AI Goals and Riding

AI goals

EntityDefinition.builder(texture)
        .goal(4, SeekGlowBlockGoal::new)       // a new goal object for each mob
        .build();

SeekGlowBlockGoal.java

final class SeekGlowBlockGoal implements AiGoal {   // canStart, shouldContinue, start, tick, stop

    private BlockPos target;

    @Override
    public boolean canStart(MobView mob) {
        target = find(mob.world(), mob.blockPos());   // find a glowing block nearby
        return target != null;
    }

    @Override
    public boolean shouldContinue(MobView mob) {
        return mob.isNavigating();
    }

    @Override
    public void start(MobView mob) {
        mob.navigateTo(target.x() + 0.5, target.y(), target.z() + 0.5, 1.0);
    }

    @Override
    public void tick(MobView mob) {
        mob.lookAt(target.x() + 0.5, target.y() + 0.5, target.z() + 0.5);
    }

    @Override
    public void stop(MobView mob) {
        mob.stopNavigating();
    }
}

• The game's goal scheduler runs it on the server thread.
• A lower number means higher priority. Goals that use the same control (GoalControl: MOVE, LOOK, JUMP, TARGET) do not run at the same time. Override controls() to set the controls a goal uses.
• The priorities of the default goals are 0 (floating), 1 (fleeing), 2 (attacking), 3 (tempting), 5 (wandering), and 6–7 (looking around).
• targetGoal(priority, factory) is a goal that picks the attack target.
• The factory is called once per mob, so a goal object can hold state.

MobView

Method	Meaning
navigateTo(x, y, z, speed)	Start pathfinding
isNavigating(), stopNavigating()	Pathfinding state, and stopping it
lookAt(x, y, z)	Gaze
target(), setTarget(living)	Attack target

Movement and riding

EntityDefinition.builder(texture)
        .rideable(true)                        // use with an empty hand to mount, steer with movement keys
        .noGravity().notPushable();

entity.setVelocity(0, 0.5, 0);
player.startRiding(golem);

Movement-related methods of EntityView:

Method	Meaning
velocity(), setVelocity(x, y, z)	Velocity (Vector3). For players, it is sent to the client
yaw(), pitch(), setRotation(yaw, pitch)	Direction
hasNoGravity(), setNoGravity(bool)	Gravity
isOnGround()	Whether it is on the ground
vehicle(), passengers(), startRiding(vehicle), stopRiding()	Mount and passengers

• A mob with rideable(true) is steered like a horse. As with a horse, the riding player's client computes the steering movement.
• rideable(false) can be ridden but not steered.

Needs human verification

You cannot automate key input, so a person must check mount steering by hand.