/** Data of an animation group. */
class AnimGroupData
{
public:
    AnimGroupData();
    AnimGroupData(const AnimGroupData &ag);
    AnimGroupData &operator=(const AnimGroupData &ag);

    int m_iTileSize;       ///< Size of a tile for this animation group.
    int m_iAnimLength;     ///< Number of frames in an animation of this group.
    std::string m_sName;   ///< Name of the animation group.

    int m_aFirstFrames[4]; ///< Index into AnimationStorage::m_vFrames of the first frame, else \c -1.
};

/** Data of a frame in an animation. */
class FrameData
{
public:
    FrameData();
    FrameData(const FrameData &fd);
    FrameData &operator=(const FrameData &fd);

    int m_iSound;          ///< If non-zero, sound to play.
    int m_iNumberElements; ///< Number of sprite elements in the frame.
    int m_iFirstElement;   ///< Index of the first sprite element in AnimationStorage::m_vElements.
};

/** Flags of a sprite element. */
enum ElementFlags
{
    ELM_FLIP_VERT = 0x1, ///< Flip sprite vertically.
    ELM_FLIP_HOR  = 0x2, ///< Flip sprite horizontally.
    ELM_ALPHA_50  = 0x4, ///< Apply alpha 50%.
    ELM_ALPHA_75  = 0x8, ///< Apply alpha 75%.
};

/** Data of a sprite element in a frame. */
class ElementData
{
public:
    ElementData();
    ElementData(const ElementData &ed);
    ElementData &operator=(const ElementData &ed);

    int m_iSprite;
    int m_iXoffset;
    int m_iYoffset;
    int m_iLayerClass; ///< Class of the display condition.
    int m_iLayerId;    ///< Value of the display condition.
    int m_iFlags;      ///< Flags, @see ElementFlags for the fields.
};

/** Data of a sprite, used in an element. */
class SpriteData
{
public:
    SpriteData();
    SpriteData(const SpriteData &sd);
    SpriteData &operator=(const SpriteData &sd);

    int m_iWidth;
    int m_iHeight;
    int m_iDataLength; ///< Number of bytes in AnimationStorage::m_pSpriteData for this sprite.
    int m_iDataOffset; ///< Offset of the first byte in AnimationStorage::m_pSpriteData.
};
class AnimationStorage
{
public:
    AnimationStorage();

    bool LoadFile(Input &oInput);

    std::vector<AnimGroupData> m_vGroupedAnims;
    std::vector<FrameData> m_vFrames;
    std::vector<ElementData> m_vElements;
    std::vector<SpriteData> m_vSprites;
    unsigned char *m_pSpriteData;
    size_t m_iSpriteDataSize;

private:
    bool LoadAnimGroup(AnimGroupData &oAnimGrp, int iFramesUsed, Input &oInput);
    bool LoadFrame(FrameData &oFrame, int &iElementsUsed, int iSpritesUsed, Input &oInput);
    bool LoadSprite(SpriteData &oSprite, int &iSpriteDataUsed, oInput &oInput);
};