src/unused/xstreams_sdl.pas

   1 // special stream classes
   2 {$MODE OBJFPC}
   3 {$R+}
   4 unit xstreams_sdl;
   5
   6 interface
   7
   8 uses
   9   SysUtils, Classes, xstreams;
  10
  11
  12 type
  13   // ïîòîê-îá¸ðòêà äëÿ SDL_RWops
  14   TSFSSDLStream = class(TStream)
  15   protected
  16     fRW: PSDL_RWops;      // SDL-íàÿ ïðîêëàäêà
  17     fFreeSource: Boolean; // óáèâàòü èñõîäíèê ïðè ïîìèðàíèè?
  18
  19   public
  20     constructor Create (aSrc: PSDL_RWops; aFreeSource: Boolean=true);
  21     destructor Destroy (); override;
  22
  23     function Read (var buffer; count: LongInt): LongInt; override;
  24     function Write (const buffer; count: LongInt): LongInt; override;
  25     function Seek (const offset: Int64; origin: TSeekOrigin): Int64; override;
  26   end;
  27
  28
  29 implementation
  30
  31
  32 { TSFSSDLStream }
  33 constructor TSFSSDLStream.Create (aSrc: PSDL_RWops; aFreeSource: Boolean=true);
  34 begin
  35   inherited Create();
  36   //ASSERT(aSrc <> nil);
  37   fRW := aSrc;
  38   fFreeSource := aFreeSource;
  39 end;
  40
  41 destructor TSFSSDLStream.Destroy ();
  42 begin
  43   if fFreeSource and (fRW <> nil) then SDL_FreeRW(fRW);
  44   inherited Destroy();
  45 end;
  46
  47 function TSFSSDLStream.Read (var buffer; count: LongInt): LongInt;
  48 begin
  49   if (fRW = nil) or (count <= 0) then begin result := 0; exit; end;
  50   result := SDL_RWread(fRW, @buffer, 1, count);
  51 end;
  52
  53 function TSFSSDLStream.Write (const buffer; count: LongInt): LongInt;
  54 begin
  55   if (fRW = nil) or (count <= 0) then begin result := 0; exit; end;
  56   result := SDL_RWwrite(fRW, @buffer, 1, count);
  57 end;
  58
  59 function TSFSSDLStream.Seek (const offset: Int64; origin: TSeekOrigin): Int64;
  60 var
  61   ss: Integer;
  62 begin
  63   if fRW = nil then begin result := 0; exit; end;
  64   case origin of
  65     soBeginning: ss := RW_SEEK_SET;
  66     soCurrent: ss := RW_SEEK_CUR;
  67     soEnd: ss := RW_SEEK_END;
  68     else raise XStreamError.Create('invalid Seek() call');
  69     // äðóãèõ íå áûâàåò. à ó êîãî áûâàåò, òîìó ÿ íå äîêòîð.
  70   end;
  71   result := SDL_RWseek(fRW, offset, ss);
  72   if result = -1 then raise XStreamError.Create('Seek() error');
  73 end;
  74
  75
  76 end.