using UnityEngine;
using System.Collections;
using System.Collections.Generic;
using UnityEngine.UI;
 
[AddComponentMenu("UI/Effects/Gradient")]
public class Gradient :  BaseMeshEffect
{
	[SerializeField]
	private Color32
		topColor = Color.white;
	[SerializeField]
	private Color32
		bottomColor = Color.black;
	
	public override void ModifyMesh (Mesh mesh)
	{
		if (!IsActive ()) {
			return;
		}
 
		Vector3[] vertexList = mesh.vertices;
		int count = mesh.vertexCount;
		if (count > 0) {
			float bottomY = vertexList [0].y;
			float topY = vertexList [0].y;
            
			for (int i = 1; i < count; i++) {
				float y = vertexList [i].y;
				if (y > topY) {
					topY = y;
				} else if (y < bottomY) {
					bottomY = y;
				}
			}
			List<Color32> colors = new List<Color32> ();
			float uiElementHeight = topY - bottomY;
			for (int i = 0; i < count; i++) {
				colors.Add (Color32.Lerp (bottomColor, topColor, (vertexList [i].y - bottomY) / uiElementHeight));
			}
			mesh.SetColors (colors);
		}
	}
}