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Diffstat (limited to 'docs')
| -rw-r--r-- | docs/bugs_and_glitches.md | 311 |
1 files changed, 287 insertions, 24 deletions
diff --git a/docs/bugs_and_glitches.md b/docs/bugs_and_glitches.md index f4f6a6159..7a7d80250 100644 --- a/docs/bugs_and_glitches.md +++ b/docs/bugs_and_glitches.md @@ -15,13 +15,16 @@ Some fixes are mentioned as breaking compatibility with link battles. This can b ## Contents +- [Perish Song and Spikes can leave a Pokémon with 0 HP and not faint](#perish-song-and-spikes-can-leave-a-pokémon-with-0-hp-and-not-faint) - [Thick Club and Light Ball can make (Special) Attack wrap around above 1024](#thick-club-and-light-ball-can-make-special-attack-wrap-around-above-1024) - [Metal Powder can increase damage taken with boosted (Special) Defense](#metal-powder-can-increase-damage-taken-with-boosted-special-defense) - [Reflect and Light Screen can make (Special) Defense wrap around above 1024](#reflect-and-light-screen-can-make-special-defense-wrap-around-above-1024) - [Glacier Badge may not boost Special Defense depending on the value of Special Attack](#glacier-badge-may-not-boost-special-defense-depending-on-the-value-of-special-attack) - [Moves with a 100% secondary effect chance will not trigger it in 1/256 uses](#moves-with-a-100-secondary-effect-chance-will-not-trigger-it-in-1256-uses) - [Belly Drum sharply boosts Attack even with under 50% HP](#belly-drum-sharply-boosts-attack-even-with-under-50-hp) +- [Berserk Gene's confusion lasts for 256 turns or the previous Pokémon's confusion count](#berserk-genes-confusion-lasts-for-256-turns-or-the-previous-Pokémons-confusion-count) - [Confusion damage is affected by type-boosting items and Explosion/Self-Destruct doubling](#confusion-damage-is-affected-by-type-boosting-items-and-explosionself-destruct-doubling) +- [Saves corrupted by mid-save shutoff are not handled](#saves-corrupted-by-mid-save-shutoff-are-not-handled) - [Moves that lower Defense can do so after breaking a Substitute](#moves-that-lower-defense-can-do-so-after-breaking-a-substitute) - [Counter and Mirror Coat still work if the opponent uses an item](#counter-and-mirror-coat-still-work-if-the-opponent-uses-an-item) - [A Disabled but PP Up–enhanced move may not trigger Struggle](#a-disabled-but-pp-upenhanced-move-may-not-trigger-struggle) @@ -32,9 +35,11 @@ Some fixes are mentioned as breaking compatibility with link battles. This can b - [Beat Up may fail to raise Substitute](#beat-up-may-fail-to-raise-substitute) - [Beat Up may trigger King's Rock even if it failed](#beat-up-may-trigger-kings-rock-even-if-it-failed) - [Present damage is incorrect in link battles](#present-damage-is-incorrect-in-link-battles) +- [A Transformed Pokémon can use Sketch and learn otherwise unobtainable moves](#a-transformed-pokémon-can-use-sketch-and-learn-otherwise-unobtainable-moves) - ["Smart" AI encourages Mean Look if its own Pokémon is badly poisoned](#smart-ai-encourages-mean-look-if-its-own-pokémon-is-badly-poisoned) - [AI makes a false assumption about `CheckTypeMatchup`](#ai-makes-a-false-assumption-about-checktypematchup) - [NPC use of Full Heal or Full Restore does not cure Nightmare status](#npc-use-of-full-heal-or-full-restore-does-not-cure-nightmare-status) +- [NPC use of Full Heal does not cure confusion status](#npc-use-of-full-heal-does-not-cure-confusion-status) - [HP bar animation is slow for high HP](#hp-bar-animation-is-slow-for-high-hp) - [HP bar animation off-by-one error for low HP](#hp-bar-animation-off-by-one-error-for-low-hp) - [Experience underflow for level 1 Pokémon with Medium-Slow growth rate](#experience-underflow-for-level-1-pokémon-with-medium-slow-growth-rate) @@ -75,6 +80,54 @@ Some fixes are mentioned as breaking compatibility with link battles. This can b - [`BattleAnimCmd_ClearObjs` only clears the first 6⅔ objects](#battleanimcmd_clearobjs-only-clears-the-first-6-objects) +## Perish Song and Spikes can leave a Pokémon with 0 HP and not faint + +*Fixing this bug will break compatibility with standard Pokémon Crystal for link battles.* + +([Video](https://www.youtube.com/watch?v=1IiPWw5fMf8&t=85)) + +**Fix:** Edit `CheckFaint_PlayerThenEnemy` and `CheckFaint_EnemyThenPlayer` in [engine/battle/core.asm](https://github.com/pret/pokecrystal/blob/master/engine/battle/core.asm): + +```diff + jp HandleEncore + ++HasAnyoneFainted: ++ call HasPlayerFainted ++ call nz, HasEnemyFainted ++ ret ++ + CheckFaint_PlayerThenEnemy: ++.faint_loop ++ call .Function ++ ret c ++ call HasAnyoneFainted ++ ret nz ++ jr .faint_loop ++ ++.Function: + call HasPlayerFainted + jr nz, .PlayerNotFainted + call HandlePlayerMonFaint + ... +``` + +```diff + CheckFaint_EnemyThenPlayer: ++.faint_loop ++ call .Function ++ ret c ++ call HasAnyoneFainted ++ ret nz ++ jr .faint_loop ++ ++.Function: + call HasEnemyFainted + jr nz, .EnemyNotFainted + call HandleEnemyMonFaint + ... +``` + + ## Thick Club and Light Ball can make (Special) Attack wrap around above 1024 *Fixing this bug will break compatibility with standard Pokémon Crystal for link battles.* @@ -271,6 +324,39 @@ As Pryce's dialog ("That BADGE will raise the SPECIAL stats of POKéMON.") impli ``` +## Berserk Gene's confusion lasts for 256 turns or the previous Pokémon's confusion count + +*Fixing this bug will break compatibility with standard Pokémon Crystal for link battles.* + +([Video](https://youtube.com/watch?v=Pru3mohq20A)) + +**Fix:** Edit `HandleBerserkGene` in [engine/battle/core.asm](https://github.com/pret/pokecrystal/blob/master/engine/battle/core.asm): + +```diff + HandleBerserkGene: + ... + ld a, BATTLE_VARS_SUBSTATUS3 + call GetBattleVarAddr + push af + set SUBSTATUS_CONFUSED, [hl] ++ ld a, [hBattleTurn] ++ and a ++ ld hl, wEnemyConfuseCount ++ jr z, .set_confuse_count ++ ld hl, wPlayerConfuseCount ++.set_confuse_count ++ call BattleRandom ++ and %11 ++ add a, 2 ++ ld [hl], a + ld a, BATTLE_VARS_MOVE_ANIM + call GetBattleVarAddr + ... +``` + +This makes the Berserk Gene use the regular confusion duration (2-5 turns). + + ## Confusion damage is affected by type-boosting items and Explosion/Self-Destruct doubling *Fixing this bug will break compatibility with standard Pokémon Crystal for link battles.* @@ -279,11 +365,15 @@ As Pryce's dialog ("That BADGE will raise the SPECIAL stats of POKéMON.") impli **Fix:** -First, edit [hram.asm](https://github.com/pret/pokecrystal/blob/master/hram.asm): +First, edit [wram.asm](https://github.com/pret/pokecrystal/blob/master/wram.asm): ```diff - hClockResetTrigger:: db ; ffeb -+hIsConfusionDamage:: db ; ffec + wTurnEnded:: db ; c6b4 + +- ds 1 ++wIsConfusionDamage:: db ; c6b5 + + wPlayerStats:: ; c6b6 ``` Then edit four routines in [engine/battle/effect_commands.asm](https://github.com/pret/pokecrystal/blob/master/engine/battle/effect_commands.asm): @@ -296,7 +386,7 @@ Then edit four routines in [engine/battle/effect_commands.asm](https://github.co pop af ld e, a + ld a, TRUE -+ ldh [hIsConfusionDamage], a ++ ld [wIsConfusionDamage], a ret ``` @@ -306,7 +396,7 @@ Then edit four routines in [engine/battle/effect_commands.asm](https://github.co ... .skip_zero_damage_check + xor a ; Not confusion damage -+ ldh [hIsConfusionDamage], a ++ ld [wIsConfusionDamage], a + ; fallthrough + +ConfusionDamageCalc: @@ -322,7 +412,7 @@ Then edit four routines in [engine/battle/effect_commands.asm](https://github.co ; Item boosts + +; Item boosts don't apply to confusion damage -+ ldh a, [hIsConfusionDamage] ++ ld a, [wIsConfusionDamage] + and a + jr nz, .DoneItem + @@ -361,6 +451,109 @@ Then edit four routines in [engine/battle/effect_commands.asm](https://github.co ``` +## Saves corrupted by mid-save shutoff are not handled + +([Video 1](https://www.youtube.com/watch?v=ukqtK0l6bu0), [Video 2](https://www.youtube.com/watch?v=c2zHd1BPtvc)) + +**Fix:** Edit `MoveMonWOMail_InsertMon_SaveGame` and `_SaveGameData` in [engine/menus/save.asm](https://github.com/pret/pokecrystal/blob/master/engine/menus/save.asm): + +```diff + MoveMonWOMail_InsertMon_SaveGame: + ... + ld a, TRUE + ld [wSaveFileExists], a + farcall StageRTCTimeForSave + farcall BackupMysteryGift +- call ValidateSave ++ call InvalidateSave + call SaveOptions + call SavePlayerData + call SavePokemonData + call SaveChecksum +- call ValidateBackupSave ++ call ValidateSave ++ call InvalidateBackupSave + call SaveBackupOptions + call SaveBackupPlayerData + call SaveBackupPokemonData + call SaveBackupChecksum ++ call ValidateBackupSave + farcall BackupPartyMonMail + farcall BackupMobileEventIndex + farcall SaveRTC + ... +``` + +```diff + _SaveGameData: + ... + ld a, TRUE + ld [wSaveFileExists], a + farcall StageRTCTimeForSave + farcall BackupMysteryGift +- call ValidateSave ++ call InvalidateSave + call SaveOptions + call SavePlayerData + call SavePokemonData + call SaveBox + call SaveChecksum +- call ValidateBackupSave ++ call ValidateSave ++ call InvalidateBackupSave + call SaveBackupOptions + call SaveBackupPlayerData + call SaveBackupPokemonData + call SaveBackupChecksum ++ call ValidateBackupSave + call UpdateStackTop + farcall BackupPartyMonMail + farcall BackupMobileEventIndex + farcall SaveRTC + ... +``` + +Then create two new routines, `InvalidateSave` and `InvalidateBackupSave`: + +```diff + ValidateSave: + ld a, BANK(sCheckValue1) ; aka BANK(sCheckValue2) + call GetSRAMBank + ld a, SAVE_CHECK_VALUE_1 + ld [sCheckValue1], a + ld a, SAVE_CHECK_VALUE_2 + ld [sCheckValue2], a + jp CloseSRAM + ++InvalidateSave: ++ ld a, BANK(sCheckValue1) ; aka BANK(sCheckValue2) ++ call GetSRAMBank ++ xor a ++ ld [sCheckValue1], a ++ ld [sCheckValue2], a ++ jp CloseSRAM +``` + +```diff + ValidateBackupSave: + ld a, BANK(sBackupCheckValue1) ; aka BANK(sBackupCheckValue2) + call GetSRAMBank + ld a, SAVE_CHECK_VALUE_1 + ld [sBackupCheckValue1], a + ld a, SAVE_CHECK_VALUE_2 + ld [sBackupCheckValue2], a + jp CloseSRAM + ++InvalidateBackupSave: ++ ld a, BANK(sBackupCheckValue1) ; aka BANK(sBackupCheckValue2) ++ call GetSRAMBank ++ xor a ++ ld [sBackupCheckValue1], a ++ ld [sBackupCheckValue2], a ++ jp CloseSRAM +``` + + ## Moves that lower Defense can do so after breaking a Substitute *Fixing this bug will break compatibility with standard Pokémon Crystal for link battles.* @@ -644,6 +837,23 @@ This bug existed for all battles in Gold and Silver, and was only fixed for sing ``` +## A Transformed Pokémon can use Sketch and learn otherwise unobtainable moves + +([Video](https://www.youtube.com/watch?v=AFiBxAOkCGI)) + +**Fix:** Edit `BattleCommand_Sketch` in [engine/battle/move_effects/sketch.asm](https://github.com/pret/pokecrystal/blob/master/engine/battle/move_effects/sketch.asm): + +```diff +-; If the opponent is transformed, fail. ++; If the user is transformed, fail. +- ld a, BATTLE_VARS_SUBSTATUS5_OPP ++ ld a, BATTLE_VARS_SUBSTATUS5 + call GetBattleVarAddr + bit SUBSTATUS_TRANSFORMED, [hl] + jp nz, .fail +``` + + ## "Smart" AI encourages Mean Look if its own Pokémon is badly poisoned ([Video](https://www.youtube.com/watch?v=cygMO-zHTls)) @@ -670,12 +880,8 @@ This bug existed for all battles in Gold and Silver, and was only fixed for sing ld hl, wEnemyMonType1 ldh a, [hBattleTurn] and a -- jr z, CheckTypeMatchup -+ jr z, .get_type + jr z, CheckTypeMatchup ld hl, wBattleMonType1 -+.get_type -+ ld a, BATTLE_VARS_MOVE_TYPE -+ call GetBattleVar ; preserves hl, de, and bc CheckTypeMatchup: -; There is an incorrect assumption about this function made in the AI related code: when -; the AI calls CheckTypeMatchup (not BattleCheckTypeMatchup), it assumes that placing the @@ -683,6 +889,8 @@ This bug existed for all battles in Gold and Silver, and was only fixed for sing -; this assumption is incorrect. A simple fix would be to load the move type for the -; current move into a in BattleCheckTypeMatchup, before falling through, which is -; consistent with how the rest of the code assumes this code works like. ++ ld a, BATTLE_VARS_MOVE_TYPE ++ call GetBattleVar ; preserves hl, de, and bc push hl push de push bc @@ -708,12 +916,67 @@ This bug existed for all battles in Gold and Silver, and was only fixed for sing xor a ld [hl], a ld [wEnemyMonStatus], a -- ; Bug: this should reset SUBSTATUS_NIGHTMARE too -- ; Uncomment the lines below to fix +- ; Bug: this should reset SUBSTATUS_NIGHTMARE +- ; Uncomment the 2 lines below to fix - ; ld hl, wEnemySubStatus1 - ; res SUBSTATUS_NIGHTMARE, [hl] + ld hl, wEnemySubStatus1 + res SUBSTATUS_NIGHTMARE, [hl] + ; Bug: this should reset SUBSTATUS_CONFUSED + ; Uncomment the 2 lines below to fix + ; ld hl, wEnemySubStatus3 + ; res SUBSTATUS_CONFUSED, [hl] + ld hl, wEnemySubStatus5 + res SUBSTATUS_TOXIC, [hl] + ret +``` + + +## NPC use of Full Heal does not cure confusion status + +**Fix:** Edit `EnemyUsedFullRestore`, `EnemyUsedFullHeal`, and `AI_HealStatus` in [engine/battle/ai/items.asm](https://github.com/pret/pokecrystal/blob/master/engine/battle/ai/items.asm): + +```diff + EnemyUsedFullRestore: + call AI_HealStatus + ld a, FULL_RESTORE + ld [wCurEnemyItem], a +- ld hl, wEnemySubStatus3 +- res SUBSTATUS_CONFUSED, [hl] + xor a + ld [wEnemyConfuseCount], a +``` + +```diff + EnemyUsedFullHeal: + call AIUsedItemSound + call AI_HealStatus + ld a, FULL_HEAL ++ ld [wCurEnemyItem], a ++ xor a ++ ld [wEnemyConfuseCount], a + jp PrintText_UsedItemOn_AND_AIUpdateHUD +``` + +```diff + AI_HealStatus: + ld a, [wCurOTMon] + ld hl, wOTPartyMon1Status + ld bc, PARTYMON_STRUCT_LENGTH + call AddNTimes + xor a + ld [hl], a + ld [wEnemyMonStatus], a + ; Bug: this should reset SUBSTATUS_NIGHTMARE + ; Uncomment the 2 lines below to fix + ; ld hl, wEnemySubStatus1 + ; res SUBSTATUS_NIGHTMARE, [hl] +- ; Bug: this should reset SUBSTATUS_CONFUSED +- ; Uncomment the 2 lines below to fix +- ; ld hl, wEnemySubStatus3 +- ; res SUBSTATUS_CONFUSED, [hl] ++ ld hl, wEnemySubStatus3 ++ res SUBSTATUS_CONFUSED, [hl] ld hl, wEnemySubStatus5 res SUBSTATUS_TOXIC, [hl] ret @@ -811,10 +1074,10 @@ This can bring Pokémon straight from level 1 to 100 by gaining just a few exper ([Video](https://www.youtube.com/watch?v=o54VjpAEoO8)) -**Fix:** Edit `_ABoostedStringBuffer2ExpPointsText` and `_StringBuffer2ExpPointsText` in [data/text/common_2.asm](https://github.com/pret/pokecrystal/blob/master/data/text/common_2.asm): +**Fix:** Edit `_BoostedExpPointsText` and `_ExpPointsText` in [data/text/common_2.asm](https://github.com/pret/pokecrystal/blob/master/data/text/common_2.asm): ```diff - _ABoostedStringBuffer2ExpPointsText:: + _BoostedExpPointsText:: text_start line "a boosted" cont "@" @@ -823,7 +1086,7 @@ This can bring Pokémon straight from level 1 to 100 by gaining just a few exper text " EXP. Points!" prompt - _StringBuffer2ExpPointsText:: + _ExpPointsText:: text_start line "@" - text_decimal wStringBuffer2, 2, 4 @@ -1067,7 +1330,7 @@ CopyPokemonName_Buffer1_Buffer3: jr nc, .GenerateDVs ``` -**Better fix:** Rewrite the whole system to use millimeters instead of feet and inches, since they have better precision (1 in = 25.4 mm); and only convert from metric to imperial units for display purposes (or don't, of course). +**Better fix:** Rewrite the whole system to use millimeters instead of feet and inches, since they have better precision (1 in = 25.4 mm); and only convert from metric to imperial units for display purposes (or don't, of course). ## Magikarp lengths can be miscalculated @@ -1264,7 +1527,7 @@ Finally, edit [engine/battle/read_trainer_party.asm](https://github.com/pret/pok ([Video](https://www.youtube.com/watch?v=ojq3xqfRF6I)) -**Fix:** Edit `Slots_PayoutAnim` in [engine/games/slot_machine.asm](https://github.com/pret/pokecrystal/blob/master/engine/games/slot_machine.asm): +**Fix:** Edit `SlotsAction_PayoutAnim` in [engine/games/slot_machine.asm](https://github.com/pret/pokecrystal/blob/master/engine/games/slot_machine.asm): ```diff .okay @@ -1414,7 +1677,7 @@ If you want to make sure `hInMenu` always has a defined value in the move select ... jp .loop - + .quit + pop af + ldh [hInMenu], a @@ -1473,12 +1736,12 @@ First, edit `UsedSurfScript` in [engine/events/overworld.asm](https://github.com writetext UsedSurfText ; "used SURF!" waitbutton closetext - + callasm .empty_fn ; empty function - + readmem wBuffer2 writevar VAR_MOVEMENT - + special ReplaceKrisSprite special PlayMapMusic -; step into the water (slow_step DIR, step_end) @@ -1815,8 +2078,9 @@ This supports up to six entries. ld de, 3 ld hl, .pointers call IsInArray - jr nc, .nope +- jr nc, .nope pop bc ++ jr nc, .nope inc hl ld a, [hli] @@ -1826,7 +2090,6 @@ This supports up to six entries. .nope - ; pop bc -+ pop bc xor a ret ``` |