Space Select Module >=26.1

The package dev.anvilcraft.lib.v2.space_select provides a visual space selection system. Items implementing the SpaceSelectItem interface allow players to define cubic regions in the world, with support for expand/contract/move/scroll-scale operations. Selection state is stored server-side and rendered as wireframes on the client.

Architecture Overview

1. Data Layer — District records the start and end positions of a selection
2. Server Management — DistrictManager maintains selections keyed by DistrictKey(slot, offhand, item)
3. Client Management — ClientDistrictManager (AnvilLibSpaceSelectClient.MANAGER) tracks selection process and render data
4. Item Layer — SpaceSelectItem interface implements selection logic (select/cancel/onCreateDistrict)
5. Network Layer — SpaceSelectPayload (IServerboundPacket) client→server submits selections
6. Rendering Layer — DistrictRenderer draws selection wireframes, SpaceSelectScrollHandler handles scroll zoom
7. Event Layer — PlayerCreateDistrictEvent triggers on server when a district is created

Data Flow

Player right-clicks selection tool
  → SpaceSelectItem.select(player, pos)
    → ClientDistrictManager.startSelect / endSelect
      → SpaceSelectPayload (C→S, IServerboundPacket)
        → PlayerCreateDistrictEvent
          → Business logic processes the selection

Core API

District

Selection record defined by start/end MutableBlockPos.

District district = District.create(pos1, pos2);
boolean inside = district.contains(x, y, z);

Method	Description
create(BlockPos, BlockPos)	Create district with auto min/max normalization
expand(Direction, int)	Expand in the given direction
contraction(Direction, int)	Contract from the given direction
move(Direction, int)	Move the entire district
scaleOnAxis(Axis, scrollAmount, playerPos, boundingBox, lookAngle)	Scale based on player position and view
getPrimaryAxis(Vec3 lookAngle)	Determine primary axis from view angle
contains(double, double, double)	Point containment check
shape()	Returns the district VoxelShape
color()	Random semi-transparent color based on hashCode

DistrictManager

Server-side selection storage, indexed by DistrictKey.

DistrictManager.DistrictKey key = new DistrictManager.DistrictKey(
    slot,    // inventory slot (-1 for offhand)
    offhand, // whether in offhand
    item     // the item used
);

manager.select(key, district);
manager.clear(key);

SpaceSelectItem

Interface for items. Default logic: right-click tracks selection through AnvilLibSpaceSelectClient.MANAGER ( startSelect→endSelect), sending SpaceSelectPayload on completion.

public class MySelectTool extends Item implements SpaceSelectItem {
    @Override
    public void onCreateDistrict(Player player, ItemStack stack,
                                  BlockPos start, BlockPos end) { }
}

Network Packet

SpaceSelectPayload is IServerboundPacket (client→server), carrying offhand, start, end. Server posts PlayerCreateDistrictEvent on receipt.

Dependency

dependencies {
    implementation "dev.anvilcraft.lib:anvillib-space-select-neoforge-26.1:2.0.0"
}

Notes

• SpaceSelectPayload is serverbound (IServerboundPacket), sent from client to server
• Districts are keyed by (slot, offhand, item) triple — different slots/items have independent selections
• District.start/end are MutableBlockPos for in-place modification
• District color is a random semi-transparent color derived from District.hashCode()
• Depends on module.registrum and module.network
• Client rendering via DistrictRenderer at RenderLevelStageEvent.AfterTranslucentParticles