Features

Respawn Point Half-Gridlock a1d895ce79

New QR allows the new respawn points to lock the respawn check to the nearest half-grid (8px) position. This places you slightly further from some unsafe obstacles, and helps in certain edge-cases.
New QR Rerolled Drops Always Roll 'Nothing' 4c4a24dd42

This works alongside the other smart drops qrs to help rebalance dropsets. If set, any drops that would be 'rerolled' always roll 'Nothing' instead, keeping the odds of each drop the same under all circumstances. This allows simply removing drops from the pool when they are unneeded, instead of requiring them to be rerolled into other drops.
Both invincibility-granting magic items can now prevent knockback c1930dfd30

If knockback is prevented, the player can ex. walk over spikes without being stopped / hit back.

Player

Water/pitfall attributes for IFrames and Stun Frames 35da0e1ed7
- Allows customizing InvFrames after falling / drowning
- Allows stunning the player (to prevent them from ex. walking directly back into the water/pitfall) after falling / drowning
Cane of Byrna "Invincible Hero" flag 627087fdba

Implement the Cane of Byrna's "Invincible Hero" flag, which was present in the item editor but had never actually done anything. When set, an active Byrna beam now protects the Hero from damage, the same way Nayru's Love (Divine Protection) does.

Editor

Improve some tile editor shortcuts 54183281b9
- Ctrl+Arrows no longer prevent changing pages
- Holding Shift makes the Alt+Arrows shortcut move in increments of 8px instead of 1px
Improve tile editor quarter-tile draw modes 0607bcd629

"Diag Flip" was implemented wrong, acting exactly the same as 180 rotation- it has been replaced with "+Diag Flip" and "-Diag Flip" which properly flip across the positive and negative diagonal lines respectively.

"Translate" has also been added, drawing at the same position in each of the 4 quarters of the tile, useful for minitile-drawing ex. for life meters.
Show combo label on favorite combo tooltip 4f0513ce28
Item Wizard for Stomp Boots feeb4a9c24
Subscreen 'hint' draws 7d53a5989c

Some things that would normally be invisible will have a 'hint' draw to indicate where and what it is in the editor (ex. Button Items, Text with empty string, etc).

Bug Fixes

AltGr key combinations 6e83d3b488
Ditherblit ignoring clipping rectangles 4518a325c8
Add runtime SSE2/SSSE3 detection and fallbacks f317a33299

2.55.12 added fast-path code for some tile draws, which required CPUs made in at least 2007 or later. Older CPUs would crash when executing these unknown instructions. Now, the tile drawing code checks if the CPU supports these instructions, and if not uses the slower drawing code.
Preserve scroll position in new listers e352f8e7b5 Discord
Switchhook Block combo attributes overlapping 0b38f9e5d4

The 'Item/Dropset' attribute was in the same spot as the 'Break SFX' attribute! The 'Item/Dropset' attribute has been moved to fix this. If you were using 'Item/Dropset' before, you'll want to update your Switchhook Block combos.
Continue hearts being improperly bounded e1c870c9ee

This led to high continue heart values wrapping around to lower values.

Regressed in 2.55-alpha-120 (acb7c84).
Prevent out-of-bounds write when loading a quest with an invalid combo count 722bcf936c

A crafted quest file could declare a combo count larger than the maximum number of combos, causing writes past the end of the combo buffer.
Prevent out-of-bounds write when loading a quest with too many counters e5018aa903

A crafted quest file could declare a counter count larger than the maximum, causing writes past the end of the counter arrays in the init data.
Prevent out-of-bounds read from invalid DMap subscreen script index 9285d6aa74

A crafted quest file could set a DMap's active/passive subscreen script index beyond the script table, causing an out-of-bounds read and dereference of an invalid script pointer when the quest is loaded or run.
Avoid out-of-bounds read on unterminated enemy name in quest file 3bfac596af

A crafted quest file could supply a 64-byte enemy name with no terminator, causing a string length scan to read past the end of the buffer.
Avoid out-of-bounds read from invalid FFC combo index during quest load c61ec35b6f

A crafted quest file could give a freeform combo a combo index past the end of the combo buffer, causing an out-of-bounds read while fixing up old quests.
Avoid out-of-bounds read from legacy secret-combo template index 067feacc4b

Loading a crafted old-format quest could use a secret-combo value as an index past the end of the template screen's combo arrays, reading out of bounds.
Prevent out-of-bounds write from invalid combo pool/autocombo counts dca3afdf21

A crafted quest file could declare more combo pools or autocombos than the engine supports, causing writes past the end of those fixed arrays.
Prevent out-of-bounds write from invalid favorite combo data f115f177cb

A crafted quest file could declare too many favorite combos or an invalid per-row value, causing writes past the favorite-combo arrays (or a divide by zero from a zero per-row value).
QR for chests/signs/lockblocks working above layer 2 d4d23e1264
[mac] size default window using the screen's usable area 4fa90869b0

The default window size on macOS subtracted a hardcoded guess for the menu bar and ignored the dock, so the window could end up larger than the available space. It now uses the screen's actual usable area, which excludes both the menu bar and the dock, and reserves the window title bar at the correct size on high-DPI displays.

Player

Sideview drowning softlocking the player forever sometimes a47f527d64
Hero->Immortal not clearing on quest load be322f1002
Per-quest controls resetting wrongly on Continue e84449c199
Pitfalls not resetting attack timer 015b811e09

this allowed the player to be in the attacking animation instead of the falling animation in some situations.
Ffc solid pushing of the player stopping too soon d9cb3d03a9

incorrect hitbox check was being used
Lens hints showing during player death animation edc8e90f65
Softlock with No Scrolling Screen While Carrying QR in NES dungeons d23376f639

This QR wasn't preventing the "suck" of bombed doors and walk-through walls from trying to scroll. This resulted in softlocking the player because they were being permanently sucked into the scroll, while the scroll was being prevented by the carried object.
Standing state not checking properly for ffc platforms 1677d574a5

this made it hard to jump when riding a downwards-moving ffc platform
Wrong offset being used for solid object pushing ac1e9ed137

These offsets would commonly be the same value, so, unlikely this actually caused any issues yet.
Fix ePatra firing too early when ENEMY_FLAG7 is set 86ad21162c

When the "don't fire while looping" flag was set, ePatra could still fire in certain attack modes (dmisc20==4 and default) regardless of whether it was mid-loop. Now all modes correctly wait until the loop finishes before allowing fire.
New/Newer Hero Movement inconsistencies c4d457feaa

Some spots were only checking for New movement which should've checked for either, causing inconsistencies between enabling both and just enabling newer movement.
Allow "255"/"0xFF" as transparent for more subscreen colors 72b13e7a78

Setting the BS Dark color to 0xFF in misc colors makes its minimap look more similar to Dungeon/Interior minimaps.

Some colors already handled this, but it was missing from places that could really use it.
Sideview drowning sprites being broken 7c22a4bd51
Sideview ground checks ignoring enemies' 'ignore solidity' flag 82b6eb3d3b

The code for "is the enemy standing on a solid" was using entirely different code that didn't check this flag. Now it checks it when "Use 'Scripted Movement' for engine movement" is enabled.
Chests not checking all layers for Armos/Chest->Item 4f1a6d2a66

this caused chests placed on layers > 2 to open without giving you anything
Enemy bombs disappearing due to negative fuse timer d996f1b9ae
Bombs not resetting Timeout when exploding b831914950

Timeout is meant to function as an alternate fuse for these, but if it explodes before the timeout runs out, the timeout was leaking over to the explosion and killing it mid-boom.
Light beams not working properly during stepforward 1413c8f520
Item sounds sometimes being wrongly killed 8bb98f0594

The hookshot resetting code was killing the sound of the currently in-use item, without regard for if that item was a hookshot or not.
Pushblocks not properly counting towards trigger groups 6677d9b6e8
BS Overworld not respecting having the Map item or not 3cacbc2fd1
Enemy bad hitboxes for standing on the ground in sideview 8513081f8a

Enemies with weird hitboxes may still have other problems, such as walking sideways through walls, because enemy movement code is super jank- though the Use 'Scripted Movement' for engine movement enemy movement flag seems to help with those issues.
New respawn points not counting damage combos or slidey ice 88e4644fe4
Solid moving objects interacting poorly with water/pits bf4281c74f

they now can push the player into pits, and no longer push the player while the player is already falling/drowning
Prevent infinite loop in trig_trigger_groups bc0054ef5b
Combo general loop sfx cutting out when looping ec0e1a1268
Knockback through sideview platforms 147c1b0413
Buggy solid platform sideview ffc collision c51805f07a

When moving at angles the collision for riding the platform was getting confused with the collision for solid objects pushing the player, knocking the player off the platform weirdly.
Shooter/crumble combos ticking when screen is 'frozen' d6c4678934
Prevent rng desync when manually ending replay 8f20d39267

When playing a replay file, selecting Quit in the menu caused an rng desync dialog to appear. Now, the program actually closes.
Deterministic high-precision math for gameplay and replays c44d4ff325
While recording a replay, trig (Sin/Cos/Tan) switched to a low-precision lookup table, so simply having a replay enabled could change gameplay. Separately, ArcSin/ArcCos/ArcTan and Ln/Log10/Pow always used the system math library, whose results vary across platforms and compilers - a source of cross-platform replay desyncs. All of this math is now both high-precision and bit-identical on every platform and compiler: recording a replay never changes behavior, and replays cannot desync across machines due to math differences.

As an example of how the old trig error presented: in Stellar Seas, a boss laser derives its collision geometry from trig, and the recording- mode error (up to ~0.001) was amplified by the script into "phantom hitboxes" - hits landing tens of pixels away from the visible attack, only while a replay was recording.

Other user-facing effects:
- Pow(2, n) and Pow(10, n) are exact, and Log10 of a power of ten returns an exact integer, so digit-counting scripts behave reliably.
- Replays recorded before this version still play back with the old math, bit for bit.
Walking/standing combo effects not blocked by bridges c374637443

this includes the general tab sfx/sprites
Stomp Boots block flags being backwards 68ef97426d

Regressed in 2.55.0 (de1cb2b).
Frozen scripts wrongly having draws stopped by running strings 98b0be2340
SCC setting screen state of non-current screen using wrong map 94b4872336
Bottom 8px bad collision using 4-way newer hero movement d9faad3742
Stop triforce pickup softlocking with low MP/HP counter settings 8d1181cdfc

Picking up a triforce would freeze the game when MP per Block was set to 1-3 (or HP per Heart to 1). The refill animation never finished, so the pickup cutscene looped forever and quitting crashed.
1-wide gaps being hard to fall through in sideview c542da8ebe
Handle replay load failures gracefully with a GUI error 90ddfd3d7f

Loading an invalid replay could crash the program. Now, an error dialog is displayed when a replay fails to load.
Prevent previous qst misc data leaking to next 527c9699cc
Hammer triggering combos outside its hitbox 67dc1df14c

The hammer could trigger combos and secret flags above and behind the player, outside the area its hitbox was drawn. It was most obvious with the "don't trigger while the hammer is in the air" item flag enabled: on the first frame the hammer became active on the ground, it triggered combos where it had been a frame earlier, while still raised.
Armos combos with custom enemies not clearing the combo 564fa7fb21
Large armos bad tile offset 9f8a9714b5
Auto Sidewarp combos not using the assigned Warp SFX 70ab4774ae

Editor

Remove unused wand attributes/flags from item editor 14ede02c46
Tile editor rotations sometimes undone a1d15cc88b Discord

Caused by a bug in tile caching code.
Preview mode combo cycling using bad colors for Ignore CSet 13636edb06
Water/shallow water combo wizard not setting levels properly fec4002703

If you didn't edit the Req Item Level/Flippers Level fields, they would stay at value 0, despite showing as value 1 in the GUI. For req item level, this could completely disable the passive hp mod.
Don't show confirmation on exit in new quest wizard 29f7dfedc0
'block' missing from 'Mirror (Custom)' attribute help bf5cfa1d1c
Typo in ffc editor 'Swap' flags' info 4e705ed824
Avoid potential crash when drawing doors 1c850ea5d7
Clean up the string editor / add infobuttons 80aae94aaf
Respect "New Darkness Trans Layer Stacking" QR in editor 13f5c6b760
Clean up 'Button Counter' subscreen widget '?' buttons fe9053d1e4

ZScript Standard Library (std.zh)

CenterY for an item returned an X-based coordinate 162013f324

CenterY(item, false) used the item's X coordinate instead of its Y in the sprite-center branch, returning a wrong value. It now uses Y, matching the hitbox branch and every other CenterY overload.

ZScript

Show correct code location for script drawing errors 6fdd14f83e
Prevent DMap and hero scripts running twice on init 8285221f7e Discord
The first frame of these scripts were incorrectly running twice. The exact behavior depended on whether these QRs are enabled:
- "Scripts Draw During Warps"
- "Passive Subscreen Script runs during wipes/refills"
This bug only occurred if one of these QRs was enabled.
Prevent crash from out-of-bounds sprite script IDs 9202045134
Use proper gfx for script created sword beams 559bdddf2a

This regressed in 9ca67c7b0 (2.55-alpha-120).
Game->CurrentItemID() using a bad default value for bitflags fca4d972d0
Strcmp-family functions now always return -1, 0, or 1 6d55503949

strcmp(), stricmp(), strncmp(), and strnicmp() returned the raw C library comparison result, which is only guaranteed to be negative, zero, or positive - the exact value varies by platform and compiler. Scripts comparing the result against exactly -1 or 1 could behave differently across builds. These functions now always return -1, 0, or 1.
Free script-owned objects when a script's state is cleared 201ebe3426

Resetting or clearing a script's engine data did not reliably release the script objects that the script had taken ownership of. Several script types that run in less common ways (like active subscreen scripts) could therefore leak these until the engine eventually ran out of slots.

Releasing owned objects is now an inseparable part of resetting or clearing a script's engine data, so it can no longer be skipped.
Prevent crash when taking the modulo of the minimum integer by -1 3f09fc4fa2

Computing the remainder of the smallest representable integer modulo -1 crashed the game, in both the interpreter and the JIT. The result is now 0, the same as any value modulo -1.
Remove unimplemented Audio->PauseCurMIDI() and ResumeCurMIDI() ff942cc537
Free objects owned by DMap and subscreen scripts 97ac507bf8

Objects and arrays that a DMap, OnMap, or active/passive subscreen script took ownership of were not released when the script's state was cleared, leaking them until the engine ran out of object slots.

ZConsole

[win] prevent debug console from freezing bd68efde70 Discord

The named-pipe connection was treated as a hard failure when it didn't complete instantly, popping a modal dialog that could hide behind the game window (appearing as a frozen black screen) and orphaning the helper console in an endless retry loop. Connect now waits with a bounded timeout so a slow-to-start console attaches normally, and any setup failure quietly disables the console instead of blocking the app.

Refactors

Player

Copy cpos_update optimization from combos to ffcs 07f75a7887
Greatly speed up refresh_rgb_tables using last key cache 809dd2019b Discord

This greatly speeds up the program within fade effects. For terror_of_necromancy_demo6_32_of_54.zplay it reduced the total CPU time being spent in refresh_rgb_tables from 60% to 0.3%.
Optimize code for common dithering args af60e181aa

This speeds up dithering by a lot - between 3x and 25x depending on the platform.
[win] remove obsolete vsync workaround (use_dwm_flush) 8d33ad6b05

Remove a Windows-only screen-tearing workaround from the Vista/Win7 era, along with its hidden use_dwm_flush config option, which is now ignored if set. It was off by default and is redundant now: the display backend owns frame presentation, and desktop composition is always on in modern Windows.
Greatly speed up dithercircfill d50e8a9da3 Discord

Editor

Improve FFC hover tooltips 78d9fc3d32

CI

Upgrade actions due to node 20 deprecation d64d2270dc

Misc.

Update rulesets f6b7cbcd56

Editor

Remove darkness dithered corner by default a8b25517b2

Etc->Options->Toggles->Show Darkness Corner Dither toggles this Darkness now shows a line in Screen Info, to less obtrusively indicate dark screens.
Improve infotext for string editor 'Layer' bc2ef07408