Minecraft 1.19.3 -> 1.19.4 Mod Migration Primer

1193-1194-primer.md

Minecraft 1.19.3 -> 1.19.4 Mod Migration Primer

This is a high level, non-exhaustive overview on how to migrate your mod from 1.19.3 to 1.19.4 using Forge.

This primer is licensed under the Creative Commons Attribution 4.0 International, so feel free to use it as a reference and leave a link so that other readers can consume the primer.

If there's any incorrect or missing information, please leave a comment below. Thanks!

Pack Changes

There are a number of user-facing changes that are part of vanilla which are not discussed below that may be relevant to modders. You can find a list of them on Misode's version changelog.

DamgeType and DamageSources

Damage sources have been rewritten to define common data which should be static between different sources. As such, each DamageSource now takes in a DamageType which defines this information. DamageTypes are created in json like any other datapack registry.

The main DamageType record constructor takes in the following arguments:

Parameter	Type	Decsription
msgId	String	A string used within a localization key (typically preceded by death.attack.).
scaling	DamageScaling	When the damage caused by the type should scale according to difficulty.
exhaustion	float	How much food exhaustion should occur when the damage source is applied to the player.
effects	DamageEffects	The sound to be played when the type is applied to an entity.
deathMessageType	DeathMessageType	How the death message should be structured for the type. Should almost always be DEFAULT.

A DamageSource is now treated as final class (it's not actually final, so it can still be extended if needed) which takes in some combination of the following parameters:

Parameter	Type	Decsription
type	Holder<DamageType>	The damage type, typically obtained from the RegistryAccess.
causingEntity	Entity	The entity who caused the damage directly or through the #directEntity.
directEntity	Entity	The entity who directly inflicted the damage.
damageSourcePosition	Vec3	The position the damage source took place.

The damage sources are now constructed in DamageSources which can be obtained from the Level via #damageSources. Every Entity also has a redirect method to the level via #damageSources.

DamageSourcePredicate

The DamageSourcePredicate for criteria triggers has been rewritten to take in a list of TagPredicates for the DamageType applied along with the direct and causing (source) entity.

TagPredicates check if the specific object is either within or not within a tag (triggered by the expected boolean flag).

GUI Changes

There have been a number of GUI changes which expands upon existing methods, restructures components, and reorganizes their locations.

GuiComponent

All GuiComponent methods are now static. Additionally, new methods were added to draw information to the screen: #renderOutline and #blitNineSliced. #setBlitOffset and #getBlitOffset have been removed and are now performed using the PoseStack by translating the z-axis.

ScreenRectangle

A new class called ScreenRectangle to specify a rectangle. This is typically used for scissors and layouts; however, it could also be used in standard rendering.

ComponentPath

Logic relating to how components are focused and executed are now handled through ComponentPaths which now handle the responsibility of a for loop on a list.

More PoseStack additions

The PoseStack has been added to a number of methods to properly transform the drawn information onto the screen space.

Widget Restructing

A number of widgets have been restructured or moved into different classes to handle some common logic.

The following components have been added:

• net.minecraft.client.gui.components.TabButton and by extension net.minecraft.client.gui.components.tabs.TabNavigationBar
• net.minecraft.client.gui.components.AbstractStringWidget and by extension net.minecraft.client.gui.components.MultiLineTextWidget
• net.minecraft.client.gui.components.ImageWidget
• net.minecraft.client.gui.components.TextAndImageButton

In addition, the following components were moved, renamed, or modified:

• net.minecraft.client.gui.components.CenteredStringWidget -> net.minecraft.client.gui.components.StringWidget
• net.minecraft.client.gui.components.AbstractWidget#renderButton -> #renderWidget
• net.minecraft.client.gui.components.AbstractWidget#getYImage reworked into AbstractButton#getTextureY where it returns the texture coordinate rather than the texture index

Layout Components

Layout components, such as the FrameWidget, within net.minecraft.client.gui.components have been moved to net.minecraft.client.gui.layouts. Additionally, they have been restructure to consume widgets to properly move them to where they need to be displayed rather than having each layout be its own widget. As such, AbstractContainerWidget was removed.

Font DisplayMode

Font#drawInBatch and any subsequent delegates (e.g. FontRenderer#drawInBatch) now take in a Font$DisplayMode instead of a boolean to determine how the font should be displayed.

Entity Interfaces

Entity logic has been abstracted even more into three new interfaces: Attackable, Targeting, and TraceableEntity. The Attackable interface indicates the entity can be attacked and stores the last attacker via #getLastAttacker. The Targeting interface indicates the entity can target another entity and stores the value via #getTarget. Finally, the TraceableEntity interface means that the entity's creation and initial action can be traced back to another entity, which can be obtained via #getOwner.

TraceableEntity should not be confused with OwnableEntity. Traceables are typically used for projectiles or entities fired from or triggered by another entity while ownables are typically for tamed animals.

Blocks and Sounds

Blocks have a few changes regarding their internal implementation and data structures.

The BlockBehaviour$OffsetType passed into BlockBehavior$Properties#offsetType now redirects to BlockBehavior$OffsetFunction which takes in a BlockState, BlockGetter, and BlockPos and returns the amount to offset the model by. This is currently not exposed to the end user.

A new record has been made to store common properties associated with a type, aptly named BlockSetType. This takes in the SoundType for the block in addition to sound events for flicking on or off a door, trapdoor, pressure plate, and button. Following this trend, WoodTypes now take in the BlockSetType in addition to SoundTypes for the wood and hanging sign along with SoundEvents for the fence gate. WoodTypes are also registered via the #register method instead of #create:

public static final WoodType TEST_WOOD_TYPE = WoodType.register(new WoodType(new ResourceLocation(MODID, "test").toString(), BlockSetType.ACACIA));

BlockSetTypes can be created and registered using the constructor and BlockSetType#register, repsectively, after the SoundEvent registry event has fired but before the Block registry event.

Creative Tabs

Creative Tabs have slightly changed as now when populating the generator, the method provides CreativeModeTab$ItemDisplayParameters and an CreativeModeTab$Output. The parameters holds the list of enabled feature, whether the player has permission, and a lookup provider on all the registries.

Custom creative tabs from the previous primer are now slightly modified to take in the two parameters:

// Registered on the MOD event bus
// Assume we have RegistryObject<Item> and RegistryObject<Block> called ITEM and BLOCK
@SubscribeEvent
public void buildContents(CreativeModeTabEvent.Register event) {
  event.registerCreativeModeTab(new ResourceLocation(MOD_ID, "example"), builder ->
    // Set name of tab to display
    builder.title(Component.translatable("item_group." + MOD_ID + ".example"))
    // Set icon of creative tab
    .icon(() -> new ItemStack(ITEM.get()))
    // Add default items to tab
    .displayItems((params, output) -> {
      output.accept(ITEM.get());
      output.accept(BLOCK.get());
    })
  );
}

Additionally, net.minecraftforge.event.CreativeModeTabEvent$BuildContents can access the parameters via #getParameters. The other methods now delegate to the parameters for better compatibility when updating from 1.19.3.

Removal of com.mojang.bridge.*

Mojang's javabridge library has been removed as a dependency from Minecraft. As such, all of the redirected counterparts to the bridge (such as com.mojang.bridge.game.PackType and com.mojang.bridge.game.GameVersion) are now handled by their references or implementations (net.minecraft.server.packs.PackType and net.minecraft.WorldVersion respectively).

Spawn Events Refactor

As of 45.0.23, spawn events have been completely refactored. For starters, LivingSpawnEvent has been renamed to MobSpawnEvent. Even further CheckSpawn and SpecialSpawn hae been merged into a single event: FinalizeSpawn. FinalizeSpawn can be canceled to prevent Mob#finalizeSpawn from being called while the entity itself can be prevent using FinalizeSpawn#setSpawnCancelled.

If you want to learn more about this event and the technical changes, see the blog post.

Minor Additions, Changes, and Removals

The following is a list of useful or interesting additions, changes, and removals that do not deserve their own section in the primer.

New Registries

In addition to DamageTypes, a static registry for decorated pot patterns and datapack registries for trim materials, trim patterns, and MultiNoiseBiomeSourceParameterList have been added.

Additionally, Forge has added a new static registry for ItemDisplayContexts aptly named forge:display_contexts for registering perspectives an item may be rendered within, replacing custom TransformTypes. There can only be at most 256 display contexts.

New Codecs

A number of new codecs have been added or changed:

• com.mojang.math.Transformation#CODEC
• net.minecraft.util.ExtraCodecs#QUATERNIONF_COMPONENTS
• net.minecraft.util.ExtraCodecs#AXISANGLE4F
• net.minecraft.util.ExtraCodecs#MATRIX4F

Sprite Registration Refactoring

First, net.minecraft.client.particle.ParticleProvider$Sprite is added, which is a functional interface used to create a TextureSheetParticle with only one texture. This is used as a wrapper around a ParticleEngine$SpriteParticleRegistration when the particle does not need access to the SpriteSet.

Additionally, as of 45.0.25, all net.minecraftforge.client.event.RegisterParticleProvidersEvent#register methods have been deprecated for removal, opting to switch to method names which better specify their usecase:

• #register(ParticleType, ParticleProvider) -> #registerSpecial
• #register(ParticleType, ParticleProvider$Sprite) -> #registerSprite
• #register(ParticleType, ParticleEngine$SpriteParticleRegistration) -> #registerSpriteSet

Additions

• GlintAlpha - A new GLSL shader uniform which changes the glint strength based on the accessibility option of a similar name.
• net.minecraft.advancements.Advancement#getRoot - Gets the root of an advancement.
• net.minecraft.client.model.geom.builders.CubeListBuilder#addBox can now take in a set of directions which indicates the visible faces to render of a given box. This is baked into the net.minecraft.client.model.geom.ModelPart$Cube when adding the polygons.
• net.minecraft.client.model.AgeableHierarchicalModel - A parallel to net.minecraft.client.modelAgeableListModels for HierarchialModels.
• net.minecraft.client.model.HumanoidArmorModel - An extension of net.minecraft.client.model.HumanoidModel for armor models.
• com.mojang.blaze3d.vertex.PoseStack#rotateAround - Rotates a quaternion around a point.
• net.minecraft.commands.arguments.HeightmapTypeArgument - A common argument for specifying which heightmap to use.
• net.minecraft.gametest.framework.GameTestHelper#continuouslyUse - A helper test method to force a player to use an item on a certain block position every tick.
• net.minecraft.util.ParticleUtils#spawnParticleBelow - Spawns a particle half a block below the specified position
• net.minecraft.world.inventory.Slot#setByPlayer - A method indicating that a player changed the slot in some capacity.
• net.minecraft.world.effect.MobEffectInstance#endsWithin - Returns whether the mob effect will expire in x ticks.
• net.minecraft.world.entity.Entity#getControlledVehicle - Returns the vehicle if it is being controlled by this entity.
• net.minecraft.world.phys.AABB#distanceToSqr - Gets the squared distance to the provided vector.
• net.minecraft.world.phys.Vec3#atLowerCornerWithOffset - Offsets the vector by the specified x, y, z coordinates.
• net.minecraft.world.phys.Vec3#atCenterOf - Offsets the vector by 0.5 in all directions.
• net.minecraft.data.advancements.AdvancementSubProvider#createPlaceholder - Creates a dummy advancement to use as a parent for another advancement.
• net.minecraft.network.FriendlyByteBuf#readJsonWithCodec and #writeJsonWithCodec` - Writes a encoded object to json into a buffer.
  • Tag implementations #readWithCodec and #writeWithCodec are currently deprecated.
• net.minecraft.client.renderer.texture.Dumpable - Dumps the contents of the object to a file (DynamicTexture, TextureAtlas).
• net.minecraft.world.entity.LivingEntity#remove - Removes the entity from the level for the specified reason.
• net.minecraft.world.entity.ai.Brain#clearMemories - Clears all the memory values of an entity's brain.
• com.mojang.math.MatrixUtil contains some additional jacobi matrix methods.
• net.minecraft.world.level.GrassColor#getDefaultColor - Gets the default color of grass.
• net.minecraft.network.syncher.SynchedEntityData#set(EntityDataAccessor, T, boolean) - Boolean parameter added to force a sync of the entity data.
• net.minecraftforge.fml.CrashReportCallables can now be supplied a callable which will append to the system report when the boolean supplier returns true.

Changes

• net.minecraft.world.level.biome.Biome#isHumid -> #hasPrecipitation
• net.minecraft.world.level.biome.Biome#getPrecipitation() -> #getPrecipitationAt(BlockPos)
• net.minecraft.world.entity.LivingEntity#animationSpeedOld, #animationSpeed, and #animationPosition has been bundled into one public object on the entity known as WalkAnimationState.
• net.minecraft.server.packs.repository.PackRepository#addPack and #removePack now return a boolean on whether the action was successful.
• net.minecraft.client.gui.screens.worldselection.WorldGenSettingsComponent -> WorldCreationUiState
• net.minecraft.client.renderer.block.model.ItemTransforms$TransformType -> net.minecraft.world.item.ItemDisplayContext
• net.minecraft.client.resources.metadata.language.LanguageMetadataSectionSerializer -> LanguageMetadataSection#CODEC
• net.minecraft.world.item.crafting.UpgradeRecipe -> LegacyUpgradeRecipe
  • Deprecated for removal; replaced by SmithingRecipe, SmithingTransformRecipe, and SmithingTrimRecipe
• net.minecraft.data.recipes.UpgradeRecipeBuilder -> LegacyUpgradeRecipeBuilder
  • Deprecated for removal; replaced by SmithingTransformRecipeBuilder and SmithingTrimRecipeBuilder
• net.minecraft.data.worldgen.biome.Biomes -> BiomeData
• net.minecraft.world.item.Wearable -> Equipable
• net.minecraft.world.item.crafting.Recipe#assemble(C) and #getResultItem() -> #assemble(C, RegistryAccess) and #getResultItem#(RegistryAccess)
• net.minecraft.world.entity.Entity#rideableUnderWater -> #dismountsUnderwater
• net.minecraft.world.entity.PlayerRideableJumping#canJump(Player) -> #canJump()
• net.minecraft.data.tags.TagsProvider now can take in a CompletableFuture<TagsProvider.TagLookup<T>> if tags need to be accessed from other TagProviders. A lookup can be obtained via TagsProvider#contentsGetter.
• net.minecraft.world.item.ArmorItem now take in a delegate to the EquipmentSlot called ArmorItem$Type within their constructors and associated references.
• net.minecraft.core.BlockPos constructors that take in doubles should migrate to using BlockPos#containing.
• net.minecraft.world.level.biome.MobSpawnSettings$SpawnerData#minCount and #maxCount must be positive values.

Removals

• net.minecraft.world.level.biome.Biome#hasDownfall as it was only used by the #isHumid check, now #hasPrecipitation.
• com.mojang.blaze3d.systems.RenderSystem#enableTexture and #disableTexture as they have not been doing anything other than adding extra cycles to the logic execution.

notice.md

All primers have been migrated to a separate repo. I will still answer questions and provide updates as required to this version as well.

how do i do 1.21 modding?

is there any huge differnce like can i use the 1.19.4 code for an 1.21 mod?

I would join one of the many modding discords if you want to ask modding related questions. However, to specify, there have been a lot of changes between 1.19.4 -> 1.21, meaning that a good portion of the codebase will likely not work. Out of the primers I have written, they can be found below:

https://gist.github.com/ChampionAsh5357/cf818acc53ffea6f4387fe28c2977d56
https://gist.github.com/ChampionAsh5357/53b04132e292aa12638d339abfabf955
https://gist.github.com/ChampionAsh5357/d895a7b1a34341e19c80870720f9880f