assimp/include/assimp/ProgressHandler.hpp

/*
Open Asset Import Library (assimp)
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*/

/** @file ProgressHandler.hpp
 *  @brief Abstract base class 'ProgressHandler'.
 */
#ifndef INCLUDED_AI_PROGRESSHANDLER_H
#define INCLUDED_AI_PROGRESSHANDLER_H
#include "types.h"
namespace Assimp	{

// ------------------------------------------------------------------------------------
/** @brief CPP-API: Abstract interface for custom progress report receivers.
 *
 *  Each #Importer instance maintains its own #ProgressHandler. The default 
 *  implementation provided by Assimp doesn't do anything at all. */
class ASSIMP_API ProgressHandler
#ifndef SWIG
	: public Intern::AllocateFromAssimpHeap
#endif
{
protected:
	/** @brief	Default constructor	*/
	ProgressHandler () {
	}
public:
	/** @brief	Virtual destructor	*/
	virtual ~ProgressHandler () {
	}

	// -------------------------------------------------------------------
	/** @brief Progress callback.
	 *  @param percentage An estimate of the current loading progress,
	 *    in percent. Or -1.f if such an estimate is not available.
	 *
	 *  There are restriction on what you may do from within your 
	 *  implementation of this method: no exceptions may be thrown and no
	 *  non-const #Importer methods may be called. It is 
	 *  not generally possible to predict the number of callbacks 
	 *  fired during a single import.
	 *
	 *  @return Return false to abort loading at the next possible
	 *   occasion (loaders and Assimp are generally allowed to perform
	 *   all needed cleanup tasks prior to returning control to the
	 *   caller). If the loading is aborted, #Importer::ReadFile()
	 *   returns always NULL.
	 *   */
	virtual bool Update(float percentage = -1.f) = 0;

	// -------------------------------------------------------------------
	/** @brief Progress callback for file loading steps
	 *  @param numberOfSteps The number of total post-processing
	 *   steps
	 *  @param currentStep The index of the current post-processing
	 *   step that will run, or equal to numberOfSteps if all of
	 *   them has finished. This number is always strictly monotone
	 *   increasing, although not necessarily linearly.
	 *
	 *  @note This is currently only used at the start and the end
	 *   of the file parsing.
	 *   */
	virtual void UpdateFileRead(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
		float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
		Update( f * 0.5f );
	}

	// -------------------------------------------------------------------
	/** @brief Progress callback for post-processing steps
	 *  @param numberOfSteps The number of total post-processing
	 *   steps
	 *  @param currentStep The index of the current post-processing
	 *   step that will run, or equal to numberOfSteps if all of
	 *   them has finished. This number is always strictly monotone
	 *   increasing, although not necessarily linearly.
	 *   */
	virtual void UpdatePostProcess(int currentStep /*= 0*/, int numberOfSteps /*= 0*/) {
		float f = numberOfSteps ? currentStep / (float)numberOfSteps : 1.0f;
		Update( f * 0.5f + 0.5f );
	}

}; // !class ProgressHandler 
// ------------------------------------------------------------------------------------
} // Namespace Assimp

#endif