OpenTTD Source: src/saveload/oldloader.h Source File

OpenTTD Source 13.2.1

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