////////////////////////////////////////////////////////////
//~ Texture types

Struct(S_Texture)
{
    b32 valid;
    b32 loaded;
    GPU_Resource *gpu_texture;
    u32 width;
    u32 height;
};

extern Readonly S_Texture S_NilTexture;

////////////////////////////////////////////////////////////
//~ Sheet types

Struct(S_Frame)
{
    u32 index;
    f64 duration;
    ClipRect clip;
};

Struct(S_Span)
{
    S_Span *next_in_bin;
    u64 hash;
    String name;
    u32 start;
    u32 end;
};

Struct(S_SpanBin)
{
    S_Span *first;
    S_Span *last;
};

Struct(S_Slice)
{
    /* If 1, this slice was not copied over from another frame in the sprite sheet */
    b32 is_original;

    /* If 1, the slice has a corresponding '.ray' slice affecting the 'dir' fields */
    b32 has_dir;

    /* Values are in the range -0.5 (top / left edge) -> +0.5 (bottom / right edge) */
    Rect rect;
    Vec2 center;
    Vec2 dir;

    /* '_px' values retain the original sprite pixel dimensions */
    Rect rect_px;
    Vec2 center_px;
    Vec2 dir_px;
};

Struct(S_SliceGroup)
{
    S_SliceGroup *next_in_bin;
    u64 hash;
    String name;
    S_Slice *slices;
};

Struct(S_SliceGroupBin)
{
    S_SliceGroup *first;
    S_SliceGroup *last;
};

Struct(S_Sheet)
{
    b32 valid;
    b32 loaded;
    Vec2 image_size;
    Vec2 frame_size;

    u32 frames_count;
    S_Frame *frames;

    u32 spans_count;
    S_Span *spans;

    u32 slice_groups_count;
    S_SliceGroup *slice_groups;

    u32 span_bins_count;
    S_SpanBin *span_bins;

    u32 slice_group_bins_count;
    S_SliceGroupBin *slice_group_bins;
};

extern Readonly S_Sheet S_NilSheet;

////////////////////////////////////////////////////////////
//~ Cache types

Struct(S_Entry)
{
    S_Entry *next_in_bin;

    S_Texture texture;
    S_Sheet sheet;

    Atomic32 texture_touched;
    Atomic32 sheet_touched;

    ResourceKey resource;
    Fence texture_ready_fence;
    Fence sheet_ready_fence;
};

Struct(S_EntryBin)
{
    S_Entry *first;
    S_Entry *last;
    Mutex mutex;
};

////////////////////////////////////////////////////////////
//~ State types

#define S_EntryBinsCount 1024

Struct(S_SharedState)
{
    S_EntryBin entry_bins[S_EntryBinsCount];
} extern S_shared_state;

////////////////////////////////////////////////////////////
//~ Load jobs

JobDecl(S_LoadTexture, { S_Entry *entry; });
JobDecl(S_LoadSheet, { S_Entry *entry; });

////////////////////////////////////////////////////////////
//~ Cache operations

Enum(S_FetchFlag)
{
    S_FetchFlag_None    = 0,
    S_FetchFlag_Texture = (1 << 0),
    S_FetchFlag_Sheet   = (1 << 1),
};

S_Entry *S_FetchEntry(ResourceKey resource, JobPoolId pool, S_FetchFlag flags);

////////////////////////////////////////////////////////////
//~ Sprite data retrieval operations

S_Texture *S_TextureFromResource(ResourceKey resource);
S_Texture *S_TextureFromResourceAsync(ResourceKey resource);

S_Sheet *S_SheetFromResource(ResourceKey resource);
S_Sheet *S_SheetFromResourceAsync(ResourceKey resource);

////////////////////////////////////////////////////////////
//~ Sheet access operations

S_Span S_SpanFromName(S_Sheet *sheet, String name);
S_Frame S_FrameFromIndex(S_Sheet *sheet, u64 index);
S_Slice S_SliceFromName(S_Sheet *sheet, String name, u64 frame_index);