[Unity]UIにグラデーションをつける

DirectionalGradation.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
using System;

// Unity5.5.1p4

namespace TSKT
{
    public class DirectionalGradation : BaseMeshEffect
    {
        [SerializeField]
        Color32 color = Color.white;

        [SerializeField]
        [Range(0f, 360f)]
        float angle = 0f;

        public override void ModifyMesh(VertexHelper vh)
        {
            if (!IsActive())
            {
                return;
            }

            var list = UIVerticesPool.Get();
            vh.GetUIVertexStream(list);
            ModifyMesh(list);
            vh.Clear();
            vh.AddUIVertexTriangleStream(list);
        }

        void ModifyMesh(List<UIVertex> list)
        {
            float max = float.MinValue;
            float min = float.MaxValue;

            var vector = new Vector2(Mathf.Cos(Mathf.Deg2Rad * angle), Mathf.Sin(Mathf.Deg2Rad * angle));
            foreach(var it in list)
            {
                var dot = it.position.x * vector.x + it.position.y * vector.y;
                max = Mathf.Max(dot, max);
                min = Mathf.Min(dot, min);
            }

            if (max == min)
            {
                return;
            }

            for (int i = 0; i < list.Count; ++i)
            {
                var vertex = list[i];

                var dot = vertex.position.x * vector.x + vertex.position.y * vector.y;
                var t = Mathf.InverseLerp(min, max, dot);
                var c = Color.Lerp(Color.white, color, t);
                vertex.color = c * vertex.color;
                list[i] = vertex;
            }
        }
    }
}

こっちも必要
https://gist.github.com/enue/9999df944dd39bd1fc3a2677e14db26e