ugui之圆角矩形头像实现

这个是参考大神的修改了一下渲染方式实现的，可以去查看原帖的，原贴是圆形头像，原理讲的非常详细

点击这里

我写的这个只支持正方形图片，效果是酱紫的~

一共三个代码，还需要两个代码，原帖里都有的，我只是修改了其中一个。

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

 [AddComponentMenu("UI/Circle Image")]
 public class CircleImage1 : BaseImage {
     // Use this for initialization
     void Awake () {
         innerVertices = new List<Vector3>();
         outterVertices = new List<Vector3>();
     }

     // Update is called once per frame
     void Update () {

     }

     [Range(, )]
     public float scale = 1f;

     [Range(, )]
     public int segements = ;

     private List<Vector3> innerVertices;
     private List<Vector3> outterVertices;

     protected override void OnPopulateMesh(VertexHelper vh)
     {  vh.Clear();
         Rect pixelAdjustedRect = this.GetPixelAdjustedRect();

         Vector4 uv = overrideSprite != null ? DataUtility.GetOuterUV(overrideSprite) : Vector4.zero;
         //Debug.LogError("uv:" + uv+","+uv.w+","+uv.x+","+uv.y+","+uv.z);

          Vector2 u = new Vector2(, );
         float w = pixelAdjustedRect.width;

         #region
         //
         for (int i =; i < segements+; i++)
         {
             UIVertex uivertex = new UIVertex();
             uivertex.color = color;
             if (i ==)
             {
                 //半径*
                 uivertex.uv0 = new Vector2(uv.x + (scale / ) * (uv.z - uv.x) * ( - Mathf.Sin(i *  / segements)), uv.y + (scale / ) * (uv.w - uv.y) * ( - Mathf.Cos(i *  / segements)));
                 u = new Vector2((scale / ) * ( - Mathf.Sin(i *  / segements)),(scale / ) * ( - Mathf.Cos(i *  / segements)));
             }
             else
             {
                 uivertex.uv0 = new Vector2(uv.x + (scale / ) * (uv.z - uv.x) * ( - Mathf.Sin(Mathf.PI / (180f / (i *  / segements)))), uv.y + (scale / ) * (uv.w - uv.y) * ( - Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))));
                 u = new Vector2((scale / )  * ( - Mathf.Sin(Mathf.PI / (180f / (i *  / segements)))),(scale / )  * ( - Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))));
             }
             uivertex.position = new Vector3(w * u.x - w / , w * u.y - w / );

             vh.AddVert(uivertex);
         }
         //
         for (int i = ; i < segements + ; i++)
         {
             UIVertex uivertex = new UIVertex();
             uivertex.color = color;
             if (i == )
             {
                uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (scale / ) * ( - Mathf.Cos(i *  / segements)), uv.y + (uv.w - uv.y) * (( - scale / ) + (scale / ) * Mathf.Sin(i *  / segements)));
                 u = new Vector2((scale / ) - (scale / ) * Mathf.Cos(i *  / segements), ( - scale / ) + (scale / ) * Mathf.Sin(i *  / segements));
             }
             else
             {
                 uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (scale / ) * ( - Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))), uv.y + (uv.w - uv.y) * (( - scale / ) + (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements)))));
                 u = new Vector2( (scale / ) * ( - Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))), ( - scale / ) + (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements))));
             }
             uivertex.position = new Vector3(w * u.x - w / , w * u.y - w / );
             vh.AddVert(uivertex);
         }
         //
         for (int i = ; i < segements + ; i++)
         {
             UIVertex uivertex = new UIVertex();
             uivertex.color = color;
             if (i == )
             {
                 uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (( - scale / ) + (scale / ) * Mathf.Sin(i *  / segements)), uv.y + (uv.w - uv.y) * (( - scale / ) + (scale / ) * Mathf.Cos(i *  / segements)));
                u = new Vector2(( - scale / ) + (scale / ) * Mathf.Sin(i *  / segements), ( - scale / ) + (scale / ) * Mathf.Cos(i *  / segements));
             }
             else
             {
                 uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (( - scale / ) + (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements)))), uv.y + (uv.w - uv.y) * (( - scale / ) + (scale / ) * Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))));
                 u= new Vector2(( - scale / ) + (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements))), ( - scale / ) + (scale / ) * Mathf.Cos(Mathf.PI / (180f / (i *  / segements))));
             }
             uivertex.position = new Vector3(w * u.x - w / , w * u.y - w / );
             vh.AddVert(uivertex);
         }
         //
         for (int i = ; i < segements + ; i++)
         {
             UIVertex uivertex = new UIVertex();
             uivertex.color = color;
             if (i == )
             {
                 uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (( - scale / ) + (scale / ) * Mathf.Cos(i *  / segements)), uv.y + (uv.w - uv.y) * ((scale / ) - (scale / ) * Mathf.Sin(i *  / segements)));
                 u  = new Vector2(( - scale / ) + (scale / ) * Mathf.Cos(i *  / segements), (scale / ) - (scale / ) * Mathf.Sin(i *  / segements));
             }
             else
             {
                 uivertex.uv0 = new Vector2(uv.x + (uv.z - uv.x) * (( - scale / ) + (scale / ) * Mathf.Cos(Mathf.PI / (180f / (i *  / segements)))), uv.y + (uv.w - uv.y) * ((scale / ) - (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements)))));
                 u = new Vector2(( - scale / ) + (scale / ) * Mathf.Cos(Mathf.PI / (180f / (i *  / segements))), (scale / ) - (scale / ) * Mathf.Sin(Mathf.PI / (180f / (i *  / segements))));
             }
             uivertex.position = new Vector3(w * u.x - w / , w * u.y - w / );
             vh.AddVert(uivertex);
         }

         //（（点*4+8个点-3）条弦+1）个三角形
         for (int i = ; i < ((segements - ) *  +  -  + ); i++)
         {
             vh.AddTriangle(, i + , i + );
         }
         #endregion
     }

     public override bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)
     {
 //        Sprite sprite = overrideSprite;
 //        if (sprite == null)
 //            return true;

     //    Debug.LogError("鼠标点击:" + screenPoint);

 //        Vector2 local;
 //        RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPoint, eventCamera, out local);
         return true;
     }

     private bool Contains(Vector2 p, List<Vector3> outterVertices, List<Vector3> innerVertices)
     {
         var crossNumber = ;
         RayCrossing(p, innerVertices, ref crossNumber);//检测内环
         RayCrossing(p, outterVertices, ref crossNumber);//检测外环
         return (crossNumber & ) == ;
     }

     /// <summary>
     /// 使用RayCrossing算法判断点击点是否在封闭多边形里
     /// </summary>
     /// <param name="p"></param>
     /// <param name="vertices"></param>
     /// <param name="crossNumber"></param>
     private void RayCrossing(Vector2 p, List<Vector3> vertices, ref int crossNumber)
     {
         for (int i = , count = vertices.Count; i < count; i++)
         {
             var v1 = vertices[i];
             var v2 = vertices[(i + ) % count];

             //点击点水平线必须与两顶点线段相交
             if (((v1.y <= p.y) && (v2.y > p.y))
                 || ((v1.y > p.y) && (v2.y <= p.y)))
             {
                 //只考虑点击点右侧方向，点击点水平线与线段相交，且交点x > 点击点x，则crossNumber+1
                 if (p.x < v1.x + (p.y - v1.y) / (v2.y - v1.y) * (v2.x - v1.x))
                 {
                     crossNumber += ;
                 }
             }
         }
     }

 }