GoapAction.cs

Source file unity-csharp/game-ai/goap/GoapAction.cs from the GDnD code examples. Download raw file

// GDnD wiki example
// Demonstrates: a GOAP action = name + cost + preconditions + effects (+ where and how long, for execution)
// Related pages: [[goal-oriented-action-planning]]
 
using System.Collections.Generic;
using UnityEngine;
 
// The planner only reads Cost, Preconditions and Effects. Target and Duration are
// for the agent that carries the action out: walk to Target, work for Duration seconds.
public class GoapAction
{
    public string Name;
    public float Cost;
    public Transform Target;
    public float Duration;
    public Dictionary<string, bool> Preconditions = new();
    public Dictionary<string, bool> Effects = new();
 
    public GoapAction(string name, float cost, Transform target, float duration)
    {
        Name = name;
        Cost = cost;
        Target = target;
        Duration = duration;
    }
 
    // Fluent helpers so actions read like a rule: Needs("HasAxe", true).Gives("HasWood", true)
    public GoapAction Needs(string fact, bool value) { Preconditions[fact] = value; return this; }
    public GoapAction Gives(string fact, bool value) { Effects[fact] = value; return this; }
 
    public WorldState ApplyTo(WorldState state)
    {
        var next = new WorldState(state);
        foreach (var effect in Effects) next.Set(effect.Key, effect.Value);
        return next;
    }
 
    public override string ToString() => Name;
}