Random animations sequence utility

SpineRandomAnimationsSequence.cs

using UnityEngine;
using System;
using Spine;
using Spine.Unity;

namespace GentleGiant.Animation {
    public class SpineRandomAnimationsSequence : MonoBehaviour {
        [Serializable]
        public class AnimationChance {
            [SpineAnimation(dataField = "skeletonAnimation")]
            public string animationName;
            public float chance;
            public int maxRepeats;
            [NonSerialized]
            public int repeats;
        }

        [SerializeField] SkeletonAnimation skeletonAnimation;
        [SerializeField] AnimationChance[] animations;

        private AnimationChance lastAnimation;

        protected void Start() {
            skeletonAnimation.AnimationState.Complete += SkeletonAnimationStateOnComplete;
            PlayAnimation();
        }

        private void SkeletonAnimationStateOnComplete(TrackEntry trackEntry) {
            PlayAnimation();
        }

        private void PlayAnimation() {
            var animationEntry = ChooseRandomWithChances(animations);
            if (lastAnimation == animationEntry && lastAnimation.maxRepeats > 0) {
                ++lastAnimation.repeats;
                if (lastAnimation.repeats >= lastAnimation.maxRepeats) {
                    while (lastAnimation == animationEntry) {
                        animationEntry = ChooseRandomWithChances(animations);
                    }
                    lastAnimation.repeats = 0;
                    animationEntry.repeats = 0;
                }
            } else {
                animationEntry.repeats = 0;
            }
            lastAnimation = animationEntry;
            skeletonAnimation.AnimationState.SetAnimation(0, animationEntry.animationName, false);
        }
        
        /// <summary>
        /// Chooses a random element from the array.
        /// Chance values don't have to sum to 1.
        /// </summary>
        public static AnimationChance ChooseRandomWithChances(AnimationChance[] array) {
            var sumChance = 0f;
            foreach (var t in array) {
                sumChance += t.chance;
            }

            var rnd = UnityEngine.Random.value * sumChance;

            foreach (var t in array) {
                rnd -= t.chance;
                // Checking for less than 0 so if rnd was 0, something with 0 chance
                // won't get picked.
                if (rnd < 0f) {
                    return t;
                }
            }
            return array[array.Length - 1];
        }
    }
}