src/saveload/oldloader.h

   1 /* $Id: oldloader.h 23595 2011-12-19 17:48:04Z rubidium $ */
   2
   3 /*
   4  * This file is part of OpenTTD.
   5  * 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.
   6  * 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.
   7  * 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/>.
   8  */
   9
  10 /** @file oldloader.h Declarations of strctures and function used in loader of old savegames */
  11
  12 #ifndef OLDLOADER_H
  13 #define OLDLOADER_H
  14
  15 #include "saveload.h"
  16 #include "../tile_type.h"
  17
  18 static const uint BUFFER_SIZE = 4096;
  19 static const uint OLD_MAP_SIZE = 256 * 256;
  20
  21 struct LoadgameState {
  22         FILE *file;
  23
  24         uint chunk_size;
  25
  26         bool decoding;
  27         byte decode_char;
  28
  29         uint buffer_count;
  30         uint buffer_cur;
  31         byte buffer[BUFFER_SIZE];
  32
  33         uint total_read;
  34 };
  35
  36 /* OldChunk-Type */
  37 enum OldChunkType {
  38         OC_SIMPLE    = 0,
  39         OC_NULL      = 1,
  40         OC_CHUNK     = 2,
  41         OC_ASSERT    = 3,
  42         /* 4 bits allocated (16 max) */
  43
  44         OC_TTD       = 1 << 4, ///< chunk is valid ONLY for TTD savegames
  45         OC_TTO       = 1 << 5, ///< -//- TTO (default is neither of these)
  46         /* 4 bits allocated */
  47
  48         OC_VAR_I8    = 1 << 8,
  49         OC_VAR_U8    = 2 << 8,
  50         OC_VAR_I16   = 3 << 8,
  51         OC_VAR_U16   = 4 << 8,
  52         OC_VAR_I32   = 5 << 8,
  53         OC_VAR_U32   = 6 << 8,
  54         OC_VAR_I64   = 7 << 8,
  55         OC_VAR_U64   = 8 << 8,
  56         /* 8 bits allocated (256 max) */
  57
  58         OC_FILE_I8   = 1 << 16,
  59         OC_FILE_U8   = 2 << 16,
  60         OC_FILE_I16  = 3 << 16,
  61         OC_FILE_U16  = 4 << 16,
  62         OC_FILE_I32  = 5 << 16,
  63         OC_FILE_U32  = 6 << 16,
  64         /* 8 bits allocated (256 max) */
  65
  66         OC_INT8      = OC_VAR_I8   | OC_FILE_I8,
  67         OC_UINT8     = OC_VAR_U8   | OC_FILE_U8,
  68         OC_INT16     = OC_VAR_I16  | OC_FILE_I16,
  69         OC_UINT16    = OC_VAR_U16  | OC_FILE_U16,
  70         OC_INT32     = OC_VAR_I32  | OC_FILE_I32,
  71         OC_UINT32    = OC_VAR_U32  | OC_FILE_U32,
  72
  73         OC_TILE      = OC_VAR_U32  | OC_FILE_U16,
  74
  75         /**
  76          * Dereference the pointer once before writing to it,
  77          * so we do not have to use big static arrays.
  78          */
  79         OC_DEREFERENCE_POINTER = 1 << 31,
  80
  81         OC_END       = 0, ///< End of the whole chunk, all 32 bits set to zero
  82 };
  83
  84 DECLARE_ENUM_AS_BIT_SET(OldChunkType)
  85
  86 typedef bool OldChunkProc(LoadgameState *ls, int num);
  87
  88 struct OldChunks {
  89         OldChunkType type;   ///< Type of field
  90         uint32 amount;       ///< Amount of fields
  91
  92         void *ptr;           ///< Pointer where to save the data (may only be set if offset is 0)
  93         uint offset;         ///< Offset from basepointer (may only be set if ptr is NULL)
  94         OldChunkProc *proc;  ///< Pointer to function that is called with OC_CHUNK
  95 };
  96
  97 /* If it fails, check lines above.. */
  98 assert_compile(sizeof(TileIndex) == 4);
  99
 100 extern uint _bump_assert_value;
 101 byte ReadByte(LoadgameState *ls);
 102 bool LoadChunk(LoadgameState *ls, void *base, const OldChunks *chunks);
 103
 104 bool LoadTTDMain(LoadgameState *ls);
 105 bool LoadTTOMain(LoadgameState *ls);
 106
 107 static inline uint16 ReadUint16(LoadgameState *ls)
 108 {
 109         byte x = ReadByte(ls);
 110         return x | ReadByte(ls) << 8;
 111 }
 112
 113 static inline uint32 ReadUint32(LoadgameState *ls)
 114 {
 115         uint16 x = ReadUint16(ls);
 116         return x | ReadUint16(ls) << 16;
 117 }
 118
 119 /* Help:
 120  *  - OCL_SVAR: load 'type' to offset 'offset' in a struct of type 'base', which must also
 121  *       be given via base in LoadChunk() as real pointer
 122  *  - OCL_VAR: load 'type' to a global var
 123  *  - OCL_END: every struct must end with this
 124  *  - OCL_NULL: read 'amount' of bytes and send them to /dev/null or something
 125  *  - OCL_CHUNK: load another proc to load a part of the savegame, 'amount' times
 126  *  - OCL_ASSERT: to check if we are really at the place we expect to be.. because old savegames are too binary to be sure ;)
 127  */
 128 #define OCL_SVAR(type, base, offset)         { type,                 1,    NULL, (uint)cpp_offsetof(base, offset), NULL }
 129 #define OCL_VAR(type, amount, pointer)       { type,            amount, pointer,    0,                             NULL }
 130 #define OCL_END()                            { OC_END,               0,    NULL,    0,                             NULL }
 131 #define OCL_CNULL(type, amount)              { OC_NULL | type,  amount,    NULL,    0,                             NULL }
 132 #define OCL_CCHUNK(type, amount, proc)       { OC_CHUNK | type, amount,    NULL,    0,                             proc }
 133 #define OCL_ASSERT(type, size)               { OC_ASSERT | type,     1,    NULL, size,                             NULL }
 134 #define OCL_NULL(amount)        OCL_CNULL((OldChunkType)0, amount)
 135 #define OCL_CHUNK(amount, proc) OCL_CCHUNK((OldChunkType)0, amount, proc)
 136
 137 #endif /* OLDLOADER_H */