IMPLEMENTATION MODULE SDLUtils ;

FROM SYSTEM IMPORT ADDRESS, ADR;
FROM SDL2 IMPORT SDL_GetError;
FROM SDLEvents IMPORT SDL_PollEvent, EventQuit, EventBufferBytes;
FROM libc IMPORT strlen, strncpy;

PROCEDURE CStrToM2 (src: ADDRESS; VAR dst: ARRAY OF CHAR);
VAR n: CARDINAL;
BEGIN
   IF HIGH(dst) < 0 THEN RETURN END;
   IF src = NIL THEN dst[0] := 0C; RETURN END;
   (* strlen returns CSIZE_T; VAL converts without range check. *)
   n := VAL(CARDINAL, strlen(src));
   IF n > HIGH(dst) THEN n := HIGH(dst) END;
   strncpy(ADR(dst), src, n);
   IF n <= HIGH(dst) THEN dst[n] := 0C END
END CStrToM2;

PROCEDURE GetErrorString (VAR buf: ARRAY OF CHAR);
BEGIN
   CStrToM2(SDL_GetError(), buf)
END GetErrorString;

PROCEDURE DrainEvents (VAR quit: BOOLEAN);
VAR
   buf: ARRAY [0..EventBufferBytes-1] OF CHAR;
   t: CARDINAL;
BEGIN
   WHILE SDL_PollEvent(ADR(buf)) # 0 DO
      t := VAL(CARDINAL, ORD(buf[0]))
         + VAL(CARDINAL, ORD(buf[1])) * 256
         + VAL(CARDINAL, ORD(buf[2])) * 65536
         + VAL(CARDINAL, ORD(buf[3])) * 16777216;
      IF t = EventQuit THEN quit := TRUE END
   END
END DrainEvents;

END SDLUtils.