oldloader.h

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00001 /* $Id: oldloader.h 20430 2010-08-09 21:48:19Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #ifndef OLDLOADER_H
00013 #define OLDLOADER_H
00014 
00015 #include "saveload.h"
00016 #include "../tile_type.h"
00017 
00018 enum {
00019   BUFFER_SIZE = 4096,
00020   OLD_MAP_SIZE = 256 * 256,
00021 };
00022 
00023 struct LoadgameState {
00024   FILE *file;
00025 
00026   uint chunk_size;
00027 
00028   bool decoding;
00029   byte decode_char;
00030 
00031   uint buffer_count;
00032   uint buffer_cur;
00033   byte buffer[BUFFER_SIZE];
00034 
00035   uint total_read;
00036 };
00037 
00038 /* OldChunk-Type */
00039 enum OldChunkType {
00040   OC_SIMPLE    = 0,
00041   OC_NULL      = 1,
00042   OC_CHUNK     = 2,
00043   OC_ASSERT    = 3,
00044   /* 4 bits allocated (16 max) */
00045 
00046   OC_TTD       = 1 << 4, 
00047   OC_TTO       = 1 << 5, 
00048   /* 4 bits allocated */
00049 
00050   OC_VAR_I8    = 1 << 8,
00051   OC_VAR_U8    = 2 << 8,
00052   OC_VAR_I16   = 3 << 8,
00053   OC_VAR_U16   = 4 << 8,
00054   OC_VAR_I32   = 5 << 8,
00055   OC_VAR_U32   = 6 << 8,
00056   OC_VAR_I64   = 7 << 8,
00057   OC_VAR_U64   = 8 << 8,
00058   /* 8 bits allocated (256 max) */
00059 
00060   OC_FILE_I8   = 1 << 16,
00061   OC_FILE_U8   = 2 << 16,
00062   OC_FILE_I16  = 3 << 16,
00063   OC_FILE_U16  = 4 << 16,
00064   OC_FILE_I32  = 5 << 16,
00065   OC_FILE_U32  = 6 << 16,
00066   /* 8 bits allocated (256 max) */
00067 
00068   OC_INT8      = OC_VAR_I8   | OC_FILE_I8,
00069   OC_UINT8     = OC_VAR_U8   | OC_FILE_U8,
00070   OC_INT16     = OC_VAR_I16  | OC_FILE_I16,
00071   OC_UINT16    = OC_VAR_U16  | OC_FILE_U16,
00072   OC_INT32     = OC_VAR_I32  | OC_FILE_I32,
00073   OC_UINT32    = OC_VAR_U32  | OC_FILE_U32,
00074 
00075   OC_TILE      = OC_VAR_U32  | OC_FILE_U16,
00076 
00081   OC_DEREFERENCE_POINTER = 1 << 31,
00082 
00083   OC_END       = 0 
00084 };
00085 
00086 DECLARE_ENUM_AS_BIT_SET(OldChunkType);
00087 
00088 typedef bool OldChunkProc(LoadgameState *ls, int num);
00089 
00090 struct OldChunks {
00091   OldChunkType type;   
00092   uint32 amount;       
00093 
00094   void *ptr;           
00095   uint offset;         
00096   OldChunkProc *proc;  
00097 };
00098 
00099 /* If it fails, check lines above.. */
00100 assert_compile(sizeof(TileIndex) == 4);
00101 
00102 extern uint _bump_assert_value;
00103 byte ReadByte(LoadgameState *ls);
00104 bool LoadChunk(LoadgameState *ls, void *base, const OldChunks *chunks);
00105 
00106 bool LoadTTDMain(LoadgameState *ls);
00107 bool LoadTTOMain(LoadgameState *ls);
00108 
00109 static inline uint16 ReadUint16(LoadgameState *ls)
00110 {
00111   byte x = ReadByte(ls);
00112   return x | ReadByte(ls) << 8;
00113 }
00114 
00115 static inline uint32 ReadUint32(LoadgameState *ls)
00116 {
00117   uint16 x = ReadUint16(ls);
00118   return x | ReadUint16(ls) << 16;
00119 }
00120 
00121 /* Help:
00122  *  - OCL_SVAR: load 'type' to offset 'offset' in a struct of type 'base', which must also
00123  *       be given via base in LoadChunk() as real pointer
00124  *  - OCL_VAR: load 'type' to a global var
00125  *  - OCL_END: every struct must end with this
00126  *  - OCL_NULL: read 'amount' of bytes and send them to /dev/null or something
00127  *  - OCL_CHUNK: load another proc to load a part of the savegame, 'amount' times
00128  *  - OCL_ASSERT: to check if we are really at the place we expect to be.. because old savegames are too binary to be sure ;)
00129  */
00130 #define OCL_SVAR(type, base, offset)         { type,                 1,    NULL, (uint)cpp_offsetof(base, offset), NULL }
00131 #define OCL_VAR(type, amount, pointer)       { type,            amount, pointer,    0,                             NULL }
00132 #define OCL_END()                            { OC_END,               0,    NULL,    0,                             NULL }
00133 #define OCL_CNULL(type, amount)              { OC_NULL | type,  amount,    NULL,    0,                             NULL }
00134 #define OCL_CCHUNK(type, amount, proc)       { OC_CHUNK | type, amount,    NULL,    0,                             proc }
00135 #define OCL_ASSERT(type, size)               { OC_ASSERT | type,     1,    NULL, size,                             NULL }
00136 #define OCL_NULL(amount)        OCL_CNULL((OldChunkType)0, amount)
00137 #define OCL_CHUNK(amount, proc) OCL_CCHUNK((OldChunkType)0, amount, proc)
00138 
00139 #endif /* OLDLOADER_H */

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