#pragma once

#include "geomorph.h"
#include "gwutil.h"
#include "gmregistry.h"
#include "gwtypes.h"

namespace geoworld
{
	class WindErosionGM : public HeightMapGeoMorph
	{
	private:
		typedef float RationalType;

		unsigned int _iterations;
		RationalType _frDecayLevel;
		bool _bSmoothPost;

		const IGeoWorldAccessor * _pAccessor;
		const GMScalarField * _psfDensity;

		RationalType _fgaussblur[5][5];

		using NoiseGen = NoiseGenerator< RationalType >;
		NoiseGen _ngen;

		template< typename T >
		inline void grad5( const mars::ScalarField< T > & hmf, const signed int x, const signed int y, VectorTag< RationalType >:: V2 & v ) const
		{
			v.x = (hmf(x + 2, y) - hmf(x - 2, y)) / static_cast< T > (4);
			v.y = (hmf(x, y + 2) - hmf(x, y - 2)) / static_cast< T > (4);
		}

		inline RationalType & gaussblur (const signed int x, const signed int y)
		{
			assert(x >= -2 && y >= -2 && x <= +2 && y <= +2);
			return _fgaussblur[x + 2][y + 2];
		}
		inline RationalType gaussblur (const signed int x, const signed int y) const
		{
			assert(x >= -2 && y >= -2 && x <= +2 && y <= +2);
			return _fgaussblur[x + 2][y + 2];
		}

	public:
		WindErosionGM (
			const unsigned int nIterations = 8,
			const float frDecayLevel = 0.1f,
			const bool bSmoothPost = true
		);
		~WindErosionGM();

		void init (SynthesisSession & manager, const IGeoWorldAccessor & accessor, const unsigned short nMaxWidth, const unsigned short nMaxHeight);
		void doMorph (LockedGWSection & section) const;
	};

	class WindErosionGTFactory : public GeoTemplateFactory, public IOpenGeoMorphFactory
	{
	private:
		mars::RangeX< unsigned int > _mmnIterations;
		float _frDecayLevel;
		bool _bSmoothPost;

	public:
		virtual GeoMorph * createRandomInstance() const;
		virtual void configure( IConfigGTFactory * pFactoryConfig, const IConfigGTFactory::Settings & settings );
	};
}