////////////////////////////////////////////////////////////
//~ Key types

Struct(SPR_SheetKey) { ResourceKey r; };
Struct(SPR_SpanKey) { u64 v; };

#define SPR_NilSheetKey ((SPR_SheetKey) { 0 })
#define SPR_NilSpanKey ((SPR_SpanKey) { 0 })

////////////////////////////////////////////////////////////
//~ Atlas types

Struct(SPR_Atlas)
{
  SPR_Atlas *next;

  Vec2I32 dims;
  G_ResourceHandle tex;
  G_Texture2DRef tex_ref;
  Vec2I32 cur_pos;
  i32 cur_row_height;
};

////////////////////////////////////////////////////////////
//~ Ray types

#define SPR_RayKindXMacro(X)      \
  X(Origin,     .origin)          \
  X(Ap,         .ap)              \
/* ----------------------------- */

Enum(SPR_RayKind)
{
  #define X(kind_name, ...) SPR_RayKind_##kind_name,
    SPR_RayKindXMacro(X)
  #undef X
  SPR_RayKind_COUNT
};

////////////////////////////////////////////////////////////
//~ Layer types

Enum(SPR_LayerKind)
{
  SPR_LayerKind_Visual,
  SPR_LayerKind_Hidden,
};

////////////////////////////////////////////////////////////
//~ Lookup result types

Struct(SPR_Slice)
{
  Xform rays[SPR_RayKind_COUNT];

  G_Texture2DRef tex;
  Rng2 tex_rect_uv;
  Rng2 bounds;

  b32 exists;
  b32 ready;
};

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

//- Slice

Struct(SPR_SliceEntry)
{
  SPR_SliceEntry *next_in_bin;

  Xform rays[SPR_RayKind_COUNT];

  SPR_Atlas *atlas;
  Rng2 atlas_rect_uv;
  Rng2 bounds;
  Atomic64 atlas_copy_completion_target;
};

//- Span

Struct(SPR_SpanEntry)
{
  SPR_SpanEntry *next;
  SPR_SpanEntry *next_in_bin;
  SPR_SpanKey key;

  i64 from;
  i64 to;
};

Struct(SPR_SpanBin)
{
  SPR_SpanEntry *first;
};

//- Sheet

Struct(SPR_SheetEntry)
{
  SPR_SheetEntry *next_in_bin;
  SPR_SheetKey key;

  i64 slices_count;
  SPR_SliceEntry *slices;

  i64 span_bins_count;
  SPR_SpanBin *span_bins;
  SPR_SpanEntry *first_span;
  SPR_SpanEntry *last_span;

  ASE_Meta meta;
  b32 ok;
};

Struct(SPR_SheetBin)
{
  Mutex mutex;
  SPR_SheetEntry *first;
};

////////////////////////////////////////////////////////////
//~ Async cmd types

Struct(SPR_Cmd)
{
  SPR_SheetEntry *sheet;
  i64 slice_idx;
};

Struct(SPR_CmdNode)
{
  SPR_CmdNode *next;
  SPR_Cmd cmd;
};

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

Struct(SPR_AsyncCtx)
{
  i32 _;
};

Struct(SPR_Ctx)
{
  SPR_SheetBin sheet_bins[Kibi(16)];

  // FIXME: Initialize this
  G_Texture2DRef unready_tex;
  Vec2 unready_tex_dims;

  i64 atlases_count;
  SPR_Atlas *first_atlas;

  struct
  {
    Mutex mutex;
    SPR_CmdNode *first;
    SPR_CmdNode *last;
    SPR_CmdNode *first_free;
    i64 count;
  } submit;

  SPR_AsyncCtx async;
};

extern SPR_Ctx SPR;

////////////////////////////////////////////////////////////
//~ Bootstrap

void SPR_Bootstrap(void);

////////////////////////////////////////////////////////////
//~ Helpers

SPR_SheetKey SPR_SheetKeyFromResource(ResourceKey resource);
SPR_SpanKey SPR_SpanKeyFromName(String name);

String SPR_NameFromRayKind(SPR_RayKind kind);
SPR_LayerKind SPR_LayerKindFromName(String name);

////////////////////////////////////////////////////////////
//~ Lookup

SPR_Slice SPR_SliceFromSheet(SPR_SheetKey sheet_key, SPR_SpanKey span_key, i64 frame_seq);

////////////////////////////////////////////////////////////
//~ Async

void SPR_TickAsync(WaveLaneCtx *lane, AsyncFrameLaneCtx *base_async_lane_frame);