CatalystEngine

The public facade of the engine. It coordinates the four subsystems and wires up their internal bindings.

import { CatalystEngine } from 'catalyst-engine';

Constructor

new CatalystEngine(
  statsConfig: Record<string, number>,
  expConfig: IExperienceConfig
)

Parameter	Type	Description
statsConfig	Record<string, number>	Map of statId → base value. Initializes the StatManager.
expConfig	IExperienceConfig	Experience curve configuration.

The constructor instantiates events, stats, exp, skills and wires the ExperienceManager callbacks to the Event Bus (see Architecture).

const engine = new CatalystEngine(
  { hp: 100, attack: 10, defense: 5 },
  { type: 'EXPONENTIAL', baseXP: 100, multiplier: 1.5 }
);

Public properties

Property	Type	Description
stats	StatManager	Management of stats and modifiers.
exp	ExperienceManager	Management of XP and levels.
events	EngineEventBus	Typed event bus.
skills	SkillManager	Skill tree.

They are public: you can access the subsystems directly (e.g. engine.exp.gainExperience(...)).

Methods

addModifier()

addModifier(statId: string, modifier: IStatModifier): void

Adds a modifier to the given stat and emits STAT_CHANGED if the stat exists. It is a shortcut that combines stats.addModifier() with emitting the event.

engine.addModifier('attack', {
  id: 'fire_sword_dmg',
  source: 'fire_sword',
  type: ModifierType.FLAT,
  value: 15,
});

save()

save(): IEngineSaveState

Exports a minimal snapshot of the state (version, timestamp, level+XP, base stat values, unlocked skills). See Persistence.

const snapshot = engine.save();
localStorage.setItem('partita', JSON.stringify(snapshot));

load()

load(saveState: IEngineSaveState): void

Restores the state from a snapshot: it resets level/XP, reapplies the base values, rebuilds the skills (re-injecting the passive modifiers) and re-emits LEVEL_UP to resync the UI.

engine.load(JSON.parse(localStorage.getItem('partita')!));

TIP

Create the engine with the same initial configuration (and load the skill tree, if used) before calling load(). See the note in Persistence.