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SCI: Fix Timer rollover bugs in KQ5, MOTHERGOOSE256

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This commit is contained in:
sluicebox 2021-03-21 17:32:17 -07:00
parent fbacb5b9e1
commit 294d733d9f
1 changed files with 49 additions and 0 deletions
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49
engines/sci/engine/script_patches.cpp
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@ -620,6 +620,52 @@ static const uint16 ecoquest1Sq4CdNarratorLockupPatch[] = {
PATCH_END
};
// Several SCI Version 1 games use a Timer class that doesn't handle kGetTime
// rollover correctly. When Timer:set60ths is called with a tick value that
// elapses after kGetTime rolls over from 65535 to 0, the timer instantly cues.
// The CD versions of KQ5 and Mixed Up Mother Goose set a timer this way when
// playing speech that can't be skipped. As rollover approaches every 18
// minutes and 12 seconds, these messages can instantly complete and cause
// entire scenes to randomly skip. For example, this can happen in KQ5CD's
// Harpy and Hermit cutscenes.
//
// We fix this by replacing the Timer's tick calculation with the correct logic
// that appears in later versions when set60ths was renamed to setTicks.
//
// Applies to: Games that use Timer:set60ths
// Responsible methods: Timer:doit, SpeakTimer:doit in KQ5CD
static const uint16 sciSignatureTimerRollover[] = {
0x67, SIG_ADDTOOFFSET(+1), // pTos ticksToDo
0x63, SIG_ADDTOOFFSET(+1), // pToa lastTime
0x02, // add
0x36, // push
0x76, // push0
SIG_MAGICDWORD,
0x43, 0x42, 0x00, // callk GetTime 00
0x2a, // ult? [ ticksToDo + lastTime u< kGetTime ]
0x2e, SIG_UINT16(0x0013), // bt 0013
0x67, SIG_ADDTOOFFSET(+1), // pTos lastTime
0x76, // push0
SIG_ADDTOOFFSET(+16),
0x30, // bnt [ cue client if acc == true ]
SIG_END
};
static const uint16 sciPatchTimerRollover[] = {
0x76, // push0
0x43, 0x42, 0x00, // callk GetTime 00
0x36, // push
0x67, PATCH_GETORIGINALBYTE(+1), // pTos ticksToDo
0x63, PATCH_GETORIGINALBYTE(+3), // pToa lastTime
0x02, // add
0x04, // sub
0x36, // push
0x35, 0x00, // ldi 00
0x1e, // gt? [ kGetTime - (ticksToDo + lastTime) > 0 ]
0x33, 0x10, // jmp 10 [ cue client if acc == true ]
PATCH_END
};
// ===========================================================================
// Conquests of Camelot
// At the bazaar in Jerusalem, it's possible to see a girl taking a shower.
@ -4918,10 +4964,12 @@ static const uint16 kq5PatchCrispinIntroSignal[] = {
// script, description, signature patch
static const SciScriptPatcherEntry kq5Signatures[] = {
{ true, 0, "CD: harpy volume change", 1, kq5SignatureCdHarpyVolume, kq5PatchCdHarpyVolume },
{ true, 0, "timer rollover", 1, sciSignatureTimerRollover, sciPatchTimerRollover },
{ false, 109, "Crispin intro signal", 1, kq5SignatureCrispinIntroSignal, kq5PatchCrispinIntroSignal },
{ true, 124, "Multilingual: Ending glitching out", 3, kq5SignatureMultilingualEndingGlitch, kq5PatchMultilingualEndingGlitch },
{ false, 124, "Win: GM Music signal checks", 4, kq5SignatureWinGMSignals, kq5PatchWinGMSignals },
{ true, 200, "CD: witch cage init", 1, kq5SignatureWitchCageInit, kq5PatchWitchCageInit },
{ true, 973, "timer rollover", 1, sciSignatureTimerRollover, sciPatchTimerRollover },
SCI_SIGNATUREENTRY_TERMINATOR
};
@ -9540,6 +9588,7 @@ static const SciScriptPatcherEntry mothergoose256Signatures[] = {
{ true, 0, "save limit dialog (SCI1.1)", 1, mothergoose256SignatureSaveLimit, mothergoose256PatchSaveLimit },
{ true, 994, "save limit dialog (SCI1)", 1, mothergoose256SignatureSaveLimit, mothergoose256PatchSaveLimit },
{ true, 90, "main menu button crash", 1, mothergoose256SignatureMainMenuCrash, mothergoose256PatchMainMenuCrash },
{ true, 999, "timer rollover", 1, sciSignatureTimerRollover, sciPatchTimerRollover },
SCI_SIGNATUREENTRY_TERMINATOR
};