转载-UGUI中RawImage显示多边形或者圆形

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
 
public class UICircle : RawImage
{
    const int FILL_PERCENT = 100;
    float thickness = 5;
 
    [SerializeField][Range(4,360)]
    int _segments = 36;
	
    public int segments
    {
        get
        {
            return _segments;
        }
        set
        {
            if (_segments != value)
            {
                _segments = value;
                SetVerticesDirty();
                #if UNITY_EDITOR
                UnityEditor.EditorUtility.SetDirty(transform);
                #endif
            }
        }
    }
 
    protected override void OnRectTransformDimensionsChange()
    {
        base.OnRectTransformDimensionsChange();
        this.thickness = (float)Mathf.Clamp(this.thickness, 0, rectTransform.rect.width / 2);
    }
 
    protected override void OnPopulateMesh(VertexHelper vh)
    {
        float outer = -rectTransform.pivot.x * rectTransform.rect.width;
        float inner = -rectTransform.pivot.x * rectTransform.rect.width + this.thickness;
 
        vh.Clear();
 
        Vector2 prevX = Vector2.zero;
        Vector2 prevY = Vector2.zero;
        Vector2 uv0 = new Vector2(0, 0);
        Vector2 uv1 = new Vector2(0, 1);
        Vector2 uv2 = new Vector2(1, 1);
        Vector2 uv3 = new Vector2(1, 0);
        Vector2 pos0;
        Vector2 pos1;
        Vector2 pos2;
        Vector2 pos3;
 
        float tw = rectTransform.rect.width;
        float th = rectTransform.rect.height;
 
        float angleByStep = (FILL_PERCENT / 100f * (Mathf.PI * 2f)) / segments;
        float currentAngle = 0f;
        for (int i = 0; i < segments + 1; i++)
        {
 
            float c = Mathf.Cos(currentAngle);
            float s = Mathf.Sin(currentAngle);
 
            StepThroughPointsAndFill(outer, inner, ref prevX, ref prevY, out pos0, out pos1, out pos2, out pos3, c, s);
 
            uv0 = new Vector2(pos0.x / tw + 0.5f, pos0.y / th + 0.5f);
            uv1 = new Vector2(pos1.x / tw + 0.5f, pos1.y / th + 0.5f);
            uv2 = new Vector2(pos2.x / tw + 0.5f, pos2.y / th + 0.5f);
            uv3 = new Vector2(pos3.x / tw + 0.5f, pos3.y / th + 0.5f);
 
            vh.AddUIVertexQuad(SetVbo(new[] { pos0, pos1, pos2, pos3 }, new[] { uv0, uv1, uv2, uv3 }));
 
            currentAngle += angleByStep;
        }
    }
 
    private void StepThroughPointsAndFill(float outer, float inner, ref Vector2 prevX, ref Vector2 prevY, out Vector2 pos0, out Vector2 pos1, out Vector2 pos2, out Vector2 pos3, float c, float s)
    {
        pos0 = prevX;
        pos1 = new Vector2(outer * c, outer * s);
 
        pos2 = Vector2.zero;
        pos3 = Vector2.zero;
 
        prevX = pos1;
        prevY = pos2;
    }
 
    protected UIVertex[] SetVbo(Vector2[] vertices, Vector2[] uvs)
    {
        UIVertex[] vbo = new UIVertex[4];
        for (int i = 0; i < vertices.Length; i++)
        {
            var vert = UIVertex.simpleVert;
            vert.color = color;
            vert.position = vertices[i];
            vert.uv0 = uvs[i];
            vbo[i] = vert;
        }
        return vbo;
    }
 
}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using UnityEditor.UI;
 
[CustomEditor(typeof(UICircle), true)]
[CanEditMultipleObjects]
public class UICircleInspector : RawImageEditor
{
 
    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();
        UICircle circle = target as UICircle;
        circle.segments = Mathf.Clamp(EditorGUILayout.IntField("UICircle多边形", circle.segments), 4, 360);
 
    }
 
}