127 lines
4.0 KiB
C#
127 lines
4.0 KiB
C#
using System.Collections;
|
|
using System.Collections.Generic;
|
|
using UnityEngine;
|
|
|
|
namespace MoreMountains.Tools
|
|
{
|
|
/// <summary>
|
|
/// A loot table helper that can be used to randomly pick objects out of a weighted list
|
|
/// This design pattern was described in more details by Daniel Cook in 2014 in his blog :
|
|
/// https://lostgarden.home.blog/2014/12/08/loot-drop-tables/
|
|
///
|
|
/// This generic LootTable defines a list of objects to loot, each of them weighted.
|
|
/// The weights don't have to add to a certain number, they're relative to each other.
|
|
/// The ComputeWeights method determines, based on these weights, the chance percentage of each object to be picked
|
|
/// The GetLoot method returns one object, picked randomly from the table
|
|
/// </summary>
|
|
/// <typeparam name="T"></typeparam>
|
|
/// <typeparam name="V"></typeparam>
|
|
public class MMLootTable<T,V> where T:MMLoot<V>
|
|
{
|
|
/// the list of objects that have a chance of being returned by the table
|
|
[SerializeField]
|
|
public List<T> ObjectsToLoot;
|
|
|
|
/// the total amount of weights, for debug purposes only
|
|
[Header("Debug")]
|
|
[MMReadOnly]
|
|
public float WeightsTotal;
|
|
|
|
protected float _maximumWeightSoFar = 0f;
|
|
protected bool _weightsComputed = false;
|
|
|
|
/// <summary>
|
|
/// Determines, for each object in the table, its chance percentage, based on the specified weights
|
|
/// </summary>
|
|
public virtual void ComputeWeights()
|
|
{
|
|
if (ObjectsToLoot == null)
|
|
{
|
|
return;
|
|
}
|
|
|
|
if (ObjectsToLoot.Count == 0)
|
|
{
|
|
return;
|
|
}
|
|
|
|
_maximumWeightSoFar = 0f;
|
|
|
|
foreach(T lootDropItem in ObjectsToLoot)
|
|
{
|
|
if(lootDropItem.Weight >= 0f)
|
|
{
|
|
lootDropItem.RangeFrom = _maximumWeightSoFar;
|
|
_maximumWeightSoFar += lootDropItem.Weight;
|
|
lootDropItem.RangeTo = _maximumWeightSoFar;
|
|
}
|
|
else
|
|
{
|
|
lootDropItem.Weight = 0f;
|
|
}
|
|
}
|
|
|
|
WeightsTotal = _maximumWeightSoFar;
|
|
|
|
foreach(T lootDropItem in ObjectsToLoot)
|
|
{
|
|
lootDropItem.ChancePercentage = ((lootDropItem.Weight) / WeightsTotal) * 100;
|
|
}
|
|
|
|
_weightsComputed = true;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Returns one object from the table, picked randomly
|
|
/// </summary>
|
|
/// <returns></returns>
|
|
public virtual T GetLoot()
|
|
{
|
|
if (ObjectsToLoot == null)
|
|
{
|
|
return null;
|
|
}
|
|
|
|
if (ObjectsToLoot.Count == 0)
|
|
{
|
|
return null;
|
|
}
|
|
|
|
if (!_weightsComputed)
|
|
{
|
|
ComputeWeights();
|
|
}
|
|
|
|
float index = Random.Range(0, WeightsTotal);
|
|
|
|
foreach (T lootDropItem in ObjectsToLoot)
|
|
{
|
|
if ((index > lootDropItem.RangeFrom) && (index < lootDropItem.RangeTo))
|
|
{
|
|
return lootDropItem;
|
|
}
|
|
}
|
|
|
|
return null;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// A MMLootTable implementation for GameObjects
|
|
/// </summary>
|
|
[System.Serializable]
|
|
public class MMLootTableGameObject : MMLootTable<MMLootGameObject, GameObject> { }
|
|
|
|
/// <summary>
|
|
/// A MMLootTable implementation for floats
|
|
/// </summary>
|
|
[System.Serializable]
|
|
public class MMLootTableFloat : MMLootTable<MMLootFloat, float> { }
|
|
|
|
/// <summary>
|
|
/// A MMLootTable implementation for strings
|
|
/// </summary>
|
|
[System.Serializable]
|
|
public class MMLootTableString : MMLootTable<MMLootString, string> { }
|
|
}
|