/* -*-c++-*- */
/* osgEarth - Geospatial SDK 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 <osgEarth/VisibleLayer>
#include <osgEarth/Color>
#include <osg/Texture1D>
#include <osg/Texture2D>
#include <osg/TransferFunction>

namespace osgEarth
{
    /**
     * Layer that renders a color ramp based on Elevation data in the Map.
     */
    class OSGEARTH_EXPORT ContourMapLayer : public VisibleLayer
    {
    public:
        class OSGEARTH_EXPORT Options : public VisibleLayer::Options {
        public:
            META_LayerOptions(osgEarth, Options, VisibleLayer::Options);
            struct Stop {
                float elevation;
                Color color;
            };
            OE_OPTION_VECTOR(Stop, stops);
            virtual Config getConfig() const;
            static Config getMetadata();
        private:
            void fromConfig(const Config& conf);
        };

    public:
        META_Layer(osgEarth, ContourMapLayer, Options, VisibleLayer, ContourMap);

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

    public: // Layer

        //! Called by constructors
        virtual void init() override;

        //! MapNode will call this function when terrain resources are available
        virtual void prepareForRendering(TerrainEngine*) override;

        //! Release resources on close
        virtual Status closeImplementation() override;

    protected:

        //! Destructor
        virtual ~ContourMapLayer() { }

#if defined(OSG_GLES2_AVAILABLE) || defined(OSG_GLES3_AVAILABLE)
        typedef osg::Texture2D TextureType;
#else
        typedef osg::Texture1D TextureType;
#endif

        TextureImageUnitReservation           _reservation;
        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;
    };

}
OSGEARTH_SPECIALIZE_CONFIG(osgEarth::ContourMapLayer::Options);


#endif // OSGEARTHUTIL_CONTOUR_MAP_H