Utilities

Utilities

Registration – util.RegistryUtil

RegistryUtil.registerWithItem(BLOCKS, BLOCK_REGISTRAR, ITEMS, ITEM_REGISTRAR, MyMod.identifier("oak_table"), () -> new TableBlock(props));
RegistryUtil.registerWithoutItem(BLOCKS, BLOCK_REGISTRAR, MyMod.identifier("wall_banner"), () -> new CompletionistWallBannerBlock(props, BANNER));
RegistryUtil.registerItem(ITEMS, ITEM_REGISTRAR, MyMod.identifier("knife"), () -> new SwordItem(...));

Shapes – util.ShapeUtil

VoxelShape east = ShapeUtil.rotateShape(Direction.NORTH, Direction.EAST, northShape);
ShapeUtil.isFaceFull(level, pos);   ShapeUtil.isSolid(level, pos);   ShapeUtil.isFullAndSolid(level, pos);
ShapeUtil.getRelativeHitCoordinatesForBlockFace(hit, facing, blockedFaces); // x/y 0..1 on the clicked face

Everything else – util.LibUtil

tracking(level, pos) (players that see a chunk), fillBucket / emptyBucket, popResourceFromFace, putBlockPos / putBlockPoses / readBlockPoses (NBT), isFire(damageSource), isDamageType(...), convertStackAfterFinishUsing(...) (bowls/bottles after eating), getInPercent, isIndexInRange.

Dyeing – util.DyeHelper

// in useItemOn, with a DyeItem in hand – recolours the block, consumes the dye, plays sound + dye splash
return DyeHelper.dye(stack, dye.getDyeColor(), state, COLOR, level, pos, player);

Items on blocks – render.DisplayItemRenderer

DisplayItemRenderer.renderFlat(stack, poseStack, buffers, light, overlay, level, x, y, z, yaw, scale, seed);    // lying down
DisplayItemRenderer.renderUpright(stack, poseStack, buffers, light, overlay, level, x, y, z, yaw, scale, seed); // standing

Wobble – client.render.WobbleAnimation

The short wobble of stacks and food, for your own block entity renderers:

long start = myBlockEntity.getWobbleStart();
WobbleAnimation.apply(poseStack, level, start, partialTick, WobbleAnimation.seed(pos.asLong()));

Store level.getGameTime() as start time on the client when something changes. isActive(level, start) tells you whether it still runs (10 ticks), angle(...) gives the raw angle, the optional last argument strength scales it.

Also here

Class	Use
util.ImplementedInventory	Container from a NonNullList in two lines
util.StreamCodecUtil	stream codec helpers
render.ClientUtil	light level at a position, GUI item rendering
text.TextEditableBlockEntity + SetTextPacket	blocks with editable text (signs, bowls): implement the interface, send SetTextPacket.sendToServer(...)
client.render.FluidBoxRenderer	renderWaterBox(...): biome tinted water inside a block entity (tubs, tanks, basins)
fabric.datagen.ModelGenHelper (Fabric module)	datagen shortcuts: blockId, variantIds, slabFromTexture …
advancement.SimplePlayerTrigger	"player did X" advancement trigger: register one per event, call trigger(player)