MODULE showcase_primitives ;

(*
   m2SDL3 showcase, ported from SDL upstream
   examples/renderer/02-primitives/primitives.c (public domain).

   Draws a filled rectangle, 500 random points, an inset outline
   and a yellow X across the canvas every frame.

   SDL3 native form:
   - SDL_RenderRect / SDL_RenderPoints / SDL_RenderFillRect take
     SDL_FRect / SDL_FPoint records with SHORTREAL fields.
   - Point array passes as ADR(points) + count (see SDL3Render).
   - libc rand seeded from SDL_GetTicks replaces SDL_randf.
   - Callback structure flattened into a main loop; auto-quit
     after 8 s so the showcase also terminates unattended.
*)

FROM SYSTEM IMPORT ADDRESS, ADR, CARDINAL8;
FROM SDL3 IMPORT SDL_Init, SDL_Quit, SDL_Delay,
   SDL_GetTicks, SDLInitVideo;
FROM SDL3Video IMPORT WindowHandle, SDL_DestroyWindow, WindowResizable;
FROM SDL3Render IMPORT RendererHandle,
   SDL_CreateWindowAndRenderer, SDL_DestroyRenderer,
   SDL_SetRenderDrawColor, SDL_RenderClear, SDL_RenderPresent,
   SDL_SetRenderLogicalPresentation, LogicalLetterbox,
   SDL_RenderLine, SDL_RenderRect, SDL_RenderPoints,
   SDL_RenderFillRect;
FROM SDL3Rect IMPORT SDLFRect, SDLFPoint, MakeFRect, MakeFPoint;
FROM SDL3Utils IMPORT DrainEvents;
FROM libc IMPORT printf, rand, srand;

CONST FrameMs = 16; MaxMs = 8000;
CONST WinW = 640; WinH = 480; NPoints = 500;

VAR
   win: WindowHandle;
   ren: RendererHandle;
   points: ARRAY [0..NPoints-1] OF SDLFPoint;
   rect: SDLFRect;
   quit: BOOLEAN;
   start: LONGCARD;
   i: INTEGER;

BEGIN
   IF NOT SDL_Init(SDLInitVideo) THEN
      printf("showcase_primitives: SDL_Init failed\n");
      HALT(1)
   END;
   IF NOT SDL_CreateWindowAndRenderer("m2SDL3 primitives",
                                      WinW, WinH,
                                      VAL(LONGCARD, WindowResizable),
                                      win, ren) THEN
      printf("showcase_primitives: CreateWindowAndRenderer failed\n");
      SDL_Quit;
      HALT(1)
   END;
   SDL_SetRenderLogicalPresentation(ren, WinW, WinH, LogicalLetterbox);

   (* scatter the points inside the blue rectangle, as in the C code. *)
   srand(VAL(INTEGER, SDL_GetTicks()));
   FOR i := 0 TO NPoints - 1 DO
      points[i] := MakeFPoint(VAL(SHORTREAL, VAL(REAL, rand() MOD 440 + 100)),
                              VAL(SHORTREAL, VAL(REAL, rand() MOD 280 + 100)))
   END;

   printf("showcase_primitives: close window or wait 8s\n");
   quit := FALSE;
   start := SDL_GetTicks();
   WHILE NOT quit DO
      DrainEvents(quit);

      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 33), VAL(CARDINAL8, 33),
                             VAL(CARDINAL8, 33), VAL(CARDINAL8, 255));
      SDL_RenderClear(ren);

      rect := MakeFRect(VAL(SHORTREAL, 100.0), VAL(SHORTREAL, 100.0),
                        VAL(SHORTREAL, 440.0), VAL(SHORTREAL, 280.0));
      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 0), VAL(CARDINAL8, 0),
                             VAL(CARDINAL8, 255), VAL(CARDINAL8, 255));
      SDL_RenderFillRect(ren, rect);

      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 255), VAL(CARDINAL8, 0),
                             VAL(CARDINAL8, 0), VAL(CARDINAL8, 255));
      SDL_RenderPoints(ren, ADR(points), NPoints);

      rect := MakeFRect(VAL(SHORTREAL, 130.0), VAL(SHORTREAL, 130.0),
                        VAL(SHORTREAL, 380.0), VAL(SHORTREAL, 220.0));
      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 0), VAL(CARDINAL8, 255),
                             VAL(CARDINAL8, 0), VAL(CARDINAL8, 255));
      SDL_RenderRect(ren, rect);

      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 255), VAL(CARDINAL8, 255),
                             VAL(CARDINAL8, 0), VAL(CARDINAL8, 255));
      SDL_RenderLine(ren, VAL(SHORTREAL, 0.0), VAL(SHORTREAL, 0.0),
                     VAL(SHORTREAL, VAL(REAL, WinW)), VAL(SHORTREAL, VAL(REAL, WinH)));
      SDL_RenderLine(ren, VAL(SHORTREAL, 0.0), VAL(SHORTREAL, VAL(REAL, WinH)),
                     VAL(SHORTREAL, VAL(REAL, WinW)), VAL(SHORTREAL, 0.0));

      SDL_RenderPresent(ren);
      IF SDL_GetTicks() - start > MaxMs THEN quit := TRUE END;
      SDL_Delay(FrameMs)
   END;

   SDL_DestroyRenderer(ren);
   SDL_DestroyWindow(win);
   SDL_Quit;
   printf("showcase_primitives: bye\n")
END showcase_primitives.