重写了一个image组件，将精灵拖进去可调整圆角的大小和平滑度，我写的这个只支持正方形图片，矩形会比较麻烦，暂时还没想到方法
实现思路:
1.如下图，image画图原理就是在一个方框中画三角形，然后形成图片，红线代表方框的坐标系，蓝色代表图片的坐标系，也就是你在这个方框的某个位置上画图片的哪个部位，例如蓝色的（0,0）点，假如image宽度，高度都为2，也就是在黑框的（-1，-1）画一个（0,0）点。
2.如果想要圆角就很简单了，就是在角上多画几个间距相等的点，点越多平滑度越高，例如我图中左上角多加了一个点，四边形也就成了五边形，得到5个点的集合，也就是图中的紫色数字。
3.画图是由很多个三角形构成，（注意添加三角形时，点的方向必须是顺时针的，例如（0,1,2），（2,3,4）,（4，5，0）都可以），然后就可以用一个for循环，从0点开始添加三角形（i，i+1，i+2）。添加完成后图也就画好了~~~^_^~~~
4.点的位置，用sin和cos（90/（点的个数）)*r（如果想画圆形r就是1/2）得到点在蓝色坐标的位置，红色坐标可以根据蓝色坐标得到，他两关系是固定的嘛。根据宽度得就行（ps：蓝色坐标中，图片的长宽都为1，而红色的是根据image实际的width和height）
1 using System.Collections.Generic;
2 using UnityEngine;
3 using UnityEngine.UI;
4 using UnityEngine.Sprites;
5
6 [AddComponentMenu("UI/Circle Image")]
7 public class CircleImage2 : BaseImage {
8
9 // Use this for initialization
10 void Awake () {
11 innerVertices = new List<Vector3>();
12 outterVertices = new List<Vector3>();
13 }
14
15 // Update is called once per frame
16 void Update () {
17
18 }
19
20
21 [Range(0, 1)]
22 public float scale = 1f;
23
24 [Range(2, 30)]
25 public int segements = 2;
26
27 private List<Vector3> innerVertices;
28 private List<Vector3> outterVertices;
29
30 protected override void OnPopulateMesh(VertexHelper vh)
31 {
32 vh.Clear();
33 Rect pixelAdjustedRect = this.GetPixelAdjustedRect();
34
35 float w = pixelAdjustedRect.width;
36 for (int i =0; i < segements+1; i++)
37 {
38 UIVertex uivertex = new UIVertex();
39 uivertex.color = color;
40 if (i ==0)
41 {
42 uivertex.uv0 = new Vector2((scale / 2) * (1 - Mathf.Sin(i * 90 / segements)),(scale / 2) * (1 - Mathf.Cos(i * 90 / segements)));
43 }
44 else
45 {
46 uivertex.uv0 = new Vector2((scale / 2) * (1 - Mathf.Sin(Mathf.PI / (180f /(i * 90 / segements)))), (scale / 2) * (1 - Mathf.Cos(Mathf.PI / (180f / (i * 90 / segements)))));
47 }
48 uivertex.position = new Vector3(w*uivertex.uv0.x-w/2,w*uivertex.uv0.y-w/2);
49
50 vh.AddVert(uivertex);
51 }
52
53 for (int i = 0; i < segements + 1; i++)
54 {
55 UIVertex uivertex = new UIVertex();
56 uivertex.color = color;
57 if (i == 0)
58 {
59 uivertex.uv0 = new Vector2((scale / 2) - (scale / 2) * Mathf.Cos(i * 90 / segements), (1 - scale / 2) + (scale / 2) * Mathf.Sin(i * 90 / segements));
60 }
61 else
62 {
63 uivertex.uv0 = new Vector2((scale / 2) * (1 - Mathf.Cos(Mathf.PI / (180f / (i * 90 / segements)))), (1 - scale / 2) + (scale / 2) * Mathf.Sin(Mathf.PI / (180f / (i * 90 / segements))));
64 }
65 uivertex.position = new Vector3(w * uivertex.uv0.x - w / 2, w * uivertex.uv0.y - w / 2);
66 vh.AddVert(uivertex);
67 }
68
69 for (int i = 0; i < segements + 1; i++)
70 {
71 UIVertex uivertex = new UIVertex();
72 uivertex.color = color;
73 if (i == 0)
74 {
75 uivertex.uv0 = new Vector2((1 - scale / 2) + (scale / 2) * Mathf.Sin(i * 90 / segements), (1 - scale / 2) + (scale / 2) * Mathf.Cos(i * 90 / segements));
76 }
77 else
78 {
79 uivertex.uv0 = new Vector2( (1 - scale / 2) + (scale / 2) * Mathf.Sin(Mathf.PI / (180f / (i * 90 / segements))), (1 - scale / 2) + (scale / 2) * Mathf.Cos(Mathf.PI / (180f / (i * 90 / segements))));
80
81 }
82 uivertex.position = new Vector3(w * uivertex.uv0.x - w / 2, w * uivertex.uv0.y - w / 2);
83 vh.AddVert(uivertex);
84 }
85 for (int i = 0; i < segements + 1; i++)
86 {
87 UIVertex uivertex = new UIVertex();
88 uivertex.color = color;
89 if (i == 0)
90 {
91 uivertex.uv0 = new Vector2((1 - scale / 2) + (scale / 2) * Mathf.Cos(i * 90 / segements), (scale / 2) - (scale / 2) * Mathf.Sin(i * 90 / segements));
92 }
93 else
94 {
95 uivertex.uv0 = new Vector2((1 - scale / 2) + (scale / 2) * Mathf.Cos(Mathf.PI / (180f / (i * 90 / segements))), (scale / 2) - (scale / 2) * Mathf.Sin(Mathf.PI / (180f / (i * 90 / segements))));
96 }
97 uivertex.position = new Vector3(w * uivertex.uv0.x - w / 2, w * uivertex.uv0.y - w / 2);
98 vh.AddVert(uivertex);
99 }
100
101 //（（点*4+8个点-3）条弦+1）个三角形
102 for (int i = 0; i < ((segements - 1) * 4 + 8 - 3 + 1); i++)
103 {
104 vh.AddTriangle(0, i + 1, i + 2);
105 }
106
107
108 }
109
110 public override bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)
111 {
112 Sprite sprite = overrideSprite;
113 if (sprite == null)
114 return true;
115
116 Vector2 local;
117 RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPoint, eventCamera, out local);
118 return Contains(local, outterVertices, innerVertices);
119 }
120
121 private bool Contains(Vector2 p, List<Vector3> outterVertices, List<Vector3> innerVertices)
122 {
123 var crossNumber = 0;
124 RayCrossing(p, innerVertices, ref crossNumber);//检测内环
125 RayCrossing(p, outterVertices, ref crossNumber);//检测外环
126 return (crossNumber & 1) == 1;
127 }
128
129 /// <summary>
130 /// 使用RayCrossing算法判断点击点是否在封闭多边形里
131 /// </summary>
132 /// <param name="p"></param>
133 /// <param name="vertices"></param>
134 /// <param name="crossNumber"></param>
135 private void RayCrossing(Vector2 p, List<Vector3> vertices, ref int crossNumber)
136 {
137 for (int i = 0, count = vertices.Count; i < count; i++)
138 {
139 var v1 = vertices[i];
140 var v2 = vertices[(i + 1) % count];
141
142 //点击点水平线必须与两顶点线段相交
143 if (((v1.y <= p.y) && (v2.y > p.y))
144 || ((v1.y > p.y) && (v2.y <= p.y)))
145 {
146 //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
147 if (p.x < v1.x + (p.y - v1.y) / (v2.y - v1.y) * (v2.x - v1.x))
148 {
149 crossNumber += 1;
150 }
151 }
152 }
153 }
154
155
156 }
时间： 2024-08-07 01:02:43