Library Candidates

Library candidates

Policy: where a maintained NeoForge 1.21.1 library already solves something the layer re-implements, depend on the library (like Baubles -> Curios, Waila -> Jade, NEI -> JEI; see Bridges). This page is a survey (Modrinth API, filter versions:1.21.1 + categories:neoforge, 2026-10-31) of the layer's use cases and what could replace the hand-rolled code. Downloads and dates come from Modrinth. Check a licence and the nesting rules before bundling anything; "bundle" means jar-in-jar like Pehkui and the Scala libraries in build.gradle.

Adopted

Use case	Hand-rolled before	Library	Decision
Entity and player size (Entity.setSize, eyeHeight, Fisk's Heroes shrink/grow)	EntitySizes1710 side table + LivingEntityDimensionsMixin + client pose-stack scale hook	Pehkui 3.8.3+1.21-neoforge, MIT, 10.8 M downloads, last build 2024-06	Adopted, bundled jar-in-jar (no install step; a separately installed newer Pehkui wins). EntitySizes1710 maps sizes to HITBOX_WIDTH/HEIGHT, MODEL_WIDTH/HEIGHT, EYE_HEIGHT; poses (sneak, swim) stay proportional. Risk: no release since 2024, but it still works on NeoForge 21.1.258

Candidates per use case

Use case	What we hand-roll today	Candidate (Modrinth slug)	1.21.1 NeoForge version, licence, downloads, state	Recommendation
Player/entity pose animation (ModelBiped rotation hooks, first-person arm pose, client/FirstPersonPose, Fisk animations)	Legacy ModelBase/ModelBiped classes in the shim plus pose hooks applied to the modern player model	player-animation-library (Player Animator)	1.1.6 (2026-08), MIT, 3.5 M, active	Later: useful for Fisk-style whole-body animation layers, not for plain ModelBiped rotations (legacy model code sets the angles itself every frame)
Animated entity/item models	Legacy ModelBase renderers run as is (LegacyEntityRenderer)	geckolib	4.9.3 (2026-09), MIT, 78.7 M, active	No: legacy mods ship Java models, not GeckoLib assets. Only relevant for an addon that re-skins a legacy entity
Camera roll/shake (Fisk CameraHandler.orient, ViewportEvent.ComputeCameraAngles in FiskHeroesClient)	Own proxy of the legacy GL calls onto the camera event	handycam	2.1.0+1.21.1 (2026-10), LGPL-3.0-only, 35 K, active	No: its API is for new effects; our case is translating arbitrary GL matrix calls, which a shake library cannot express
Gravity / jump / step / reach	Vanilla attributes (Attributes.GRAVITY, STEP_HEIGHT, ENTITY_INTERACTION_RANGE) in the shim, Entity.mcc$set$stepHeight	vanilla 1.21.1 attributes; Pehkui also has STEP_HEIGHT, JUMP_HEIGHT, MOTION, REACH scale types	n/a	Already vanilla. Consider Pehkui STEP_HEIGHT for size-coupled step height (Fisk) if the attribute proves insufficient
Config screens (client/LegacyConfigScreens, GuiConfig/ConfigElement in the 1.12 shim)	Own screens rendering legacy Configuration categories	cloth-config (15.0.140+neoforge, LGPL-3.0-only, 189 M, last build 2024-09; the NeoForge-native Configured has no 1.21.1 NeoForge build on Modrinth)	Works but the 1.12 FML config-GUI API (IConfigElement, GuiConfig) maps poorly to its builder model	Later, optional: only if players ask for nicer screens; keep ours as the fallback
Dimension sky, fog, clouds (LegacyDimensionEffects, LegacyFog, LegacyHorizon)	Own DimensionSpecialEffects	vanilla DimensionSpecialEffects + NeoForge render-stage events	n/a	No library needed
Custom shaders / post effects (legacy GL20 shader code, Fisk glow)	Legacy GL emulation in LegacyGlTexture/DisplayLists	veil (4.5.2, 2026-10, LGPL-3.0-only, 530 K, active)	Powerful render framework, but heavy and shaders in legacy mods are GLSL 1.20 strings, which need translation anyway	No for now; revisit when a legacy shader mod has to work
Particles (legacy EffectRenderer, EntityFX, 1.12 Particle)	Shim particle classes drawing through modern sprites	vanilla Particle + registry; no library found	n/a	No
Multipart blocks (Forge Multipart / CCL / Chicken Bones' cb-multipart)	Legacy mods ship their own ForgeMultipart; the layer translates it like any mod	cb-multipart 3.5.0.155 (2025-12), LGPL-2.1-only, 214 K	Native 1.21.1 multipart for modern mods; unrelated to the legacy API classes the old jar calls	No (a bridge would map TMultiPart to it: large, only if multipart mods (ProjectRed, EnderIO conduits) prove common)
Tinkers' Construct / Mantle (legacy mantle/tconstruct libs)	Mods using Mantle load their own jar	hexa-tinkers-construct-unofficial-port (not an API)	Mantle itself is not on Modrinth for 1.21.1 NeoForge in the search	No
Fluid tanks, item and energy handlers	CapabilityRules/BuiltinAdapters map legacy tanks onto NeoForge capabilities	NeoForge's own capabilities (IFluidHandler, IItemHandler, IEnergyStorage)	n/a	Already the modern API; no extra library
Entity data / capabilities attached to entities (our EntityBridge, ExtendedEntityProperties, 1.12 capabilities)	NeoForge data attachments	NeoForge data attachments (vanilla of NeoForge); cardinal-components has no NeoForge 1.21.1 build	n/a	Already done with attachments
Item animations / item model overrides	LegacyItemRenderer, IsbrhBlockModel	none suitable (tiny-item-animations is a resource-pack tweak, LPUL licence)	n/a	No
Key rebinding and conflicts (client/LegacyKeys, LegacyKeyConflicts)	Own mapping of LWJGL 2 key codes to vanilla KeyMapping	controlling (19.0.5, MIT, 43 M, 2025-03) is a search UI over the vanilla controls screen	Complements; no API we depend on	No
Worldgen helpers (biome modifiers, structure sets for mod dimensions, worldgen/ generators)	Own chunk generators, features hooked on events	lithostitched (1.8.1, MIT, 26 M, 2026-10, active): data-driven worldgen modifiers	Aimed at datapack authors; our generators run legacy code per chunk, no overlap	No
Armor models (LegacyArmorLayer renders ModelBiped armor)	Own layer	armor-model-api (1.1.0+1.21.1-neoforge, MIT, 219 K, 2026-09)	Small and recent; would replace the layer's registration plumbing, not the legacy model drawing	Later: evaluate when armor rendering is next touched
First-person model / skin layers	FirstPersonPose, arm render hooks	first-person-model, 3dskinlayers (custom licence)	Client features, no API to build on	No
Utility libraries many mods bundle (kotlin-for-forge 5.12.0 LGPL-2.1, owo-lib MIT, puzzles-lib MPL-2.0, bookshelf-lib LGPL-2.1, lithostitched)	Not used by the layer	Needed only when a bridged modern mod needs them	n/a	No; leave to the user's pack

How to add one

1. Gradle: Modrinth maven is already declared with the maven.modrinth content filter; add the version to gradle.properties.
2. Required and tiny (MIT/Apache, a few hundred KB): bundle with jarJar(implementation(...)), as for Pehkui.
3. Optional and big: compileOnly, soft-load through the bridge pattern in LibraryBridges.java (class presence check, no direct references in always-loaded classes) and say so in the README config table.
4. Never commit jars; list the licence in the PR.