代码语言：javascript复制
using UnityEngine;
using System.Collections.Generic;
using UnityEngine.UI;
namespace Effects
{
[AddComponentMenu("UI/Effects/Gradient")]
public class Gradient : BaseMeshEffect
{
public enum Type
{
Vertical,
Horizontal
}
[SerializeField]
public Type GradientType = Type.Vertical;
[SerializeField]
[Range(-1.5f, 1.5f)]
public float Offset = 0f;
[SerializeField]
public Color32 StartColor = Color.white;
[SerializeField]
public Color32 EndColor = Color.black;
public override void ModifyMesh(VertexHelper helper)
{
if (!IsActive() || helper.currentVertCount == 0)
return;
List<UIVertex> _vertexList = new List<UIVertex>();
helper.GetUIVertexStream(_vertexList);
int nCount = _vertexList.Count;
switch (GradientType)
{
case Type.Vertical:
{
float fBottomY = _vertexList[0].position.y;
float fTopY = _vertexList[0].position.y;
float fYPos = 0f;
for (int i = nCount - 1; i >= 1; --i)
{
fYPos = _vertexList[i].position.y;
if (fYPos > fTopY)
fTopY = fYPos;
else if (fYPos < fBottomY)
fBottomY = fYPos;
}
float fUIElementHeight = 1f / (fTopY - fBottomY);
UIVertex v = new UIVertex();
for (int i = 0; i < helper.currentVertCount; i )
{
helper.PopulateUIVertex(ref v, i);
v.color = Color32.Lerp(EndColor, StartColor, (v.position.y - fBottomY) * fUIElementHeight - Offset);
helper.SetUIVertex(v, i);
}
}
break;
case Type.Horizontal:
{
float fLeftX = _vertexList[0].position.x;
float fRightX = _vertexList[0].position.x;
float fXPos = 0f;
for (int i = nCount - 1; i >= 1; --i)
{
fXPos = _vertexList[i].position.x;
if (fXPos > fRightX)
fRightX = fXPos;
else if (fXPos < fLeftX)
fLeftX = fXPos;
}
float fUIElementWidth = 1f / (fRightX - fLeftX);
UIVertex v = new UIVertex();
for (int i = 0; i < helper.currentVertCount; i )
{
helper.PopulateUIVertex(ref v, i);
v.color = Color32.Lerp(EndColor, StartColor, (v.position.x - fLeftX) * fUIElementWidth - Offset);
helper.SetUIVertex(v, i);
}
}
break;
default:
break;
}
}
}
}
