diff options
Diffstat (limited to 'src/saveload/oldloader.cpp')
-rw-r--r-- | src/saveload/oldloader.cpp | 98 |
1 files changed, 74 insertions, 24 deletions
diff --git a/src/saveload/oldloader.cpp b/src/saveload/oldloader.cpp index 4b7af3a42..2411a675e 100644 --- a/src/saveload/oldloader.cpp +++ b/src/saveload/oldloader.cpp @@ -17,12 +17,13 @@ #include "oldloader.h" enum { - HEADER_SIZE = 49, + TTO_HEADER_SIZE = 41, + TTD_HEADER_SIZE = 49, }; uint32 _bump_assert_value; -static inline OldChunkType GetOldChunkType(OldChunkType type) {return (OldChunkType)GB(type, 0, 8);} +static inline OldChunkType GetOldChunkType(OldChunkType type) {return (OldChunkType)GB(type, 0, 4);} static inline OldChunkType GetOldChunkVarType(OldChunkType type) {return (OldChunkType)(GB(type, 8, 8) << 8);} static inline OldChunkType GetOldChunkFileType(OldChunkType type) {return (OldChunkType)(GB(type, 16, 8) << 16);} @@ -101,12 +102,17 @@ byte ReadByte(LoadgameState *ls) */ bool LoadChunk(LoadgameState *ls, void *base, const OldChunks *chunks) { - const OldChunks *chunk = chunks; byte *base_ptr = (byte*)base; - while (chunk->type != OC_END) { + for (const OldChunks *chunk = chunks; chunk->type != OC_END; chunk++) { + if (((chunk->type & OC_TTD) && (_savegame_type == SGT_TTO)) || + ((chunk->type & OC_TTO) && (_savegame_type != SGT_TTO))) { + /* TTD(P)-only chunk, but TTO savegame || TTO-only chunk, but TTD/TTDP savegame */ + continue; + } + byte *ptr = (byte*)chunk->ptr; - if ((chunk->type & OC_DEREFERENCE_POINTER) != 0) ptr = *(byte**)ptr; + if (chunk->type & OC_DEREFERENCE_POINTER) ptr = *(byte**)ptr; for (uint i = 0; i < chunk->amount; i++) { if (ls->failed) return false; @@ -164,8 +170,6 @@ bool LoadChunk(LoadgameState *ls, void *base, const OldChunks *chunks) if (chunk->amount > 1 && chunk->ptr != NULL) ptr += CalcOldVarLen(chunk->type); } } - - chunk++; } return true; @@ -194,30 +198,72 @@ static void InitLoading(LoadgameState *ls) _settings_game.construction.freeform_edges = false; // disable so we can convert map array (SetTileType is still used) } - - /** * Verifies the title has a valid checksum * @param title title and checksum * @return true iff the title is valid - * @note the title (incl. checksum) has to be at least 49 (HEADER_SIZE) bytes long! + * @note the title (incl. checksum) has to be at least 41/49 (HEADER_SIZE) bytes long! */ -static bool VerifyOldNameChecksum(char *title) +static bool VerifyOldNameChecksum(char *title, uint len) { uint16 sum = 0; - for (uint i = 0; i < HEADER_SIZE - 2; i++) { + for (uint i = 0; i < len - 2; i++) { sum += title[i]; sum = ROL(sum, 1); } sum ^= 0xAAAA; // computed checksum - uint16 sum2 = title[HEADER_SIZE - 2]; // checksum in file - SB(sum2, 8, 8, title[HEADER_SIZE - 1]); + uint16 sum2 = title[len - 2]; // checksum in file + SB(sum2, 8, 8, title[len - 1]); return sum == sum2; } +static inline bool CheckOldSavegameType(FILE *f, char *temp, const char *last, uint len) +{ + assert(last - temp + 1 >= len); + + fseek(f, 0, SEEK_SET); + if (fread(temp, 1, len, f) != len) { + temp[0] = '\0'; // if reading failed, make the name empty + return false; + } + + bool ret = VerifyOldNameChecksum(temp, len); + temp[len - 2] = '\0'; // name is nul-terminated in savegame, but it's better to be sure + + return ret; +} + +assert_compile(TTD_HEADER_SIZE >= TTO_HEADER_SIZE); +static SavegameType DetermineOldSavegameType(FILE *f, char *title, const char *last) +{ + char temp[TTD_HEADER_SIZE]; + + SavegameType type = SGT_TTO; + + if (!CheckOldSavegameType(f, temp, lastof(temp), TTO_HEADER_SIZE)) { + type = SGT_TTD; + if (!CheckOldSavegameType(f, temp, lastof(temp), TTD_HEADER_SIZE)) { + type = SGT_INVALID; + } + } + + if (title != NULL) { + switch (type) { + case SGT_TTO: title = strecpy(title, "(TTO) ", last); break; + case SGT_TTD: title = strecpy(title, "(TTD) ", last); break; + default: title = strecpy(title, "(broken) ", last); break; + } + title = strecpy(title, temp, last); + } + + return type; +} + +typedef bool LoadOldMainProc(LoadgameState *ls); + bool LoadOldSaveGame(const char *file) { LoadgameState ls; @@ -234,8 +280,19 @@ bool LoadOldSaveGame(const char *file) return false; } - char temp[HEADER_SIZE]; - if (fread(temp, 1, HEADER_SIZE, ls.file) != HEADER_SIZE || !VerifyOldNameChecksum(temp) || !LoadOldMain(&ls)) { + SavegameType type = DetermineOldSavegameType(ls.file, NULL, NULL); + + LoadOldMainProc *proc = NULL; + + switch (type) { + case SGT_TTO: proc = &LoadTTOMain; break; + case SGT_TTD: proc = &LoadTTDMain; break; + default: break; + } + + _savegame_type = type; + + if (proc == NULL || !proc(&ls)) { SetSaveLoadError(STR_GAME_SAVELOAD_ERROR_DATA_INTEGRITY_CHECK_FAILED); fclose(ls.file); return false; @@ -249,23 +306,16 @@ bool LoadOldSaveGame(const char *file) void GetOldSaveGameName(const char *path, const char *file, char *title, const char *last) { char filename[MAX_PATH]; - char temp[HEADER_SIZE]; snprintf(filename, lengthof(filename), "%s" PATHSEP "%s", path, file); FILE *f = fopen(filename, "rb"); - temp[0] = '\0'; // name is nul-terminated in savegame ... if (f == NULL) { *title = '\0'; return; } - bool broken = (fread(temp, 1, HEADER_SIZE, f) != HEADER_SIZE || !VerifyOldNameChecksum(temp)); - - temp[HEADER_SIZE - 2] = '\0'; // ... but it's better to be sure - - if (broken) title = strecpy(title, "(broken) ", last); - title = strecpy(title, temp, last); + DetermineOldSavegameType(f, title, last); fclose(f); } |