/** Calculates a pose for a given time of an animation */
/*
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Open Asset Import Library (ASSIMP)
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Copyright (c) 2006-2008, ASSIMP Development Team

All rights reserved.

Redistribution and use of this software in source and binary forms, 
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* Redistributions of source code must retain the above
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  following disclaimer.

* Redistributions in binary form must reproduce the above
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  written permission of the ASSIMP Development Team.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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*/

#ifndef AV_ANIMEVALUATOR_H_INCLUDED
#define AV_ANIMEVALUATOR_H_INCLUDED

#include <boost/tuple/tuple.hpp>

namespace AssimpView
{

class AnimEvaluator
{
public:
	/** Constructor on a given animation. The animation is fixed throughout the lifetime of
	 * the object.
	 * @param pAnim The animation to calculate poses for. Ownership of the animation object stays
	 *   at the caller, the evaluator just keeps a reference to it as long as it persists.
	 */
	AnimEvaluator( const aiAnimation* pAnim);

	/** Evaluates the animation tracks for a given time stamp. The calculated pose can be retrieved as a
	 * array of transformation matrices afterwards by calling GetTransformations().
	 * @param pTime The time for which you want to evaluate the animation, in seconds. Will be mapped into the animation cycle, so
	 *   it can be an arbitrary value. Best use with ever-increasing time stamps.
	 */
	void Evaluate( double pTime);

	/** Returns the transform matrices calculated at the last Evaluate() call. The array matches the mChannels array of
	 * the aiAnimation. */
	const std::vector<aiMatrix4x4>& GetTransformations() const { return mTransforms; }

protected:
	/** The animation we're working on */
	const aiAnimation* mAnim;

	/** At which frame the last evaluation happened for each channel. 
	 * Useful to quickly find the corresponding frame for slightly increased time stamps
	 */
	double mLastTime;
	std::vector<boost::tuple<unsigned int, unsigned int, unsigned int> > mLastPositions;

	/** The array to store the transformations results of the evaluation */
	std::vector<aiMatrix4x4> mTransforms;
};

} // end of namespace AssimpView

#endif // AV_ANIMEVALUATOR_H_INCLUDED