libretro/scummvm
1
0
Fork 0
mirror of https://github.com/libretro/scummvm.git synced 2025-04-12 19:58:29 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

SCI: Cleanup QFG2 patches

Browse Source
This commit is contained in:
Vhati 2019-01-19 01:25:17 -05:00 committed by Filippos Karapetis
parent fbd1181300
commit f339402fe6
1 changed files with 41 additions and 40 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

81
engines/sci/engine/script_patches.cpp
View File

@ -7423,72 +7423,73 @@ static const SciScriptPatcherEntry qfg1vgaSignatures[] = {
// ===========================================================================
// This is a very complicated bug.
// When the player encounters an enemy in the desert while riding a saurus and later
// tries to get back on it by entering "ride", the game will not give control back
// to the player.
// When the player encounters an enemy in the desert while riding a saurus and
// later tries to get back on it by entering "ride", the game will not give
// control back to the player.
//
// This is caused by script mountSaurus getting triggered twice.
// Once by entering the command "ride" and then a second time by a proximity check.
// This is caused by script mountSaurus getting triggered twice. Once by
// entering the command "ride" and then a second time by a proximity check.
//
// Both are calling mountSaurus::init() in script 20, this one disables controls
// then mountSaurus::changeState() from script 660 is triggered
// mountSaurus::changeState(5) finally calls mountSaurus::dispose(), which is also in script 20
// which finally re-enables controls
// Both are calling mountSaurus::init() in script 20. This one disables
// controls. Then mountSaurus::changeState() from script 660 is triggered.
// Finally, mountSaurus::changeState(5) calls mountSaurus::dispose(), also in
// script 20, which re-enables controls.
//
// A fix is difficult to implement. The code in script 20 is generic and used by multiple objects
// A fix is difficult to implement. The code in script 20 is generic and used
// by multiple objects
//
// Originally I decided to change the responsible globals (66h and A1h) during mountSaurus::changeState(5).
// This worked as far as for controls, but mountSaurus::init changes a few selectors of ego as well, which
// won't get restored in that situation, which then messes up room changes and other things.
// An early attempt changed the responsible vars (global[102], global[161])
// during mountSaurus::changeState(5). This worked for controls, but
// mountSaurus::init changes a few selectors of ego as well, which won't get
// restored in that situation, which then messes up room changes and other
// things.
//
// I have now decided to change sheepScript::changeState(2) in script 665 instead.
// Instead we change sheepScript::changeState(2) in script 665.
//
// This fix could cause issues in case there is a cutscene, where ego is supposed to get onto the saurus using
// sheepScript.
// Note: This could cause issues in case there is a cutscene, where ego is
// supposed to get onto the saurus using sheepScript.
//
// Applies to at least: English PC Floppy, English Amiga Floppy
// Responsible method: mountSaurus::changeState(), mountSaurus::init(), mountSaurus::dispose()
// Fixes bug: #5156
static const uint16 qfg2SignatureSaurusFreeze[] = {
0x3c, // dup
0x35, 0x02, // ldi 5
0x35, 0x02, // ldi 2
SIG_MAGICDWORD,
0x1a, // eq?
0x30, SIG_UINT16(0x0043), // bnt [ret]
0x76, // push0
SIG_ADDTOOFFSET(+61), // skip to dispose code
0x39, SIG_SELECTOR8(dispose), // pushi "dispose"
0x39, SIG_SELECTOR8(dispose), // pushi dispose
0x76, // push0
0x54, 0x04, // self 04
SIG_END
};
static const uint16 qfg2PatchSaurusFreeze[] = {
0x81, 0x66, // lag 66h
0x2e, SIG_UINT16(0x0040), // bt [to dispose code]
0x81, 0x66, // lag global[66h]
0x2e, PATCH_UINT16(0x0040), // bt [to dispose code]
0x35, 0x00, // ldi 0 (waste 2 bytes)
PATCH_END
};
// The Jackalmen combat code has at least one serious issue.
//
// Jackalmen may attack in groups.
// This is handled by 2 globals.
// Global 136h contains the amount of cur. Jackalmen alive.
// Global 137h contains the amount of cur. Jackalmen killed during combat.
// Jackalmen may attack in groups. This is handled by 2 globals.
// global[136h]: amount of Jackalmen still alive.
// global[137h]: amount of Jackalmen killed so far during combat.
//
// Global 137h is subtracted from Global 136h after combat
// has ended, BUT when the player manages to hit the last enemy
// AFTER defeating it during its death animation (yes, that is possible - don't ask),
// the code is called a second time. Subtracting 137h twice, which will make global 136h
// negative and which will then make it so that there is an inconsistent state.
// Some variables will show that there is still an enemy, while others don't.
// After combat has ended, global[137h] is subtracted from global[136h]. BUT
// when the player manages to hit the last enemy AFTER defeating it during its
// death animation (yes, that is possible - don't ask), the code is called a
// second time. Subtracting global[137h] twice, which will make global[136h]
// negative and will then create an inconsistent state. Some variables will
// show that there is still an enemy, while others don't. The game will crash
// when leaving the room. The original interpreter would show the infamous
// "Oops, you did something we weren't expecting..."
//
// Which will then make the game crash when leaving the current room.
// The original interpreter would show the infamous "Oops, you did something we weren't expecting...".
//
// Applies to at least: English Floppy (1.102+1.105)
// TODO: Check, if patch works for 1.000. That version surely has the same bug.
// Applies to at least: English Floppy (1.102+1.105)
// Responsible method: jackalMan::die (script 695)
// Fixes bug: #10218
static const uint16 qfg2SignatureOopsJackalMen[] = {
@ -7511,11 +7512,11 @@ static const uint16 qfg2SignatureOopsJackalMen[] = {
static const uint16 qfg2PatchOopsJackalMen[] = {
0x80, PATCH_UINT16(0x0136), // lag global[136h]
0x31, 0x0E, // bnt [skip everything] - requires 5 extra bytes
0x31, 0x0e, // bnt [skip everything] - requires 5 extra bytes
0x8b, 0x00, // lsl local[0]
0x35, 0x00, // ldi 0
0x22, // lt?
0x31, 0x08, // bnt [Jackalman death animation code] - save 1 byte
0x31, 0x08, // bnt [Jackalman death animation code] (save 1 byte)
0x38, PATCH_GETORIGINALUINT16(+9), // pushi (die)
0x76, // push0
0x57, 0x66, 0x04, // super Monster, 4
@ -7523,7 +7524,7 @@ static const uint16 qfg2PatchOopsJackalMen[] = {
// Jackalman death animation code
0x83, 0x00, // lal local[0]
0x18, // not
0x31, 0x03, // bnt [make next enemy walk in] - save 1 byte
0x31, 0x03, // bnt [make next enemy walk in] (save 1 byte)
PATCH_END
};
@ -7546,7 +7547,7 @@ static const uint16 qfg2SignatureImportDialog[] = {
0x7a, // push2
0x39, 0x03, // pushi 03
0x36, // push
0x43, 0x72, 0x04, // callk Memory 4
0x43, 0x72, 0x04, // callk Memory, 4
0x35, 0x00, // ldi 00
0x65, 0x20, // aTop text
SIG_END
@ -7595,9 +7596,9 @@ static const uint16 qfg2PatchImportCharType[] = {
0x35, 0x04, // ldi 04
0x08, // div
0x36, // push
0xa8, SIG_UINT16(0x0248), // ssg global[0248h] <-- patched to save 2 bytes
0xa8, PATCH_UINT16(0x0248), // ssg global[0248h] <-- patched to save 2 bytes
0x8b, 0x1f, // lsl local[1Fh]
0xa8, SIG_UINT16(0x0155), // ssg global[0155h] <-- patched to save 2 bytes
0xa8, PATCH_UINT16(0x0155), // ssg global[0155h] <-- patched to save 2 bytes
// new code, directly from the official sierra patch file
0x83, 0x01, // lal local[01h]
0xa1, 0xbb, // sag global[BBh]