Overview

The component system provides:

• Per-entity state storage
• Handle-based subsystem integration
• NBT persistence
• Goal registration tracking

Component Structure

Each entity with an attached EcologyComponent contains:

Accessing Components

From Entity

EcologyComponent component = ((EcologyAccess) entity).getComponent();

Reading Handle Data

CompoundTag hungerTag = component.getHandleTag("hunger");
float currentHunger = hungerTag.getFloat("current");

Writing Handle Data

CompoundTag tag = component.getOrCreateHandleTag("hunger");
tag.putFloat("current", newHungerValue);
tag.putLong("last_update", world.getGameTime());

Handle Tags

Each handle stores its state in a separate CompoundTag under the handle’s ID:

BetterEcology
  - hunger
      - current: 75.0
      - max: 100.0
      - last_damage_tick: 12345
  - condition
      - value: 80.0
  - wool
      - wool_stage: 3
      - wool_quality: 0.75

Lifecycle

Attachment

Components are attached via MobEcologyMixin during entity initialization.

Goal Registration

Goals are registered once per entity:

if (!component.areGoalsRegistered()) {
    EcologyHooks.onRegisterGoals(mob);
    component.setGoalsRegistered(true);
}

Ticking

Components are ticked via the mixin hook:

EcologyHooks.onTick(mob);

Persistence

NBT data is saved and loaded via mixin hooks:

// Save
EcologyHooks.onSave(mob, compoundTag);
 
// Load
EcologyHooks.onLoad(mob, compoundTag);

Generation Counter

The generation counter tracks reload events:

1. On /reload, EcologyProfileRegistry.reload() increments generation
2. Components compare their generation with registry generation
3. Stale components refresh their profile reference

This ensures entities pick up configuration changes without requiring respawn.

Common Handle Tags

Hunger Handle

CompoundTag hunger = component.getHandleTag("hunger");
// Fields: current, max, decay_rate, last_damage_tick

Condition Handle

CompoundTag condition = component.getHandleTag("condition");
// Fields: value, last_update

Social Handle

CompoundTag social = component.getHandleTag("social");
// Fields: loneliness, last_social_tick

Age Handle

CompoundTag age = component.getHandleTag("age");
// Fields: age_ticks, is_adult

Thread Safety

• All state stored in NBT tags per-entity
• No shared static state between entities
• Component system provides thread-safe access

Performance

• Component access is O(1) via entity attachment
• Handle tags are lazily created
• No allocation during normal tick operations

See Also

• Architecture
• Behavior System
• Hunger and Condition