/*
* 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.

#ifndef CRYINCLUDE_CRYENGINE_RENDERDLL_COMMON_TEXTURES_TEXTURESTREAMPOOL_H
#define CRYINCLUDE_CRYENGINE_RENDERDLL_COMMON_TEXTURES_TEXTURESTREAMPOOL_H
#pragma once


#define TEXSTRM_USE_FREEPOOL

struct STexPool;

struct STexPoolItemHdr
{
    static CryCriticalSection s_sSyncLock;

    STexPoolItemHdr* m_Next;
    STexPoolItemHdr* m_Prev;
    STexPoolItemHdr* m_NextFree;
    STexPoolItemHdr* m_PrevFree;

    STexPoolItemHdr()
        : m_Next(NULL)
        , m_Prev(NULL)
        , m_NextFree(NULL)
        , m_PrevFree(NULL)
    {
    }

    _inline void Unlink();
    _inline void Link(STexPoolItemHdr* Before);
    _inline void UnlinkFree();
    _inline void LinkFree(STexPoolItemHdr* Before);
};

struct STexPoolItem
    : STexPoolItemHdr
{
    STexPool* const m_pOwner;
    CTexture* m_pTex;
    CDeviceTexture* const m_pDevTexture;
    size_t const m_nDeviceTexSize;

    uint32 m_nFreeTick;
    uint8 m_nActiveLod;

    STexPoolItem (STexPool* pOwner, CDeviceTexture* pDevTexture, size_t devSize);
    ~STexPoolItem();

    bool IsFree() const { return m_NextFree != NULL; }

    int GetSize()
    {
        int nSize = sizeof(*this);
        return nSize;
    }
    void GetMemoryUsage(ICrySizer* pSizer) const
    {
        pSizer->AddObject(this, sizeof(*this));
        pSizer->AddObject(m_pDevTexture);
    }
    bool IsStillUsedByGPU(uint32 nCurTick);
};

struct STexPool
{
    uint16 m_Width;
    uint16 m_Height;
    uint16 m_nArraySize;
    D3DFormat m_eFormat;
    size_t m_Size;
    STexPoolItemHdr m_ItemsList;
    ETEX_Type m_eTT;
    uint8 m_nMips;

    int m_nItems;
    int m_nItemsFree;

    ~STexPool();

    size_t GetSize()
    {
        size_t nSize = sizeof(*this);
        STexPoolItemHdr* pIT = m_ItemsList.m_Next;
        while (pIT != &m_ItemsList)
        {
            nSize += static_cast<STexPoolItem*>(pIT)->GetSize();
            pIT = pIT->m_Next;
        }

        return nSize;
    }

    uint32 GetNumSlices() const
    {
        uint32 b = (m_eTT == eTT_Cube) ? 6 : 1;
        return b * m_nArraySize;
    }

    void GetMemoryUsage(ICrySizer* pSizer) const
    {
        pSizer->AddObject(this, sizeof(*this));
        STexPoolItemHdr* pIT = m_ItemsList.m_Next;
        while (pIT != &m_ItemsList)
        {
            pSizer->AddObject(static_cast<STexPoolItem*>(pIT));
            pIT = pIT->m_Next;
        }
    }
};

class CTextureStreamPoolMgr
{
public:
    struct SFrameStats
    {
        SFrameStats()
        {
            memset(this, 0, sizeof(*this));
        }

        int nSoftCreates;
        int nSoftFrees;
        int nHardCreates;
        int nHardFrees;
    };

    struct SPoolStats
    {
        int nWidth;
        int nHeight;
        int nMips;
        uint32 nFormat;
        ETEX_Type eTT;

        int nInUse;
        int nFree;

        int nHardCreatesPerFrame;
        int nSoftCreatesPerFrame;
    };

public:
    CTextureStreamPoolMgr();
    ~CTextureStreamPoolMgr();

    void Flush();

    // Fetch and reset last frame stats
#if !defined(_RELEASE)
    void EnableStatsComputation(bool bCompute) { m_bComputeStats = bCompute; }
    SFrameStats FetchFrameStats()
    {
        SFrameStats frameStats = m_frameStats;
        m_frameStats = SFrameStats();
        return frameStats;
    }

    void FetchPoolStats(std::vector<SPoolStats>& poolStats)
    {
        CryAutoLock<CryCriticalSection> lock(m_statsLock);
        poolStats = m_poolStats;
        m_poolStats.clear();
    }
#endif

    STexPool* GetPool(int nWidth, int nHeight, int nMips, int nArraySize, ETEX_Format eTF, bool bIsSRGB, ETEX_Type eTT);

    STexPoolItem* GetPoolItem(int nWidth, int nHeight, int nMips, int nArraySize, ETEX_Format eTF, bool bIsSRGB, ETEX_Type eTT, bool bShouldBeCreated, const char* sName, STextureInfo* pTI = NULL, bool bCanCreate = true, bool bWaitForIdle = true);
    void ReleaseItem(STexPoolItem* pItem);
    void GarbageCollect(size_t* nCurTexPoolSize, size_t nLowerPoolLimit, int nMaxItemsToFree);

    void GetMemoryUsage(ICrySizer* pSizer);

    size_t GetInUseSize() const { return m_nDeviceMemInUse; }
    size_t GetReservedSize() const { return m_nDeviceMemReserved; }

private:
    union TexturePoolKey
    {
        struct
        {
            uint64 a, b;
        };
        struct
        {
            uint16 nWidth;
            uint16 nHeight;
            uint32 nFormat;
            uint8 nTexType;
            uint8 nMips;
            uint16 nArraySize;
        };

        TexturePoolKey(uint16 nWidth, uint16 nHeight, uint32 nFormat, uint8 nTexType, uint8 nMips, uint16 nArraySize)
        {
            memset(this, 0, sizeof(*this));
            this->nWidth = nWidth;
            this->nHeight = nHeight;
            this->nFormat = nFormat;
            this->nTexType = nTexType;
            this->nMips = nMips;
            this->nArraySize = nArraySize;
        }

        void GetMemoryUsage(ICrySizer* pSizer) const {}

        friend bool operator < (const TexturePoolKey& a, const TexturePoolKey& b)
        {
            if (a.a != b.a)
            {
                return a.a < b.a;
            }
            return a.b < b.b;
        }
    };

    enum
    {
        MaxFreePool = 64,
    };

    typedef VectorMap<TexturePoolKey, STexPool*> TexturePoolMap;

private:
    STexPool* CreatePool(int nWidth, int nHeight, int nMips, int nArraySize, D3DFormat eTF, ETEX_Type eTT);
    void FlushFree();

private:
    volatile size_t m_nDeviceMemReserved;
    volatile size_t m_nDeviceMemInUse;

#if !defined(_RELEASE)
    CryCriticalSection m_statsLock;
    bool m_bComputeStats;
    std::vector<SPoolStats> m_poolStats;
    SFrameStats m_frameStats;
#endif

    uint32 m_nTick;

    TexturePoolMap m_TexturesPools;
    STexPoolItemHdr m_FreeTexPoolItems;

#ifdef TEXSTRM_USE_FREEPOOL
    void* m_FreePool[MaxFreePool];
    size_t m_nFreePoolBegin;
    size_t m_nFreePoolEnd;
#endif
};

_inline void STexPoolItemHdr::Unlink()
{
    if (!m_Next || !m_Prev)
    {
        return;
    }
    m_Next->m_Prev = m_Prev;
    m_Prev->m_Next = m_Next;
    m_Next = m_Prev = NULL;
}

_inline void STexPoolItemHdr::Link(STexPoolItemHdr* pAfter)
{
    if (m_Next || m_Prev)
    {
        return;
    }
    m_Next = pAfter->m_Next;
    pAfter->m_Next->m_Prev = this;
    pAfter->m_Next = this;
    m_Prev = pAfter;
}

_inline void STexPoolItemHdr::UnlinkFree()
{
    if (!m_NextFree || !m_PrevFree)
    {
        return;
    }
    m_NextFree->m_PrevFree = m_PrevFree;
    m_PrevFree->m_NextFree = m_NextFree;
    m_NextFree = m_PrevFree = NULL;
}
_inline void STexPoolItemHdr::LinkFree(STexPoolItemHdr* pAfter)
{
    if (m_NextFree || m_PrevFree)
    {
        return;
    }
    m_NextFree = pAfter->m_NextFree;
    pAfter->m_NextFree->m_PrevFree = this;
    pAfter->m_NextFree = this;
    m_PrevFree = pAfter;
}

#endif // CRYINCLUDE_CRYENGINE_RENDERDLL_COMMON_TEXTURES_TEXTURESTREAMPOOL_H