assimp/code/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 <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
    {
        explicit 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
    {
        explicit 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