孙广东   2016.10.15

http://blog.csdn.net/u010019717

起这个标题完全是为了区分于 《Unity 关于UGUI不规则图片响应区域解决方法》

最近看到 《Unity 关于NGUI不规则图片响应区域解决方法》    之所以要记录这个也是多自己之前项目的一个总结， 看看那里不好， 该怎么解决！。  我们卡牌游戏就是 UGUI + spine

推荐  雨凇的（看一下评论）

UGUI研究院之不规则按钮的响应区域（十四）

来自 <http://www.xuanyusong.com/archives/3492>

非常巧妙 使用  Polygon Collider2D 作为区域编辑和判断， 但是不能跟随图片的分辨率变化！  这是硬伤！

而且代码可以简化使用  Collider2D.OverlapPoint    判断点在没在多边形碰撞体中

推荐  秦元培 的总结（多边形碰撞器<还是  雨凇  的> 和  精灵像素检测  <出处 http://m.manew.com/forum.php?mod=viewthread&tid=45046&highlight=uGUI%2B%E4%B8%8D%E8%A7%84%E5%88%99&mobile=2 >）

Unity3D游戏开发之在uGUI中使用不规则精灵制作按钮

来自 <http://blog.csdn.net/qinyuanpei/article/details/51868638>

首先指出雨凇的代码实现问题（判断一个点在没在多边形内的算法 http://geomalgorithms.com/a03-_inclusion.html ）。     同时也说明了 Image.eventAlphaThreshold  的 意义用处！

 开始正题吧

扩展  UGUI组件呗！

1、自己设置多边形组件（判断一个点是否在一个多边形内）。  2、就是镂空精灵（透明度）。  首先为什么要有第一种需求， 我们游戏当时使用的是Spine动画， 不是精灵， 所以当时用的 2d碰撞体。 如果用镂空精灵作为检测区域的话，就会增加游戏无用的资源， 因为不参与显示（显示的是spine动画）。所以就有了需求1.               对于2、镂空精灵， 就是 秦元培  他们网上所说的方式！也是需要Sprite资源的！

主要是根据IsRaycastLocationValid这个方法的返回值来进行判断的，而这个方法用到的基本原理则是判断指定点对应像素的RGBA数值中的Alpha是否大于某个指定临界值。

而且

public override boolIsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera)

{

//当透明度>=1.0时，表示点击在可响应区域返回true

if (m_EventAlphaThreshold >= 1)

return true;

//当没有指定精灵时为什么要返回true?

Debug.Log("射线检测");

Sprite sprite = overrideSprite;

if (sprite == null)      //  注意这个，如果要想像素检测这个不能为空！， 编辑器一定要赋值一个内容

return true;

1、自己设置多边形组件

参考 我之前的博客： 《Unity游戏选/创建角色界面中职业能力图六角形》     来自 <http://blog.csdn.net/u010019717/article/details/52279010>

中的   脚本  UIPolygon.cs

我的想法是错的，  我没有办法得到    最终显示的渲染状态（颜色表）。     也就没办法脱离  贴图  做判断！， 唉~

还好想到了           Mesh能得到顶点数，  能得到三角形，判断在没在多边形内， 所有三角形内就可以了！！！！！！！！     哈哈~

using UnityEngine;
using System.Collections.Generic;
using UnityEngine.UI;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.Assertions.Must;
using UnityEngine.UI.Extensions;namespace SGD
{/// <summary>/// 描述：/// author： sunguangdong/// </summary>[AddComponentMenu("SGD/PolygonButtonWithPixel")]public class PolygonButtonWithPixel : UIPrimitiveBase, IPointerClickHandler{public bool fill = true;public float thickness = 5;[Range(3, 360)]public int sides = 3;[Range(0, 360)]public float rotation = 0;[Range(0, 1)]public float[] VerticesDistances = new float[3];private float size = 0;/// /       针对 多边形响应区域检测  startpublic bool _isShowUI;public UnityEvent _ClickEvent = new UnityEvent();public void Start(){useLegacyMeshGeneration = false;}public void OnPointerClick(PointerEventData eventData){Debug.LogError("点击到精灵");_ClickEvent.Invoke();}/ <summary>/ 只参与 点击响应， 不参与绘制   todo 但是在编辑器下也看不到了？？？？？/ </summary>/ <param name="toFill"></param>//protected override void OnPopulateMesh(VertexHelper toFill)//{//    toFill.Clear();//}/// <summary>/// 自定义 多边形响应区域（根据Mesh内的顶点 和 三角形弄的）/// </summary>/// <param name="screenPoint"></param>/// <param name="eventCamera"></param>/// <returns></returns>public override bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera){Vector2 local;RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPoint, eventCamera, out local);try{return InPolygon(new Vector3(local.x, local.y, 0));}catch (UnityException e){Debug.LogError("Using clickAlphaThreshold lower than 1 on Image whose sprite texture cannot be read. " + e.Message + " Also make sure to disable sprite packing for this sprite.", this);return true;}}/// <summary>///  判断一个点  在没在多边形内！/// </summary>/// <param name="_target"></param>/// <returns></returns>protected bool InPolygon(Vector3 _target){Vector2 prevX = Vector2.zero;Vector2 prevY = Vector2.zero;Vector2 pos0;Vector2 pos1;Vector2 pos2;float degrees = 360f / sides;int vertices = sides + 1;if (VerticesDistances.Length != vertices){VerticesDistances = new float[vertices];for (int i = 0; i < vertices - 1; i++) VerticesDistances[i] = 1;}// last vertex is also the first!VerticesDistances[vertices - 1] = VerticesDistances[0];for (int i = 0; i < vertices; i++){float outer = -rectTransform.pivot.x * size * VerticesDistances[i];float inner = -rectTransform.pivot.x * size * VerticesDistances[i] + thickness;float rad = Mathf.Deg2Rad * (i * degrees + rotation);float c = Mathf.Cos(rad);float s = Mathf.Sin(rad);pos0 = prevX;pos1 = new Vector2(outer * c, outer * s);if (fill){pos2 = Vector2.zero;}else{pos2 = new Vector2(inner * c, inner * s);}prevX = pos1;prevY = pos2;if (InTrigon(_target, pos0, pos1, pos2)){return true;}}return false;}/// <summary>///  判断一个点  在没在三角形内！/// </summary>/// <param name="_target"></param>/// <param name="_center"></param>/// <param name="_left"></param>/// <param name="_right"></param>/// <returns></returns>public static bool InTrigon(Vector3 _target, Vector3 _center, Vector3 _left, Vector3 _right){Debug.Log(_target.ToString() + _center.ToString() + _left.ToString() + _right.ToString());Vector3 Ctl = _left - _center;Vector3 Ctr = _right - _center;Vector3 Ctt = _target - _center;Vector3 Ltr = _right - _left;Vector3 Ltc = _right - _center;Vector3 Ltt = _left - _target;Vector3 Rtl = _left - _right;Vector3 Rtc = _center - _right;Vector3 Rtt = _target - _right;if (Vector3.Dot(Vector3.Cross(Ctl, Ctr).normalized, Vector3.Cross(Ctl, Ctt).normalized) == 1 &&Vector3.Dot(Vector3.Cross(Ltr, Ltc).normalized, Vector3.Cross(Ltr, Ltt).normalized) == 1 &&Vector3.Dot(Vector3.Cross(Rtc, Rtl).normalized, Vector3.Cross(Rtc, Rtt).normalized) == 1)return true;elsereturn false;}///  /       针对 多边形响应区域检测  endpublic void DrawPolygon(int _sides){sides = _sides;VerticesDistances = new float[_sides + 1];for (int i = 0; i < _sides; i++) VerticesDistances[i] = 1; ;rotation = 0;}public void DrawPolygon(int _sides, float[] _VerticesDistances){sides = _sides;VerticesDistances = _VerticesDistances;rotation = 0;}public void DrawPolygon(int _sides, float[] _VerticesDistances, float _rotation){sides = _sides;VerticesDistances = _VerticesDistances;rotation = _rotation;}void Update(){size = rectTransform.rect.width;if (rectTransform.rect.width > rectTransform.rect.height)size = rectTransform.rect.height;elsesize = rectTransform.rect.width;thickness = (float)Mathf.Clamp(thickness, 0, size / 2);}protected override void OnPopulateMesh(VertexHelper vh){vh.Clear();if (_isShowUI){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 degrees = 360f / sides;int vertices = sides + 1;if (VerticesDistances.Length != vertices){VerticesDistances = new float[vertices];for (int i = 0; i < vertices - 1; i++) VerticesDistances[i] = 1;}// last vertex is also the first!VerticesDistances[vertices - 1] = VerticesDistances[0];for (int i = 0; i < vertices; i++){float outer = -rectTransform.pivot.x * size * VerticesDistances[i];float inner = -rectTransform.pivot.x * size * VerticesDistances[i] + thickness;float rad = Mathf.Deg2Rad * (i * degrees + rotation);float c = Mathf.Cos(rad);float s = Mathf.Sin(rad);uv0 = new Vector2(0, 1);uv1 = new Vector2(1, 1);uv2 = new Vector2(1, 0);uv3 = new Vector2(0, 0);pos0 = prevX;pos1 = new Vector2(outer * c, outer * s);if (fill){pos2 = Vector2.zero;pos3 = Vector2.zero;}else{pos2 = new Vector2(inner * c, inner * s);pos3 = prevY;}prevX = pos1;prevY = pos2;vh.AddUIVertexQuad(SetVbo(new[] { pos0, pos1, pos2, pos3 }, new[] { uv0, uv1, uv2, uv3 }));}}}}
}

using System;namespace UnityEngine.UI.Extensions
{public class UIPrimitiveBase : MaskableGraphic, ILayoutElement, ICanvasRaycastFilter{[SerializeField]private Sprite m_Sprite;public Sprite sprite { get { return m_Sprite; } set { if (SetPropertyUtility.SetClass(ref m_Sprite, value)) SetAllDirty(); } }[NonSerialized]private Sprite m_OverrideSprite;public Sprite overrideSprite { get { return m_OverrideSprite == null ? sprite : m_OverrideSprite; } set { if (SetPropertyUtility.SetClass(ref m_OverrideSprite, value)) SetAllDirty(); } }// Not serialized until we support read-enabled sprites better.internal float m_EventAlphaThreshold = 1;public float eventAlphaThreshold { get { return m_EventAlphaThreshold; } set { m_EventAlphaThreshold = value; } }/// <summary>/// Image's texture comes from the UnityEngine.Image./// </summary>public override Texture mainTexture{get{if (overrideSprite == null){if (material != null && material.mainTexture != null){return material.mainTexture;}return s_WhiteTexture;}return overrideSprite.texture;}}public float pixelsPerUnit{get{float spritePixelsPerUnit = 100;if (sprite)spritePixelsPerUnit = sprite.pixelsPerUnit;float referencePixelsPerUnit = 100;if (canvas)referencePixelsPerUnit = canvas.referencePixelsPerUnit;return spritePixelsPerUnit / referencePixelsPerUnit;}}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;}#region ILayoutElement Interfacepublic virtual void CalculateLayoutInputHorizontal() { }public virtual void CalculateLayoutInputVertical() { }public virtual float minWidth { get { return 0; } }public virtual float preferredWidth{get{if (overrideSprite == null)return 0;return overrideSprite.rect.size.x / pixelsPerUnit;}}public virtual float flexibleWidth { get { return -1; } }public virtual float minHeight { get { return 0; } }public virtual float preferredHeight{get{if (overrideSprite == null)return 0;return overrideSprite.rect.size.y / pixelsPerUnit;}}public virtual float flexibleHeight { get { return -1; } }public virtual int layoutPriority { get { return 0; } }#endregion#region ICanvasRaycastFilter Interfacepublic virtual bool IsRaycastLocationValid(Vector2 screenPoint, Camera eventCamera){if (m_EventAlphaThreshold >= 1)return true;Sprite sprite = overrideSprite;if (sprite == null)return true;Vector2 local;RectTransformUtility.ScreenPointToLocalPointInRectangle(rectTransform, screenPoint, eventCamera, out local);Rect rect = GetPixelAdjustedRect();// Convert to have lower left corner as reference point.local.x += rectTransform.pivot.x * rect.width;local.y += rectTransform.pivot.y * rect.height;local = MapCoordinate(local, rect);// Normalize local coordinates.Rect spriteRect = sprite.textureRect;Vector2 normalized = new Vector2(local.x / spriteRect.width, local.y / spriteRect.height);// Convert to texture space.float x = Mathf.Lerp(spriteRect.x, spriteRect.xMax, normalized.x) / sprite.texture.width;float y = Mathf.Lerp(spriteRect.y, spriteRect.yMax, normalized.y) / sprite.texture.height;try{return sprite.texture.GetPixelBilinear(x, y).a >= m_EventAlphaThreshold;}catch (UnityException e){Debug.LogError("Using clickAlphaThreshold lower than 1 on Image whose sprite texture cannot be read. " + e.Message + " Also make sure to disable sprite packing for this sprite.", this);return true;}}/// <summary>/// Return image adjusted position/// **Copied from Unity's Image component for now and simplified for UI Extensions primatives/// </summary>/// <param name="local"></param>/// <param name="rect"></param>/// <returns></returns>private Vector2 MapCoordinate(Vector2 local, Rect rect){Rect spriteRect = sprite.rect;return new Vector2(local.x * spriteRect.width / rect.width, local.y * spriteRect.height / rect.height);}Vector4 GetAdjustedBorders(Vector4 border, Rect rect){for (int axis = 0; axis <= 1; axis++){float combinedBorders = border[axis] + border[axis + 2];if (rect.size[axis] < combinedBorders && combinedBorders != 0){float borderScaleRatio = rect.size[axis] / combinedBorders;border[axis] *= borderScaleRatio;border[axis + 2] *= borderScaleRatio;}}return border;}#endregion}
}

其中要说明的    1、  是否参与绘制 _isShowUI  （只是接受检测，涉及到填充率, 在编辑器下编辑完多边形测试OK，就设置为false） 。   2、算法不涉及到  镂空精灵的算法，所以可以设置Sprite属性。

2、镂空精灵

镂空就是  透明的区域不接受检测，不透明区域接受检测。  透明不透明的指标自己定吧！

using UnityEngine;
using System.Collections.Generic;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using UnityEngine.Assertions.Must;namespace SGD
{/// <summary>/// 描述：/// author： sunguangdong/// </summary>[AddComponentMenu("SGD/UnregularButtonWithPixel ")][RequireComponent(typeof(Image))]public class UnregularButtonWithPixel : MonoBehaviour, IPointerClickHandler{/// <summary>/// Image组件/// </summary>private Image _image;/// <summary>/// 透明度临界值/// </summary>[Range(0.0f, 0.5f)]public float _Alpha;// 编辑器脚本 startvoid Reset(){_image = transform.GetComponent<Image>();}public void OnValidate(){MustExtensions.MustBeFalse(!_image , "UnregularButtonWithPixel 脚本的 Inspector 面板的赋值 不全！");}// 编辑器脚本 end public void Start(){//获取Image组件_image = transform.GetComponent<Image>();//设定透明度临界值_image.eventAlphaThreshold = _Alpha;}public void OnPointerClick(PointerEventData eventData){Debug.Log("点击到精灵");}}
}

Canvas 下的空对象上  添加这个组件  测试

提醒，  检测的开关还有  （这两种方式  都会受到  下面的开关影响！）