/***************************************************************************
 * Copyright 1998-2015 by authors (see AUTHORS.txt)                        *
 *                                                                         *
 *   This file is part of LuxRender.                                       *
 *                                                                         *
 * Licensed under the Apache License, Version 2.0 (the "License");         *
 * you may not use this file except in compliance with the License.        *
 * You may obtain a copy of the License at                                 *
 *                                                                         *
 *     http://www.apache.org/licenses/LICENSE-2.0                          *
 *                                                                         *
 * Unless required by applicable law or agreed to in writing, software     *
 * distributed under the License is distributed on an "AS IS" BASIS,       *
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.*
 * See the License for the specific language governing permissions and     *
 * limitations under the License.                                          *
 ***************************************************************************/

#ifndef _SLG_CLEARVOL_H
#define	_SLG_CLEARVOL_H

#include "slg/volumes/volume.h"

namespace slg {

//------------------------------------------------------------------------------
// ClearVolume
//------------------------------------------------------------------------------

class ClearVolume : public Volume {
public:
	ClearVolume(const Texture *iorTex, const Texture *emiTex, const Texture *a);

	virtual float Scatter(const luxrays::Ray &ray, const float u, const bool scatteredStart,
		luxrays::Spectrum *connectionThroughput, luxrays::Spectrum *connectionEmission) const;

	// Material interface

	virtual MaterialType GetType() const { return CLEAR_VOL; }
	virtual BSDFEvent GetEventTypes() const { return DIFFUSE | REFLECT; };

	virtual luxrays::Spectrum Evaluate(const HitPoint &hitPoint,
		const luxrays::Vector &localLightDir, const luxrays::Vector &localEyeDir, BSDFEvent *event,
		float *directPdfW = NULL, float *reversePdfW = NULL) const;
	virtual luxrays::Spectrum Sample(const HitPoint &hitPoint,
		const luxrays::Vector &localFixedDir, luxrays::Vector *localSampledDir,
		const float u0, const float u1, const float passThroughEvent,
		float *pdfW, float *absCosSampledDir, BSDFEvent *event,
		const BSDFEvent requestedEvent) const;
	virtual void Pdf(const HitPoint &hitPoint,
		const luxrays::Vector &localLightDir, const luxrays::Vector &localEyeDir,
		float *directPdfW, float *reversePdfW) const;

	virtual void AddReferencedTextures(boost::unordered_set<const Texture *> &referencedTexs) const;
	virtual void UpdateTextureReferences(const Texture *oldTex, const Texture *newTex);

	virtual luxrays::Properties ToProperties() const;

	const Texture *GetSigmaA() const { return sigmaA; }

protected:
	virtual luxrays::Spectrum SigmaA(const HitPoint &hitPoint) const;
	virtual luxrays::Spectrum SigmaS(const HitPoint &hitPoint) const;

private:
	const Texture *sigmaA;
};

}

#endif	/* _SLG_CLEARVOL_H */
