// ----------------------------------------------------------------------------
// game ui

typedef struct guiskin_t {
    void (*drawrect)(void* userdata, const char *skin, vec4 rect);
    void (*getskinsize)(void* userdata, const char *skin, vec2 *size);
    void (*getscissorrect)(void* userdata, const char *skin, vec4 rect, vec4 *dims);
    bool (*ismouseinrect)(void* userdata, const char *skin, vec4 rect);
    void (*free)(void* userdata);
    void *userdata;
} guiskin_t;

API void    gui_pushskin(guiskin_t skin);
API void*       gui_userdata();
API vec2        gui_getskinsize(const char *skin);
API bool        gui_ismouseinrect(const char *skin, vec4 rect);
// --
API void        gui_panel_id(int id, vec4 rect, const char *skin);
API void            gui_rect_id(int id, vec4 rect, const char *skin);
API bool            gui_button_id(int id, vec4 rect, const char *skin);
API bool            gui_slider_id(int id, vec4 rect, const char *skin, float min, float max, float step, float *value);
API void        gui_panel_end();
API void    gui_popskin();

// helpers
#define gui_panel(...) gui_panel_id(__LINE__, __VA_ARGS__)
#define gui_rect(...) gui_rect_id(__LINE__, __VA_ARGS__)
#define gui_button(...) gui_button_id(__LINE__, __VA_ARGS__)
#define gui_slider(...) gui_slider_id(__LINE__, __VA_ARGS__)

// default renderers

/// skinned
/* The skinning engine depends on an Aseprite asset with slices set up.
   While you can specify your own skins for various GUI widgets, some
   skin variants are hardcoded and expected to be present in your asset:

   gui_panel():
    - "panel" (overridable)
   gui_button():
    - "button" (base overridable)
      - "_hover" (ex. "scarybtn_hover")
      - "_press"
   gui_rect():
    - no defaults, always pass your own skin/slice name
   gui_slider():
    - "slider" (overridable)
    - "slider_cursor" (partially overridable, ex. "bigslider_cursor")
      - "_hover" (ex. "slider_cursor_hover")
      - "_press"
*/
typedef struct skinned_t {
    atlas_t atlas;
    float scale;
} skinned_t;

API guiskin_t gui_skinned(const char *asefile, float scale);