src/sheditor/xstreams_sdl.pas

   1 (* Copyright (C)  DooM 2D:Forever Developers
   2  *
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 3 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  *)
  16 // special stream classes
  17 {$MODE DELPHI}
  18 {$R+}
  19 unit xstreams_sdl;
  20
  21 interface
  22
  23 uses
  24   SysUtils, Classes, xstreams;
  25
  26
  27 type
  28   // ïîòîê-îá¸ðòêà äëÿ SDL_RWops
  29   TSFSSDLStream = class(TStream)
  30   protected
  31     fRW: PSDL_RWops;      // SDL-íàÿ ïðîêëàäêà
  32     fFreeSource: Boolean; // óáèâàòü èñõîäíèê ïðè ïîìèðàíèè?
  33
  34   public
  35     constructor Create (aSrc: PSDL_RWops; aFreeSource: Boolean=true);
  36     destructor Destroy (); override;
  37
  38     function Read (var buffer; count: LongInt): LongInt; override;
  39     function Write (const buffer; count: LongInt): LongInt; override;
  40     function Seek (const offset: Int64; origin: TSeekOrigin): Int64; override;
  41   end;
  42
  43
  44 implementation
  45
  46
  47 { TSFSSDLStream }
  48 constructor TSFSSDLStream.Create (aSrc: PSDL_RWops; aFreeSource: Boolean=true);
  49 begin
  50   inherited Create();
  51   //ASSERT(aSrc <> nil);
  52   fRW := aSrc;
  53   fFreeSource := aFreeSource;
  54 end;
  55
  56 destructor TSFSSDLStream.Destroy ();
  57 begin
  58   if fFreeSource and (fRW <> nil) then SDL_FreeRW(fRW);
  59   inherited Destroy();
  60 end;
  61
  62 function TSFSSDLStream.Read (var buffer; count: LongInt): LongInt;
  63 begin
  64   if (fRW = nil) or (count <= 0) then begin result := 0; exit; end;
  65   result := SDL_RWread(fRW, @buffer, 1, count);
  66 end;
  67
  68 function TSFSSDLStream.Write (const buffer; count: LongInt): LongInt;
  69 begin
  70   if (fRW = nil) or (count <= 0) then begin result := 0; exit; end;
  71   result := SDL_RWwrite(fRW, @buffer, 1, count);
  72 end;
  73
  74 function TSFSSDLStream.Seek (const offset: Int64; origin: TSeekOrigin): Int64;
  75 var
  76   ss: Integer;
  77 begin
  78   if fRW = nil then begin result := 0; exit; end;
  79   case origin of
  80     soBeginning: ss := RW_SEEK_SET;
  81     soCurrent: ss := RW_SEEK_CUR;
  82     soEnd: ss := RW_SEEK_END;
  83     else raise XStreamError.Create('invalid Seek() call');
  84     // äðóãèõ íå áûâàåò. à ó êîãî áûâàåò, òîìó ÿ íå äîêòîð.
  85   end;
  86   result := SDL_RWseek(fRW, offset, ss);
  87   if result = -1 then raise XStreamError.Create('Seek() error');
  88 end;
  89
  90
  91 end.