MODULE showcase_primitives ;

(*
   m2SDL showcase, ported from SDL-main
   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 -> SDL2 adaptations
   - SDL_RenderRect/RenderPoints become SDL2
     SDL_RenderDrawRect / SDL_RenderDrawPoints.
   - SDL_FPoint floats become integer SDLPoint; SDL_randf is
     replaced by libc rand seeded from SDL_GetTicks.
   - Point array passes as ADR(points) + count (see SDLRender).
   - 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 SDL2 IMPORT SDL_Init, SDL_Quit, SDL_Delay,
   SDL_GetTicks, SDL_GetTicks64, SDLInitVideo;
FROM SDLVideo IMPORT WindowHandle, SDL_DestroyWindow, WindowResizable;
FROM SDLRender IMPORT RendererHandle,
   SDL_CreateWindowAndRenderer, SDL_DestroyRenderer,
   SDL_SetRenderDrawColor, SDL_RenderClear, SDL_RenderPresent,
   SDL_RenderSetLogicalSize,
   SDL_RenderDrawLine, SDL_RenderDrawRect, SDL_RenderDrawPoints,
   SDL_RenderFillRect;
FROM SDLRect IMPORT SDLRect, SDLPoint, MakeRect, MakePoint;
FROM SDLUtils 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 SDLPoint;
   rect: SDLRect;
   quit: BOOLEAN;
   start: LONGCARD;
   i: INTEGER;

BEGIN
   IF SDL_Init(SDLInitVideo) # 0 THEN
      printf("showcase_primitives: SDL_Init failed\n");
      HALT(1)
   END;
   IF SDL_CreateWindowAndRenderer(WinW, WinH, WindowResizable,
                                  win, ren) # 0 THEN
      printf("showcase_primitives: CreateWindowAndRenderer failed\n");
      SDL_Quit;
      HALT(1)
   END;
   SDL_RenderSetLogicalSize(ren, WinW, WinH);

   (* 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] := MakePoint(rand() MOD 440 + 100, rand() MOD 280 + 100)
   END;

   printf("showcase_primitives: close window or wait 8s\n");
   quit := FALSE;
   start := SDL_GetTicks64();
   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 := MakeRect(100, 100, 440, 280);
      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_RenderDrawPoints(ren, ADR(points), NPoints);

      rect := MakeRect(130, 130, 380, 220);
      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 0), VAL(CARDINAL8, 255),
                             VAL(CARDINAL8, 0), VAL(CARDINAL8, 255));
      SDL_RenderDrawRect(ren, rect);

      SDL_SetRenderDrawColor(ren, VAL(CARDINAL8, 255), VAL(CARDINAL8, 255),
                             VAL(CARDINAL8, 0), VAL(CARDINAL8, 255));
      SDL_RenderDrawLine(ren, 0, 0, WinW, WinH);
      SDL_RenderDrawLine(ren, 0, WinH, WinW, 0);

      SDL_RenderPresent(ren);
      IF SDL_GetTicks64() - 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.