#ifndef POTENTIAL_H
#define POTENTIAL_H

/**
 * @author  Fabrizio Morciano <fabrizio.morciano@gmail.com>
 */

#include "tcommon.h"

#undef DVAPI
#undef DVVAR
#ifdef TNZEXT_EXPORTS
#define DVAPI DV_EXPORT_API
#define DVVAR DV_EXPORT_VAR
#else
#define DVAPI DV_IMPORT_API
#define DVVAR DV_IMPORT_VAR
#endif

#include <assert.h>
#include <stdexcept>
#include <string>

class TStroke;

#if defined(_WIN32) && (_MSC_VER <= 1200)
// to avoid annoying warning
#pragma warning(push)
#pragma warning(disable : 4290)
#endif

namespace ToonzExt
{
/**
  * @brief Potential is an abstraction to maintain a 
  * mathematical potential function. 
  *
  * It is used from StrokeDeformation to change 
  * the behaviour of deformation that user need to do.
  */
class DVAPI
	Potential
{
	bool isValid_;

protected:
	/**
     * @brief The value of potential at parameter w on
     *  the stroke.
     * @param w The parameter on stroke.
     */
	virtual double
	value_(double w) const = 0;

	/**
     * @brief Change the parameter of object that has been created.
     *
     * This method is the real implementation that a potential
     * needs to implement.
     * @param theStroke The stroke to change.
     * @param w The parameter on stroke.
     * @param actionLength How many stroke to change.
     */
	virtual void
	setParameters_(const TStroke *theStroke,
				   double w,
				   double actionLength) = 0;

public:
	Potential();

	/**
     * @brief Just a wrapper for setParameters_.
     * @sa setParameters_
     */
	void
	setParameters(const TStroke *ref,
				  double w,
				  double actionLength);

	/**
     * @brief Just a wrapper for value_.
     * @sa value_
     */
	double
	value(double at) const;

	/**
     * @brief This is method required to use a Prototype Pattern.
     */
	virtual Potential *clone() = 0;

	virtual ~Potential() {}
};
}

#if defined(_WIN32) && (_MSC_VER <= 1200)
#pragma warning(pop)
#endif

#endif /* POTENTIAL_H */
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//  End Of File
//-----------------------------------------------------------------------------