o3de/Code/CryEngine/CryCommon/CryExtension/ICryUnknown.h

/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/
// Original file Copyright Crytek GMBH or its affiliates, used under license.

// Description : Part of CryEngine's extension framework.


#ifndef CRYINCLUDE_CRYEXTENSION_ICRYUNKNOWN_H
#define CRYINCLUDE_CRYEXTENSION_ICRYUNKNOWN_H
#pragma once


#include "CryTypeID.h"
#include <SmartPointersHelpers.h>


struct ICryFactory;
struct ICryUnknown;

namespace InterfaceCastSemantics
{
    template <class T>
    const CryInterfaceID& cryiidof()
    {
        return T::IID();
    }

#define _BEFRIEND_CRYIIDOF() \
    template <class T>       \
    friend const CryInterfaceID&InterfaceCastSemantics::cryiidof();


    template <class Dst, class Src>
    Dst* cryinterface_cast(Src* p)
    {
        return static_cast<Dst*>(p ? p->QueryInterface(cryiidof<Dst>()) : 0);
    }

    template <class Dst, class Src>
    Dst* cryinterface_cast(const Src* p)
    {
        return static_cast<const Dst*>(p ? p->QueryInterface(cryiidof<Dst>()) : 0);
    }

    namespace Internal
    {
        template <class Dst, class Src>
        struct cryinterface_cast_shared_ptr_helper;

        template <class Dst, class Src>
        struct cryinterface_cast_shared_ptr_helper
        {
            static AZStd::shared_ptr<Dst> Op(const AZStd::shared_ptr<Src>& p)
            {
                Dst* dp = cryinterface_cast<Dst>(p.get());
                return dp ? AZStd::shared_ptr<Dst>(p, dp) : AZStd::shared_ptr<Dst>();
            }
        };

        template <class Src>
        struct cryinterface_cast_shared_ptr_helper<ICryUnknown, Src>
        {
            static AZStd::shared_ptr<ICryUnknown> Op(const AZStd::shared_ptr<Src>& p)
            {
                ICryUnknown* dp = cryinterface_cast<ICryUnknown>(p.get());
                return dp ? AZStd::shared_ptr<ICryUnknown>(*((const AZStd::shared_ptr<ICryUnknown>*) & p), dp) : AZStd::shared_ptr<ICryUnknown>();
            }
        };

        template <class Src>
        struct cryinterface_cast_shared_ptr_helper<const ICryUnknown, Src>
        {
            static AZStd::shared_ptr<const ICryUnknown> Op(const AZStd::shared_ptr<Src>& p)
            {
                const ICryUnknown* dp = cryinterface_cast<const ICryUnknown>(p.get());
                return dp ? AZStd::shared_ptr<const ICryUnknown>(*((const AZStd::shared_ptr<const ICryUnknown>*) & p), dp) : AZStd::shared_ptr<const ICryUnknown>();
            }
        };
    } // namespace Internal

    template <class Dst, class Src>
    AZStd::shared_ptr<Dst> cryinterface_cast(const AZStd::shared_ptr<Src>& p)
    {
        return Internal::cryinterface_cast_shared_ptr_helper<Dst, Src>::Op(p);
    }

#define _BEFRIEND_CRYINTERFACE_CAST()                                   \
    template <class Dst, class Src>                                     \
    friend Dst * InterfaceCastSemantics::cryinterface_cast(Src*);       \
    template <class Dst, class Src>                                     \
    friend Dst * InterfaceCastSemantics::cryinterface_cast(const Src*); \
    template <class Dst, class Src>                                     \
    friend AZStd::shared_ptr<Dst> InterfaceCastSemantics::cryinterface_cast(const AZStd::shared_ptr<Src>&);
} // namespace InterfaceCastSemantics

using InterfaceCastSemantics::cryiidof;
using InterfaceCastSemantics::cryinterface_cast;


template <class S, class T>
bool CryIsSameClassInstance(S* p0, T* p1)
{
    return static_cast<const void*>(p0) == static_cast<const void*>(p1) || cryinterface_cast<const ICryUnknown>(p0) == cryinterface_cast<const ICryUnknown>(p1);
}

template <class S, class T>
bool CryIsSameClassInstance(const AZStd::shared_ptr<S>& p0, T* p1)
{
    return CryIsSameClassInstance(p0.get(), p1);
}

template <class S, class T>
bool CryIsSameClassInstance(S* p0, const AZStd::shared_ptr<T>& p1)
{
    return CryIsSameClassInstance(p0, p1.get());
}

template <class S, class T>
bool CryIsSameClassInstance(const AZStd::shared_ptr<S>& p0, const AZStd::shared_ptr<T>& p1)
{
    return CryIsSameClassInstance(p0.get(), p1.get());
}


namespace CompositeQuerySemantics
{
    template <class Src>
    AZStd::shared_ptr<ICryUnknown> crycomposite_query(Src* p, const char* name, bool* pExposed = 0)
    {
        void* pComposite = p ? p->QueryComposite(name) : 0;
        pExposed ? *pExposed = pComposite != 0 : 0;
        return pComposite ? *static_cast<AZStd::shared_ptr<ICryUnknown>*>(pComposite) : AZStd::shared_ptr<ICryUnknown>();
    }

    template <class Src>
    AZStd::shared_ptr<const ICryUnknown> crycomposite_query(const Src* p, const char* name, bool* pExposed = 0)
    {
        void* pComposite = p ? p->QueryComposite(name) : 0;
        pExposed ? *pExposed = pComposite != 0 : 0;
        return pComposite ? *static_cast<AZStd::shared_ptr<const ICryUnknown>*>(pComposite) : AZStd::shared_ptr<const ICryUnknown>();
    }

    template <class Src>
    AZStd::shared_ptr<ICryUnknown> crycomposite_query(const AZStd::shared_ptr<Src>& p, const char* name, bool* pExposed = 0)
    {
        return crycomposite_query(p.get(), name, pExposed);
    }

    template <class Src>
    AZStd::shared_ptr<const ICryUnknown> crycomposite_query(const AZStd::shared_ptr<const Src>& p, const char* name, bool* pExposed = 0)
    {
        return crycomposite_query(p.get(), name, pExposed);
    }

#define _BEFRIEND_CRYCOMPOSITE_QUERY()                                                                                                    \
    template <class Src>                                                                                                                  \
    friend AZStd::shared_ptr<ICryUnknown> CompositeQuerySemantics::crycomposite_query(Src*, const char*, bool*);                          \
    template <class Src>                                                                                                                  \
    friend AZStd::shared_ptr<const ICryUnknown> CompositeQuerySemantics::crycomposite_query(const Src*, const char*, bool*);              \
    template <class Src>                                                                                                                  \
    friend AZStd::shared_ptr<ICryUnknown> CompositeQuerySemantics::crycomposite_query(const AZStd::shared_ptr<Src>&, const char*, bool*); \
    template <class Src>                                                                                                                  \
    friend AZStd::shared_ptr<const ICryUnknown> CompositeQuerySemantics::crycomposite_query(const AZStd::shared_ptr<const Src>&, const char*, bool*);
} // namespace CompositeQuerySemantics

using CompositeQuerySemantics::crycomposite_query;


#define _BEFRIEND_MAKE_SHARED() \
    template <class T>                                      \
    friend class AZStd::Internal::sp_ms_deleter;            \
    template <class T>                                      \
    friend AZStd::shared_ptr<T> AZStd::make_shared();       \
    template <class T, class A>                             \
    friend AZStd::shared_ptr<T> AZStd::allocate_shared(A const& a);

// prevent explicit destruction from client side
#define _PROTECTED_DTOR(iname) \
protected:                     \
    virtual ~iname() {}


// Befriending cryinterface_cast<T>() and crycomposite_query() via CRYINTERFACE_DECLARE is actually only needed for ICryUnknown
// since QueryInterface() and QueryComposite() are usually not redeclared in derived interfaces but it doesn't hurt either
#define CRYINTERFACE_DECLARE(iname, iidHigh, iidLow)                                   \
    _BEFRIEND_CRYIIDOF()                                                               \
    _BEFRIEND_CRYINTERFACE_CAST()                                                      \
    _BEFRIEND_CRYCOMPOSITE_QUERY()                                                     \
    _BEFRIEND_MAKE_SHARED()                                                            \
    _PROTECTED_DTOR(iname)                                                             \
                                                                                       \
private:                                                                               \
    static const CryInterfaceID& IID()                                                 \
    {                                                                                  \
        static const CryInterfaceID iid = {(uint64) iidHigh##LL, (uint64) iidLow##LL}; \
        return iid;                                                                    \
    }                                                                                  \
public:


struct ICryUnknown
{
    CRYINTERFACE_DECLARE(ICryUnknown, 0x1000000010001000, 0x1000100000000000)

    virtual ICryFactory * GetFactory() const = 0;

protected:
    virtual void* QueryInterface(const CryInterfaceID& iid) const = 0;
    virtual void* QueryComposite(const char* name) const = 0;
};

DECLARE_SMART_POINTERS(ICryUnknown);


#endif // CRYINCLUDE_CRYEXTENSION_ICRYUNKNOWN_H