#pragma once
#include "RenderTechnique.h"

/**
	@brief Base abstract class of rendering a particle system with the spherical billboard method. 	
*/
class HierarchicalParticleSystemTechnique : virtual public RenderTechnique
{
public:
	/**
		@brief Constructor.

		@param parentRenderable the object to operate on
		@param parentTechniqueGroup the TechniqueGroup this RenderedTechnique is attached to
	*/
	HierarchicalParticleSystemTechnique(
							unsigned long startFrame,
							unsigned long impostorUpdateInterval,
							unsigned int impostorResolution,
							bool useDistCalc,
							bool perspectiveRendering,
							ElementaryRenderable* parentRenderable,
							TechniqueGroup* parentTechniqueGroup
							);
	~HierarchicalParticleSystemTechnique();

	void update(unsigned long frameNum);

protected:
	unsigned long impostorUpdateInterval;
	unsigned int impostorResolution;
	/**
			@brief offset in frame number used during update
	*/
	unsigned long startFrame;	
	bool useDistCalc;
	bool perspectiveRendering;

	virtual RenderingRun* createChildPSysRenderingRun()=0;
	
};