BaseProcess.h

/*
Open Asset Import Library (assimp)
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*/

/** @file Base class of all import post processing steps */
#ifndef INCLUDED_AI_BASEPROCESS_H
#define INCLUDED_AI_BASEPROCESS_H

#include <map>

#include "../include/assimp/types.h"
#include "GenericProperty.h"

struct aiScene;

namespace Assimp	{

class Importer;

// ---------------------------------------------------------------------------
/** Helper class to allow post-processing steps to interact with each other.
 *
 *  The class maintains a simple property list that can be used by pp-steps
 *  to provide additional information to other steps. This is primarily
 *  intended for cross-step optimizations.
 */
class SharedPostProcessInfo
{
public:

	struct Base
	{
		virtual ~Base()
		{}
	};

	//! Represents data that is allocated on the heap, thus needs to be deleted
	template <typename T>
	struct THeapData : public Base
	{
		THeapData(T* in)
			: data (in)
		{}

		~THeapData()
		{
			delete data;
		}
		T* data;
	};

	//! Represents static, by-value data not allocated on the heap
	template <typename T>
	struct TStaticData : public Base
	{
		TStaticData(T in)
			: data (in)
		{}

		~TStaticData()
		{}

		T data;
	};

	// some typedefs for cleaner code
	typedef unsigned int KeyType;
	typedef std::map<KeyType, Base*>  PropertyMap;

public:

	//! Destructor
	~SharedPostProcessInfo()	
	{
		Clean();
	}

	//! Remove all stored properties from the table
	void Clean()
	{
		// invoke the virtual destructor for all stored properties
		for (PropertyMap::iterator it = pmap.begin(), end = pmap.end();
			 it != end; ++it)
		{
			delete (*it).second;
		}
		pmap.clear();
	}

	//! Add a heap property to the list
	template <typename T>
	void AddProperty( const char* name, T* in ){
		AddProperty(name,(Base*)new THeapData<T>(in));
	}

	//! Add a static by-value property to the list
	template <typename T>
	void AddProperty( const char* name, T in ){
		AddProperty(name,(Base*)new TStaticData<T>(in));
	}


	//! Get a heap property
	template <typename T>
	bool GetProperty( const char* name, T*& out ) const
	{
		THeapData<T>* t = (THeapData<T>*)GetPropertyInternal(name);
		if(!t)
		{
			out = NULL;
			return false;
		}
		out = t->data;
		return true;
	}

	//! Get a static, by-value property
	template <typename T>
	bool GetProperty( const char* name, T& out ) const
	{
		TStaticData<T>* t = (TStaticData<T>*)GetPropertyInternal(name);
		if(!t)return false;
		out = t->data;
		return true;
	}

	//! Remove a property of a specific type
	void RemoveProperty( const char* name)	{
		SetGenericPropertyPtr<Base>(pmap,name,NULL);
	}

private:

	void AddProperty( const char* name, Base* data)	{
		SetGenericPropertyPtr<Base>(pmap,name,data);
	}

	Base* GetPropertyInternal( const char* name) const	{
		return GetGenericProperty<Base*>(pmap,name,NULL);
	}

private:

	//! Map of all stored properties
	PropertyMap pmap;
};

#if 0

// ---------------------------------------------------------------------------
/** @brief Represents a dependency table for a postprocessing steps.
 *
 *  For future use.
 */
 struct PPDependencyTable 
 {
	 unsigned int execute_me_before_these;
	 unsigned int execute_me_after_these;
	 unsigned int only_if_these_are_not_specified;
	 unsigned int mutually_exclusive_with;
 };

#endif


#define AI_SPP_SPATIAL_SORT "$Spat"

// ---------------------------------------------------------------------------
/** The BaseProcess defines a common interface for all post processing steps.
 * A post processing step is run after a successful import if the caller
 * specified the corresponding flag when calling ReadFile(). 
 * Enum #aiPostProcessSteps defines which flags are available. 
 * After a successful import the Importer iterates over its internal array 
 * of processes and calls IsActive() on each process to evaluate if the step 
 * should be executed. If the function returns true, the class' Execute() 
 * function is called subsequently.
 */
class ASSIMP_API_WINONLY BaseProcess 
{
	friend class Importer;

public:

	/** Constructor to be privately used by Importer */
	BaseProcess();

	/** Destructor, private as well */
	virtual ~BaseProcess();

public:

	// -------------------------------------------------------------------
	/** Returns whether the processing step is present in the given flag.
	 * @param pFlags The processing flags the importer was called with. A
	 *   bitwise combination of #aiPostProcessSteps.
	 * @return true if the process is present in this flag fields, 
	 *   false if not.
	*/
	virtual bool IsActive( unsigned int pFlags) const = 0;

	// -------------------------------------------------------------------
	/** Check whether this step expects its input vertex data to be 
	 *  in verbose format. */
	virtual bool RequireVerboseFormat() const;

	// -------------------------------------------------------------------
	/** Executes the post processing step on the given imported data.
	* The function deletes the scene if the postprocess step fails (
	* the object pointer will be set to NULL).
	* @param pImp Importer instance (pImp->mScene must be valid)
	*/
	void ExecuteOnScene( Importer* pImp);

	// -------------------------------------------------------------------
	/** Called prior to ExecuteOnScene().
	* The function is a request to the process to update its configuration
	* basing on the Importer's configuration property list.
	*/
	virtual void SetupProperties(const Importer* pImp);

	// -------------------------------------------------------------------
	/** Executes the post processing step on the given imported data.
	* A process should throw an ImportErrorException* if it fails.
	* This method must be implemented by deriving classes.
	* @param pScene The imported data to work at.
	*/
	virtual void Execute( aiScene* pScene) = 0;


	// -------------------------------------------------------------------
	/** Assign a new SharedPostProcessInfo to the step. This object
	 *  allows multiple postprocess steps to share data.
	 * @param sh May be NULL
	*/
	inline void SetSharedData(SharedPostProcessInfo* sh)	{
		shared = sh;
	}

	// -------------------------------------------------------------------
	/** Get the shared data that is assigned to the step.
	*/
	inline SharedPostProcessInfo* GetSharedData()	{
		return shared;
	}

protected:

	/** See the doc of #SharedPostProcessInfo for more details */
	SharedPostProcessInfo* shared;

	/** Currently active progress handler */
	ProgressHandler* progress;
};


} // end of namespace Assimp

#endif // AI_BASEPROCESS_H_INC