/*
* 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_POWEROF2BLOCKPACKER_H
#define CRYINCLUDE_CRYENGINE_RENDERDLL_COMMON_TEXTURES_POWEROF2BLOCKPACKER_H
#pragma once


#include <vector>                       // STL vector<>

class CPowerOf2BlockPacker
{
public:
    CTexture* m_pTexture;
    float m_fLastUsed;

public:
    // constructor
    // Arguments:
    //   dwLogHeight - e.g. specify 5 for 32, keep is small like ~ 5 or 6, don't use pixel size
    //   dwLogHeight - e.g. specify 5 for 32, keep is small like ~ 5 or 6, don't use pixel size
    CPowerOf2BlockPacker(const uint32 dwLogWidth = 0, const uint32 dwLogHeight = 0);

    ~CPowerOf2BlockPacker();

    // Arguments:
    //   dwLogHeight - e.g. specify 5 for 32
    //   dwLogHeight - e.g. specify 5 for 32
    // Returns:
    //   dwBlockID (to remove later), 0xffffffff if there was no free space
    uint32 AddBlock(const uint32 dwLogWidth, const uint32 dwLogHeight);

    // Arguments:
    //   dwBlockID - as it was returned from AddBlock()
    uint32 GetBlockInfo(const uint32 dwBlockID, uint32& dwMinX, uint32& dwMinY, uint32& dwMaxX, uint32& dwMaxY);

    void UpdateSize(int nW, int nH);

    // Arguments:
    //   dwBlockID - as it was returned from AddBlock()
    void RemoveBlock(const uint32 dwBlockID);

    // used for debugging
    // Return
    //   0xffffffff if not block was found
    uint32 GetRandomBlock() const;

    uint32 GetNumUsedBlocks() const
    {
        return m_nUsedBlocks;
    }

    void Clear();

    void FreeContainers();

private: // ----------------------------------------------------------

    struct SBlockMinMax
    {
        uint32      m_dwMinX;       // 0xffffffff if free, included
        uint32      m_dwMinY;       // not defined if free, included
        uint32      m_dwMaxX;       // not defined if free, not included
        uint32      m_dwMaxY;       // not defined if free, not included

        bool IsFree() const
        {
            return m_dwMinX == 0xffffffff;
        }

        void MarkFree()
        {
            m_dwMinX = 0xffffffff;
        }

        ~SBlockMinMax()
        {
            MarkFree();
        }
    };

    // -----------------------------------------------------------------

    std::vector<SBlockMinMax>               m_Blocks;                       //
    std::vector<uint32>                         m_BlockBitmap;          // [m_dwWidth*m_dwHeight], elements are 0xffffffff if not used
    uint32                                                  m_dwWidth;                  // >0
    uint32                                                  m_dwHeight;                 // >0
    uint32                          m_nUsedBlocks;

    // -----------------------------------------------------------------

    //
    void FillRect(const SBlockMinMax& rect, uint32 dwValue);

    bool IsFree(const SBlockMinMax& rect);

    //
    uint32 FindFreeBlockIDOrCreateNew();
};

#endif // CRYINCLUDE_CRYENGINE_RENDERDLL_COMMON_TEXTURES_POWEROF2BLOCKPACKER_H