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author | sluicebox | 2019-02-12 14:26:55 -0800 |
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committer | Filippos Karapetis | 2019-02-13 22:10:41 +0200 |
commit | a6bcf88cd4a904f4b4898934b7b8becc7ff024c2 (patch) | |
tree | c16efc3961f770ba026afc23650ae5845321c3d7 | |
parent | 0a68bf7768b291acfae60e179d492db441f07dea (diff) | |
download | scummvm-rg350-a6bcf88cd4a904f4b4898934b7b8becc7ff024c2.tar.gz scummvm-rg350-a6bcf88cd4a904f4b4898934b7b8becc7ff024c2.tar.bz2 scummvm-rg350-a6bcf88cd4a904f4b4898934b7b8becc7ff024c2.zip |
SCI: Fix ECO1 column puzzle, bug #10885
Works around a script bug that prevents the game from being completed
-rw-r--r-- | engines/sci/engine/script_patches.cpp | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/engines/sci/engine/script_patches.cpp b/engines/sci/engine/script_patches.cpp index bfb85fc40a..c516508f78 100644 --- a/engines/sci/engine/script_patches.cpp +++ b/engines/sci/engine/script_patches.cpp @@ -122,6 +122,7 @@ static const char *const selectorNameTable[] = { "at", // Longbow, QFG4 "owner", // Longbow "delete", // EcoQuest 1 + "size", // EcoQuest 1 "signal", // EcoQuest 1, GK1 #ifdef ENABLE_SCI32 "newWith", // SCI2 array script @@ -212,6 +213,7 @@ enum ScriptPatcherSelectors { SELECTOR_at, SELECTOR_owner, SELECTOR_delete, + SELECTOR_size, SELECTOR_signal #ifdef ENABLE_SCI32 , @@ -669,10 +671,55 @@ static const uint16 ecoquest1PatchMosaicPuzzleFix[] = { PATCH_END }; +// The column puzzle in room 160 can be put in a state that can't be completed. +// This is a bug in the original that affects all versions. +// +// The puzzle consists of nine columns that must be rotated to their correct +// positions in the correct order. As each column is solved it is locked. When +// leaving the room the puzzle state is saved to globals but this state is +// insufficient to recreate the puzzle. The game saves column positions but not +// lock states. Instead it infers lock states from positions when restoring but +// this is inaccurate because columns can be put in their correct positions out +// of order. If the player leaves the room while all columns are in their +// correct positions but before the puzzle is solved then all columns will be +// locked when returning and the game can't be completed. +// +// The proper solution would be to save and restore lock states but it would be +// impractical to patch in that functionality while retaining save game +// compatibility. Instead we patch the loop that reinitializes lock states to +// skip the last column so that it's always unlocked and the player can't get +// stuck. This code only runs when the puzzle isn't solved and should never +// have been able to lock the last column. +// +// Applies to: All Floppy and CD versions +// Responsible method: Local procedure 5 in script 160 +// Fixes bug #10885 +static const uint16 ecoquest1SignatureColumnPuzzleFix[] = { + 0x39, SIG_SELECTOR8(size), // pushi size + 0x76, // push0 + 0x72, SIG_ADDTOOFFSET(+2), // lofsa columnList [ columns in solution order ] + 0x4a, 0x04, // send 04 [ columnList:size ] + 0x22, // lt? [ temp0 < columnList:size (9) ] + 0x30, SIG_ADDTOOFFSET(+2), // bnt [ end of method ] + 0x39, SIG_MAGICDWORD, // pushi cel + SIG_SELECTOR8(cel), + 0x76, // push0 + 0x39, SIG_SELECTOR8(at), // pushi at + SIG_END +}; + +static const uint16 ecoquest1PatchColumnPuzzleFix[] = { + 0x34, PATCH_UINT16(0x0008), // ldi 0008 [ only initialize 8 of 9 columns ] + 0x32, PATCH_UINT16(0x0002), // jmp 0002 + PATCH_END +}; + + // script, description, signature patch static const SciScriptPatcherEntry ecoquest1Signatures[] = { { true, 140, "CD: mosaic puzzle fix", 2, ecoquest1SignatureMosaicPuzzleFix, ecoquest1PatchMosaicPuzzleFix }, { true, 160, "CD: give superfluous oily shell", 1, ecoquest1SignatureGiveOilyShell, ecoquest1PatchGiveOilyShell }, + { true, 160, "CD/Floppy: column puzzle fix", 1, ecoquest1SignatureColumnPuzzleFix, ecoquest1PatchColumnPuzzleFix }, { true, 660, "CD: bad messagebox and freeze", 1, ecoquest1SignatureStayAndHelp, ecoquest1PatchStayAndHelp }, { true, 816, "CD: prophecy scroll", 1, ecoquest1SignatureProphecyScroll, ecoquest1PatchProphecyScroll }, SCI_SIGNATUREENTRY_TERMINATOR |