Developer Reference

This section is for plugin developers who want to drive MovementSync from code or extend its behaviour. For end-user commands, see the Commands page.

Architecture at a glance

MovementSync implements xinbot's Plugin interface. The entry point, xin.bbtt.MovementSync, wires up packet listeners and starts the timing loops, and exposes the main subsystems as singletons:

MovementSync ms = MovementSync.INSTANCE;

ms.getWorld();              // local world model (blocks + entities)
ms.getMovementController(); // queue/executor for Movements
ms.getInventoryManager();   // hotbar, tool selection, block finding

The two timing loops

Loop	Period	Responsibility
Physics simulation	50 ms (20 TPS)	updateMotionTask integrates velocity, applies gravity (-0.08/tick, terminal -3.92), resolves ground collisions, and sends movement packets.
Movement execution	50 ms (20 TPS)	The MovementController ticks the current Movement via a MovementTask.

Keeping bot state (position, velocity, pitch, yaw, onGround) in AtomicReference/AtomicBoolean fields lets the packet-listener threads and the loops share state safely.

Core building blocks

• MovementController — an ordered queue of Movement objects with one executing at a time. Supports append, immediate insert, pause/resume and cancel.
• Movement — the unit of action (walk, jump, dig, place, look, follow a path…). An abstract class with an init / onTick / onStop lifecycle.
• Pathfinding — a D* Lite search over a graph built from pluggable MovementStrategy objects, producing PathSteps that the PathMovement follows.
• World model — a chunk-backed view of blocks and a registry of entities, fed by packet listeners.

Quick example: walk somewhere

import xin.bbtt.MovementSync;
import org.joml.Vector3i;

MovementSync ms = MovementSync.INSTANCE;

// Set a goal and let the pathfinder plan + execute a route to it.
ms.setActiveGoal(new Vector3i(100, 64, -200));
ms.triggerAutoRepath();

triggerAutoRepath() runs D* Lite from the current position to the active goal (or the followed entity), then replaces the controller's queue with a fresh PathMovement. Call requestRepath() to ask the in-flight PathMovement to recompute mid-route.

Helper methods on MovementSync

Method	What it does
jump()	Apply an upward impulse (+0.42) if on the ground.
lookAt(Vector3d)	Queue a LookAtMovement that smoothly turns toward a point.
directLookAt(Vector3d)	Set pitch/yaw instantly toward a point.
getHeadPosition()	Eye position (position + 1.62 on Y).
isRiding() / getVehicleId()	Vehicle state when mounted.
triggerAutoRepath([keepDistance])	Plan and dispatch a path to the active goal / follow target.
requestRepath()	Ask the current PathMovement to replan.

Continue with MovementController for the execution model.