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LINQExtensions and RandomBag
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‎Examples/LINQExtensionsExamples.cs‎

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using System;
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using System.Collections.Generic;
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using System.Text;
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using UnityEngine;
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namespace UnityUtilities.Examples
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{
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public class LINQExtensionsExamples : MonoBehaviour
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{
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[SerializeField] Transform[] elements;
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void Awake()
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{
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int[] items = new int[] {1, 2, 3, 4, 5};
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// Gets a random item
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Debug.Log(items.RandomElement());
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// Shuffles the array in place
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items.Shuffle();
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// Outputs the array on one line. Great for debugging.
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// Example output:
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// "3", "5", "2", "1", "4"
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Debug.Log(items.ToOneLineString());
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}
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void Update()
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{
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if (Input.GetMouseButtonDown(0))
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{
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// Get the x/y position of the click (for an orthographic camera)
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var mousePositionWorld = Camera.main.ScreenToWorldPoint(Input.mousePosition);
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// Gets the element closest to the mouse click
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var nearestElement = elements.Nearest(mousePositionWorld);
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Debug.Log("Nearest element " + nearestElement.name + " at position " + nearestElement.position);
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}
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}
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}
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}

‎Examples/RandomBagExample.cs‎

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using System;
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using System.Text;
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using UnityEngine;
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namespace UnityUtilities.Examples
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{
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public class RandomBagExample : MonoBehaviour
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{
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private enum TetrisPiece
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{
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Line, Square, T, J, L, S, Z
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}
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RandomBag<TetrisPiece> pieceBag;
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void Awake()
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{
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// Get an array with each value of TetrisPiece
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TetrisPiece[] tetrisPieceArray = (TetrisPiece[]) Enum.GetValues(typeof (TetrisPiece));
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// Create the bag containing two instances of every value of TetrisPiece
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pieceBag = new RandomBag<TetrisPiece>(tetrisPieceArray, 2);
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// Gets 50 items from the bag. The bag will be filled with 14 TetrisPieces and
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// automatically refilled with 14 more when needed. No two pieces will ever be
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// more than 14 calls apart - and even that will only happen if that piece was
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// the first and last item in the current 14 piece bag filling.
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StringBuilder str = new StringBuilder();
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for (var i = 0; i < 50; i++)
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{
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str.Append(pieceBag.PopRandomItem());
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str.Append(", ");
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}
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Debug.Log(str);
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// Example output:
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// T, Z, J, Square, Z, S, L, L, S, Line, J, Line, Square, T, Square, Z,
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// S, T, Line, Square, Z, T, J, Line, S, L, J, L, S, Z, Line, J, Line,
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// J, L, L, S, T, T, Z, Square, Square, Z, T, S, Z, J, J, L, Line,
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}
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}
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}

‎LINQExtensions/LINQExtensions.cs‎

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using System;
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using System.Collections.Generic;
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using System.Text;
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using UnityEngine;
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namespace UnityUtilities
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{
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/// <summary>
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/// A collection of extension methods for <see cref="IEnumerable{T}"/>, <see cref="List{T}"/> and arrays.
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/// </summary>
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public static class LINQExtensions
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{
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/// <summary>
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/// Takes a collection, generates values from the items and and returns the item with the lowest generated value.
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/// Useful for example to find the closest item. Reverse the generated values to find the item with the highest generated value.
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///
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/// This returns the same as list.Where(element => predicateValue(valueConverter(element))).OrderBy(valueConverter).First(), but it
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/// a) doesn't need to order the whole list and
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/// b) doesn't need to call valueConverted more than once per element.
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/// </summary>
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/// <typeparam name="TElement">The collection element type.</typeparam>
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/// <typeparam name="TValue">The generated value type.</typeparam>
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/// <param name="list">The list of elements.</param>
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/// <param name="valueConverter">The method to convert an element to a generated value used for ordering.</param>
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/// <param name="predicateValue">A predicate testing whether the generated value is permitted. If true, the element is used; if false, the element is skipped.</param>
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/// <returns>The first element by the generated value in order that succeeded the predicateValue test.</returns>
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public static TElement FirstByGeneratedValue<TElement, TValue>(this IEnumerable<TElement> list, Func<TElement, TValue> valueConverter, Predicate<TValue> predicateValue = null)
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where TValue : IComparable
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{
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var isFirstElement = true;
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TElement bestElement = default(TElement);
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TValue bestValue = default(TValue);
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// For each element...
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foreach (var element in list)
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{
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// Generate its value
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var value = valueConverter(element);
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// Check whether its value is permitted
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if ((predicateValue != null) && (!predicateValue(value)))
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continue;
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// If it's the first permitted element or better than the previous best element...
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if (isFirstElement || (value.CompareTo(bestValue) < 0))
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{
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// ...set it as the best element
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isFirstElement = false;
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bestElement = element;
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bestValue = value;
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}
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}
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return bestElement;
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}
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/// <summary>
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/// Returns the element nearest to the referencePoint and in minimum/maximum range.
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/// </summary>
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/// <typeparam name="TElement">The collection element type. Needs to be a subclass of <see cref="Component"/>.</typeparam>
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/// <param name="list">The list of elements to get the closest.</param>
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/// <param name="referencePoint">A reference point to get the distance from.</param>
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/// <param name="minDistance">Optional: The minimum distance.</param>
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/// <param name="maxDistance">Optional: The maximum distance.</param>
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/// <returns>The element nearest to the referencePoint and in minimum/maximum range.</returns>
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public static TElement Nearest<TElement>(this IEnumerable<TElement> list, Vector3 referencePoint, float minDistance = 0, float maxDistance = float.PositiveInfinity)
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where TElement : Component
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{
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// Create the predicate value from the min/max distance.
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Predicate<float> predicateValue = null;
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if ((minDistance != 0) || !float.IsPositiveInfinity(maxDistance))
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{
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var minDistanceSq = minDistance * minDistance;
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var maxDistanceSq = maxDistance * maxDistance;
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predicateValue = (distanceSq => (distanceSq >= minDistanceSq) && (distanceSq <= maxDistanceSq));
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}
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// Return the nearest element to the reference point in the given range.
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return list.FirstByGeneratedValue(component => (component.transform.position - referencePoint).sqrMagnitude, predicateValue);
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}
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/// <summary>
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/// Shuffles an array in place.
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/// </summary>
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/// <typeparam name="T">The array element type.</typeparam>
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/// <param name="list">The array to shuffle.</param>
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public static void Shuffle<T>(this T[] list)
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{
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var count = list.Length;
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for (int i1 = 0; i1 < count; i1++)
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{
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var i2 = UnityEngine.Random.Range(0, count);
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var element = list[i1];
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list[i1] = list[i2];
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list[i2] = element;
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}
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}
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/// <summary>
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/// Shuffles an list in place.
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/// </summary>
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/// <typeparam name="T">The list element type.</typeparam>
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/// <param name="list">The list to shuffle.</param>
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public static void Shuffle<T>(this List<T> list)
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{
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var count = list.Count;
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for (int i1 = 0; i1 < count; i1++)
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{
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var i2 = UnityEngine.Random.Range(0, count);
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var element = list[i1];
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list[i1] = list[i2];
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list[i2] = element;
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}
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}
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/// <summary>
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/// Returns a random element from the array.
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/// </summary>
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/// <typeparam name="T">The array element type.</typeparam>
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/// <param name="array">The array to return an element from.</param>
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/// <returns>A random element from the array.</returns>
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public static T RandomElement<T>(this T[] array)
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{
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var index = UnityEngine.Random.Range(0, array.Length);
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return array[index];
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}
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/// <summary>
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/// Returns a random element from the list.
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/// </summary>
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/// <typeparam name="T">The list element type.</typeparam>
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/// <param name="array">The list to return an element from.</param>
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/// <returns>A random element from the list.</returns>
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public static T RandomElement<T>(this List<T> list)
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{
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var index = UnityEngine.Random.Range(0, list.Count);
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return list[index];
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}
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/// <summary>
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/// Calls ToString() on every element of the list, puts [encapsulate] directly before and after the result
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/// and then concatenates the results with [seperator] between them.
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/// </summary>
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/// <typeparam name="T">The collection element type.</typeparam>
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/// <param name="list">The collection to concatenate.</param>
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/// <param name="separator">The seperator between entries.</param>
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/// <param name="encapsulate">The string to put directly before and after every item.</param>
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/// <returns>A string containing the ToString() results of all items.</returns>
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public static string ToOneLineString<T>(this IEnumerable<T> list, string separator = ", ", string encapsulate = "\"")
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{
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var useEncapsulate = encapsulate.Length > 0;
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var result = new StringBuilder();
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foreach (var element in list)
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{
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if (result.Length > 0)
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result.Append(separator);
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if (useEncapsulate)
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result.Append(encapsulate);
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result.Append(element);
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if (useEncapsulate)
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result.Append(encapsulate);
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}
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return result.ToString();
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}
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}
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}

‎LINQExtensions/README.md‎

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# LINQExtensions
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A collection of extension methods for `IEnumerable`s, `List`s and arrays.
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## Examples
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# RandomElement/Shuffle/ToOneLineString
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```C#
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int[] items = new int[] {1, 2, 3, 4, 5};
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// Gets a random item
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Debug.Log(items.RandomElement());
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// Shuffles the array in place
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items.Shuffle();
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// Outputs the array on one line. Great for debugging.
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// Example output:
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// "3", "5", "2", "1", "4"
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Debug.Log(items.ToOneLineString());
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```
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# Nearest
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```C#
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public class LINQExtensionsExamples : MonoBehaviour
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{
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[SerializeField] Transform[] elements;
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void Update()
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{
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if (Input.GetMouseButtonDown(0))
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{
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// Get the x/y position of the click (for an orthographic camera)
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var mousePositionWorld = Camera.main.ScreenToWorldPoint(Input.mousePosition);
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// Gets the element closest to the mouse click
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var nearestElement = elements.Nearest(mousePositionWorld);
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Debug.Log("Nearest element " + nearestElement.name + " at position " + nearestElement.position);
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}
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}
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}
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```
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## Dependencies
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None.

‎README.md‎

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## Overview
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* [Countdown](https://github.com/TobiasWehrum/unity-utilities/tree/master/Countdown): Useful for things like cooldowns or spawn delays. It is also helpful for tweening things by using the `PercentElapsed` property.
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* [LINQExtensions](https://github.com/TobiasWehrum/unity-utilities/tree/master/LINQExtensions): A collection of extension methods for `IEnumerable`s, `List`s and arrays.
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* [NoiseOutputValue](https://github.com/TobiasWehrum/unity-utilities/tree/master/NoiseOutputValue): Enter a range and a speed in the editor, get an output value that fluctuates over time using [Perlin Noise](http://docs.unity3d.com/ScriptReference/Mathf.PerlinNoise.html).
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* [Range](https://github.com/TobiasWehrum/unity-utilities/tree/master/Range): Editable data types that takes an int/float range. Used for things like "Spawn 2 to 4 enemies."
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* [RandomBag](https://github.com/TobiasWehrum/unity-utilities/tree/master/RandomBag): A `RandomBag` gives you random items from a group while ensuring that in a certain interval every item was given back the same number of times.
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* [Range](https://github.com/TobiasWehrum/unity-utilities/tree/master/Range): Editable data types that take an `int`/`float` range. Used for things like "Spawn 2 to 4 enemies."
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* [Singleton](https://github.com/TobiasWehrum/unity-utilities/tree/master/Singleton): Allows easy and convenient creation of a Singleton. Optionally makes a Singleton persist between scenes while ensuring that only one exists.
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## Usage
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The class documentation is available [here](http://tobiaswehrum.github.io/UnityUtilities/html/annotated.html).
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## Changelog
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* 2015-05-09: Added the [class documentation website](http://tobiaswehrum.github.io/UnityUtilities/html/annotated.html).
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* 2015-05-08: Added [Countdown](https://github.com/TobiasWehrum/unity-utilities/tree/master/Countdown), [NoiseOutputValue](https://github.com/TobiasWehrum/unity-utilities/tree/master/NoiseOutputValue), [Range](https://github.com/TobiasWehrum/unity-utilities/tree/master/Range) and [Singleton](https://github.com/TobiasWehrum/unity-utilities/tree/master/Singleton).
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* 2016-05-15: Added [LINQExtensions](https://github.com/TobiasWehrum/unity-utilities/tree/master/LINQExtensions) and [RandomBag](https://github.com/TobiasWehrum/unity-utilities/tree/master/RandomBag).
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* 2016-05-09: Added the [class documentation website](http://tobiaswehrum.github.io/UnityUtilities/html/annotated.html).
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* 2016-05-08: Added [Countdown](https://github.com/TobiasWehrum/unity-utilities/tree/master/Countdown), [NoiseOutputValue](https://github.com/TobiasWehrum/unity-utilities/tree/master/NoiseOutputValue), [Range](https://github.com/TobiasWehrum/unity-utilities/tree/master/Range) and [Singleton](https://github.com/TobiasWehrum/unity-utilities/tree/master/Singleton).

‎RandomBag/README.md‎

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# RandomBag
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A RandomBag ensures that per interval [fillings * itemCount], every different item in it will be given back [fillings] times. Once the bag is empty, it is automatically refilled, either from a fixed array or by calling a delegate.
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An example for that is used in [some implementations of Tetris](http://tetris.wikia.com/wiki/Random_Generator). The bag is filled with one instance (fillings=1) of each of the seven different pieces. Every time the next piece is needed, a random one is taken out of the bag until the bag is empty. That way, any two pieces are never longer than 14 pulls apart - and even that is only the case if the first and the last piece in the bag are the same one.
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## Example
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```C#
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public class RandomBagExample : MonoBehaviour
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{
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private enum TetrisPiece
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{
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Line, Square, T, J, L, S, Z
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}
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RandomBag<TetrisPiece> pieceBag;
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void Awake()
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{
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// Get an array with each value of TetrisPiece
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TetrisPiece[] tetrisPieceArray = (TetrisPiece[]) Enum.GetValues(typeof (TetrisPiece));
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// Create the bag containing two instances of every value of TetrisPiece
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pieceBag = new RandomBag<TetrisPiece>(tetrisPieceArray, 2);
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// Gets 50 items from the bag. The bag will be filled with 14 TetrisPieces and
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// automatically refilled with 14 more when needed. No two pieces will ever be
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// more than 14 calls apart - and even that will only happen if that piece was
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// the first and last item in the current 14 piece bag filling.
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StringBuilder str = new StringBuilder();
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for (var i = 0; i < 50; i++)
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{
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str.Append(pieceBag.PopRandomItem());
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str.Append(", ");
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}
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Debug.Log(str);
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// Example output:
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// T, Z, J, Square, Z, S, L, L, S, Line, J, Line, Square, T, Square, Z,
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// S, T, Line, Square, Z, T, J, Line, S, L, J, L, S, Z, Line, J, Line,
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// J, L, L, S, T, T, Z, Square, Square, Z, T, S, Z, J, J, L, Line,
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}
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}
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```
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## Dependencies
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* [LINQExtensions](https://github.com/TobiasWehrum/unity-utilities/tree/master/LINQExtensions)

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