DEFINITION MODULE SDLUtils ;

(*
   m2SDL - small pure-Modula-2 helpers over the FOR "C" bindings.
   CStrToM2 copies NUL-terminated C strings (ADDRESS) into
   Modula-2 CHAR arrays (NUL-terminated, truncated to fit).
   PollM2Event decodes one queued SDL_Event into a small record:
   SDL2 puts the Uint32 type at offset 0 of every event, and for
   key events the Sint32 keysym.sym at offset 20 (see <SDL_events.h>
   and <SDL_keyboard.h>). DrainEvents pumps the queue and reports
   whether a quit event was seen.
*)

FROM SYSTEM IMPORT ADDRESS;

EXPORT UNQUALIFIED
   EventKind, M2Event,
   CStrToM2, GetErrorString, PollM2Event, DrainEvents;

TYPE
   EventKind = (evQuit, evKey, evOther);
   M2Event = RECORD
      kind: EventKind;
      sym: INTEGER;      (* valid when kind = evKey *)
      pressed: BOOLEAN;  (* valid when kind = evKey *)
   END;

PROCEDURE CStrToM2 (src: ADDRESS; VAR dst: ARRAY OF CHAR);
PROCEDURE GetErrorString (VAR buf: ARRAY OF CHAR);
PROCEDURE PollM2Event (VAR ev: M2Event) : BOOLEAN;
PROCEDURE DrainEvents (VAR quit: BOOLEAN);

END SDLUtils.