarthUtil/Common>
#include <osgEarth/TerrainEffect>
#include <osgEarth/ImageLayer>
#include <osgEarth/Extension>
#include <osg/Texture1D>
#include <osg/Texture2D>
#include <osg/TransferFunction>

namespace osgEarth {
    class Map;
    class MapNode;
}

namespace osgEarth { namespace Util
{
    class OSGEARTHUTIL_EXPORT ContourMapOptions : public ConfigOptions
    {
    public:
        ContourMapOptions(const ConfigOptions& conf =ConfigOptions()) : ConfigOptions(conf),
            _opacity(1.0f), _grayscale(false)
        {
            fromConfig(_conf);
        }
    public:
        optional<float>& opacity() { return _opacity; }
        const optional<float>& opacity() const { return _opacity; }

        optional<bool>& grayscale() { return _grayscale; }
        const optional<bool>& grayscale() const { return _grayscale; }

    public:
        void fromConfig(const Config& conf) {
            conf.getIfSet("opacity", _opacity);
            conf.getIfSet("grayscale", _grayscale);
        }
        Config getConfig() const {
            Config conf;
            conf.addIfSet("opacity", _opacity);
            conf.addIfSet("grayscale", _grayscale);
            return conf;
        }
        
    private:
        optional<float> _opacity;
        optional<bool>  _grayscale;
    };

    /**
     * Terrain effect that applies a 1D contour coloring texture
     * to the terrain based an on elevation->color map.
     */
    class OSGEARTHUTIL_EXPORT ContourMap : public TerrainEffect,
                                           public ContourMapOptions
    {
    public:
#if defined(OSG_GLES2_AVAILABLE) || defined(OSG_GLES3_AVAILABLE)
        typedef osg::Texture2D TextureType;
#else
        typedef osg::Texture1D TextureType;
#endif
    
        /** construct a new effect */
        ContourMap();
        ContourMap(const ConfigOptions& co);

        /** Sets a custom transfer function. */
        void setTransferFunction(osg::TransferFunction1D* xf);
        osg::TransferFunction1D* getTransferFunction() const { return _xfer.get(); }

        /** rebuild after changing one of the options */
        void dirty();

    public: // TerrainEffect interface

        void onInstall(TerrainEngineNode* engine);
        void onUninstall(TerrainEngineNode* engine);

    protected:
        virtual ~ContourMap();
        void init();

        int                                   _unit;
        osg::ref_ptr<osg::TransferFunction1D> _xfer;
        osg::ref_ptr<TextureType>             _xferTexture;
        osg::ref_ptr<osg::Uniform>            _xferSampler;
        osg::ref_ptr<osg::Uniform>            _xferMin;
        osg::ref_ptr<osg::Uniform>            _xferRange;
        osg::ref_ptr<osg::Uniform>            _opacityUniform;
    };

    /** Activates contour map from the earth file. */
    class OSGEARTHUTIL_EXPORT ContourMapExtension : public Extension,
                                                    public ExtensionInterface<MapNode>,
                                                    public ContourMapOptions
    {
    public:
        META_Object(osgEarthUtil, ContourMapExtension);

        ContourMapExtension() { }
        ContourMapExtension(const ConfigOptions& co) : ContourMapOptions(co) { }

    public: // ExtensionInterface<MapNode>
        bool connect(MapNode*);
        bool disconnect(MapNode*);

    public: // Extension
        
        // for serialization
        virtual const ConfigOptions& getConfigOptions() const { return *this; }

    protected:
        ContourMapExtension(const ContourMapExtension& rhs, const osg::CopyOp& op) { } // unused
        virtual ~ContourMapExtension() { }

        osg::ref_ptr<ContourMap> _effect;
    };


} } // namespace osgEarth::Util

#endif // OSGEARTHUTIL_CONTOUR_MAP_H
