Unity 截图选择框，中间全透明，边缘半透明
效果：点击白色框可拖拽选择区域
代码：
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems; public class jietu : MonoBehaviour, IDragHandler, IEndDragHandler,IBeginDragHandler
{
void Start()
{
//DrawTriangle(30, 0, 100, 250, 200, 100, mat);//三角形的三个定点坐标
} public void OnBeginDrag(PointerEventData eventData)
{
dragObj = eventData.rawPointerPress;
} public void OnDrag(PointerEventData eventData)
{
if (dragObj!=null)
{
dragObj.transform.position = Input.mousePosition; leftBottomPos = leftBottom.transform.position;
leftTopPos = leftTop.transform.position;
rightTopPos = rightTop.transform.position;
rightBottomPos = rightBottom.transform.position; if (dragObj.Equals(leftBottom))
{
leftTopPos.x = dragObj.transform.position.x;
rightBottomPos.y= dragObj.transform.position.y;
leftTop.transform.position = leftTopPos;
rightBottom.transform.position = rightBottomPos;
}
else if (dragObj.Equals(leftTop))
{
leftBottomPos.x = dragObj.transform.position.x;
rightTopPos.y = dragObj.transform.position.y;
leftBottom.transform.position = leftBottomPos;
rightTop.transform.position = rightTopPos;
}
else if (dragObj.Equals(rightTop))
{
rightBottomPos.x = dragObj.transform.position.x;
leftTopPos.y = dragObj.transform.position.y;
rightBottom.transform.position = rightBottomPos;
leftTop.transform.position = leftTopPos;
}
else if (dragObj.Equals(rightBottom))
{
rightTopPos.x = dragObj.transform.position.x;
leftBottomPos.y = dragObj.transform.position.y;
rightTop.transform.position = rightTopPos;
leftBottom.transform.position = leftBottomPos;
}
} } public void OnEndDrag(PointerEventData eventData)
{
dragObj = null;
} GameObject dragObj; public GameObject leftBottom;
public GameObject leftTop;
public GameObject rightTop;
public GameObject rightBottom; Vector2 leftBottomPos = Vector2.zero;
Vector2 leftTopPos = Vector2.zero;
Vector2 rightTopPos = Vector2.zero;
Vector2 rightBottomPos = Vector2.zero; public Material mat;
void OnRenderObject()
{
DrawTriangle();//三角形的三个定点坐标
}
void DrawTriangle()
{
GL.PushMatrix();
mat.SetPass(0);
GL.LoadOrtho();
GL.Begin(GL.QUADS);//顺时针方向 //顶部
GL.Vertex3(leftTop.transform.position.x / Screen.width, leftTop.transform.position.y / Screen.height, 0);
GL.Vertex3(0, 1, 0);
GL.Vertex3(1, 1, 0);
GL.Vertex3(rightTop.transform.position.x / Screen.width, rightTop.transform.position.y / Screen.height, 0); //右侧
GL.Vertex3(rightBottom.transform.position.x / Screen.width, rightBottom.transform.position.y / Screen.height, 0);
GL.Vertex3(rightTop.transform.position.x / Screen.width, rightTop.transform.position.y / Screen.height, 0);
GL.Vertex3(1, 1, 0);
GL.Vertex3(1, 0, 0); //底部
GL.Vertex3(0, 0, 0);//屏幕左下角
GL.Vertex3(leftBottom.transform.position.x / Screen.width, leftBottom.transform.position.y / Screen.height, 0);//屏幕左上角
GL.Vertex3(rightBottom.transform.position.x / Screen.width, rightBottom.transform.position.y / Screen.height, 0);//屏幕右上角
GL.Vertex3(1, 0, 0);//屏幕右下角 //左侧
GL.Vertex3(0, 0, 0);
GL.Vertex3(0, 1, 0);
GL.Vertex3(leftTop.transform.position.x / Screen.width, leftTop.transform.position.y / Screen.height, 0);
GL.Vertex3(leftBottom.transform.position.x / Screen.width, leftBottom.transform.position.y / Screen.height, 0); GL.End();
GL.PopMatrix();
}
}
unity里的设置
改良版：限定剪裁区域的最小范围
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems; public class jietu : MonoBehaviour, IDragHandler, IEndDragHandler, IBeginDragHandler
{
GameObject dragObj; public GameObject leftBottom;
public GameObject leftTop;
public GameObject rightTop;
public GameObject rightBottom; Vector2 leftBottomPos;
Vector2 leftTopPos;
Vector2 rightTopPos;
Vector2 rightBottomPos; public Material mat; public float x_min = 100;
public float y_min = 100; public void OnBeginDrag(PointerEventData eventData)
{
dragObj = eventData.rawPointerPress;
leftBottomPos = leftBottom.transform.position;
leftTopPos = leftTop.transform.position;
rightTopPos = rightTop.transform.position;
rightBottomPos = rightBottom.transform.position;
} public void OnDrag(PointerEventData eventData)
{
if (dragObj != null)
{
if (dragObj.Equals(leftBottom))
{
if ((rightTopPos.x - Input.mousePosition.x) > x_min)
{
leftBottomPos.x = Input.mousePosition.x;
leftTopPos.x = Input.mousePosition.x; leftBottom.transform.position = leftBottomPos;
leftTop.transform.position = leftTopPos;
} if ((rightTopPos.y - Input.mousePosition.y) > y_min)
{
leftBottomPos.y = Input.mousePosition.y;
rightBottomPos.y = Input.mousePosition.y; leftBottom.transform.position = leftBottomPos;
rightBottom.transform.position = rightBottomPos;
} }
else if (dragObj.Equals(leftTop))
{
if ((rightBottomPos.x - Input.mousePosition.x) > x_min)
{
leftTopPos.x = Input.mousePosition.x;
leftBottomPos.x = Input.mousePosition.x; leftTop.transform.position = leftTopPos;
leftBottom.transform.position = leftBottomPos; }
if ((Input.mousePosition.y - rightBottomPos.y) > y_min)
{
leftTopPos.y = Input.mousePosition.y;
rightTopPos.y = Input.mousePosition.y; leftTop.transform.position = leftTopPos;
rightTop.transform.position = rightTopPos;
}
}
else if (dragObj.Equals(rightTop))
{
if ((Input.mousePosition.x - leftBottomPos.x) > x_min)
{
rightTopPos.x = Input.mousePosition.x;
rightBottomPos.x = Input.mousePosition.x; rightTop.transform.position = rightTopPos;
rightBottom.transform.position = rightBottomPos;
}
if ((Input.mousePosition.y - leftBottomPos.y) > y_min)
{
rightTopPos.y = Input.mousePosition.y;
leftTopPos.y = Input.mousePosition.y; rightTop.transform.position = rightTopPos;
leftTop.transform.position = leftTopPos;
}
}
else if (dragObj.Equals(rightBottom))
{
if ((Input.mousePosition.x - leftTopPos.x) > x_min)
{
rightBottomPos.x = Input.mousePosition.x;
rightTopPos.x = Input.mousePosition.x; rightBottom.transform.position = rightBottomPos;
rightTop.transform.position = rightTopPos;
}
if ((leftTopPos.y - Input.mousePosition.y) > y_min)
{
rightBottomPos.y = Input.mousePosition.y;
leftBottomPos.y = Input.mousePosition.y; rightBottom.transform.position = rightBottomPos;
leftBottom.transform.position = leftBottomPos;
}
}
}
} public void OnEndDrag(PointerEventData eventData)
{
dragObj = null;
} void OnRenderObject()
{
DrawTriangle();//三角形的三个定点坐标
}
void DrawTriangle()
{
GL.PushMatrix();
mat.SetPass(0);
GL.LoadOrtho();
GL.Begin(GL.QUADS);//顺时针方向 //顶部
GL.Vertex3(leftTop.transform.position.x / Screen.width, leftTop.transform.position.y / Screen.height, 0);
GL.Vertex3(0, 1, 0);
GL.Vertex3(1, 1, 0);
GL.Vertex3(rightTop.transform.position.x / Screen.width, rightTop.transform.position.y / Screen.height, 0); //右侧
GL.Vertex3(rightBottom.transform.position.x / Screen.width, rightBottom.transform.position.y / Screen.height, 0);
GL.Vertex3(rightTop.transform.position.x / Screen.width, rightTop.transform.position.y / Screen.height, 0);
GL.Vertex3(1, 1, 0);
GL.Vertex3(1, 0, 0); //底部
GL.Vertex3(0, 0, 0);//屏幕左下角
GL.Vertex3(leftBottom.transform.position.x / Screen.width, leftBottom.transform.position.y / Screen.height, 0);//屏幕左上角
GL.Vertex3(rightBottom.transform.position.x / Screen.width, rightBottom.transform.position.y / Screen.height, 0);//屏幕右上角
GL.Vertex3(1, 0, 0);//屏幕右下角 //左侧
GL.Vertex3(0, 0, 0);
GL.Vertex3(0, 1, 0);
GL.Vertex3(leftTop.transform.position.x / Screen.width, leftTop.transform.position.y / Screen.height, 0);
GL.Vertex3(leftBottom.transform.position.x / Screen.width, leftBottom.transform.position.y / Screen.height, 0); GL.End();
GL.PopMatrix();
} }
在实际使用的时候发现用GL画的图像，会导致无法适应UGUI的层级关系，永远位于UI的下层或者上层（取决于Canvas的Render mode），
下面是改良版本，完美适应UI的层级关系
代码如下：
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.Serialization;
using UnityEngine.UI; public class LineChart : MaskableGraphic, IDragHandler, IEndDragHandler, IBeginDragHandler
{ protected override void OnPopulateMesh(VertexHelper vh)
{
vh.Clear(); UIVertex[] verts0 = new UIVertex[4]; //顶部
verts0[0]=SetVertexs(verts0[0], leftTop.transform.localPosition);
verts0[1]=SetVertexs(verts0[1], screen_leftTopPos);
verts0[2]=SetVertexs(verts0[2], screen_rightTopPos);
verts0[3] = SetVertexs(verts0[3], rightTop.transform.localPosition); vh.AddUIVertexQuad(verts0); UIVertex[] verts1 = new UIVertex[4];
//右侧
verts1[0] = SetVertexs(verts1[0], rightBottom.transform.localPosition);
verts1[1] = SetVertexs(verts1[1], rightTop.transform.localPosition);
verts1[2] = SetVertexs(verts1[2], screen_rightTopPos);
verts1[3] = SetVertexs(verts1[3], screen_rightBottomPos);
vh.AddUIVertexQuad(verts1); //底部
UIVertex[] verts2 = new UIVertex[4];
verts2[0] = SetVertexs(verts2[0], screen_leftBottomPos);//屏幕左下角
verts2[1] = SetVertexs(verts2[1], leftBottom.transform.localPosition);//屏幕左上角
verts2[2] = SetVertexs(verts2[2], rightBottom.transform.localPosition);//屏幕右上角
verts2[3] = SetVertexs(verts2[3], screen_rightBottomPos);//屏幕右下角
vh.AddUIVertexQuad(verts2); //左侧
UIVertex[] verts3 = new UIVertex[4];
verts3[0] = SetVertexs(verts3[0], screen_leftBottomPos);
verts3[1] = SetVertexs(verts3[1], screen_leftTopPos);
verts3[2] = SetVertexs(verts3[2], leftTop.transform.localPosition);
verts3[3] = SetVertexs(verts3[3], leftBottom.transform.localPosition);
vh.AddUIVertexQuad(verts3);
} GameObject dragObj; public GameObject leftBottom;
public GameObject leftTop;
public GameObject rightTop;
public GameObject rightBottom; Vector2 leftBottomPos;
Vector2 leftTopPos;
Vector2 rightTopPos;
Vector2 rightBottomPos; public float x_min = 100;
public float y_min = 100; readonly Vector2 screen_leftBottomPos= new Vector3(-Screen.width * 0.5f, -Screen.height * 0.5f);
readonly Vector2 screen_leftTopPos= new Vector3(-Screen.width * 0.5f, Screen.height * 0.5f);
readonly Vector2 screen_rightTopPos= new Vector3(Screen.width * 0.5f, Screen.height * 0.5f);
readonly Vector2 screen_rightBottomPos= new Vector3(Screen.width * 0.5f, -Screen.height * 0.5f); public void OnBeginDrag(PointerEventData eventData)
{
dragObj = eventData.rawPointerPress;
leftBottomPos = leftBottom.transform.localPosition;
leftTopPos = leftTop.transform.localPosition;
rightTopPos = rightTop.transform.localPosition;
rightBottomPos = rightBottom.transform.localPosition;
} public void OnDrag(PointerEventData eventData)
{
if (dragObj != null)
{
float x = Input.mousePosition.x - Screen.width * 0.5f;
float y = Input.mousePosition.y - Screen.height * 0.5f;
if (dragObj.Equals(leftBottom))
{
if ((rightTopPos.x - x) > x_min)
{
leftBottomPos.x = x;
leftTopPos.x = x; leftBottom.transform.localPosition = leftBottomPos;
leftTop.transform.localPosition = leftTopPos;
} if ((rightTopPos.y - y) > y_min)
{
leftBottomPos.y = y;
rightBottomPos.y = y; leftBottom.transform.localPosition = leftBottomPos;
rightBottom.transform.localPosition = rightBottomPos;
} }
else if (dragObj.Equals(leftTop))
{
if ((rightBottomPos.x - x) > x_min)
{
leftTopPos.x = x;
leftBottomPos.x = x; leftTop.transform.localPosition = leftTopPos;
leftBottom.transform.localPosition = leftBottomPos; }
if ((y - rightBottomPos.y) > y_min)
{
leftTopPos.y = y;
rightTopPos.y = y; leftTop.transform.localPosition = leftTopPos;
rightTop.transform.localPosition = rightTopPos;
}
}
else if (dragObj.Equals(rightTop))
{
if ((x - leftBottomPos.x) > x_min)
{
rightTopPos.x = x;
rightBottomPos.x = x; rightTop.transform.localPosition = rightTopPos;
rightBottom.transform.localPosition = rightBottomPos;
}
if ((y - leftBottomPos.y) > y_min)
{
rightTopPos.y = y;
leftTopPos.y = y; rightTop.transform.localPosition = rightTopPos;
leftTop.transform.localPosition = leftTopPos;
}
}
else if (dragObj.Equals(rightBottom))
{
if ((x - leftTopPos.x) > x_min)
{
rightBottomPos.x = x;
rightTopPos.x = x; rightBottom.transform.localPosition = rightBottomPos;
rightTop.transform.localPosition = rightTopPos;
}
if ((leftTopPos.y - y) > y_min)
{
rightBottomPos.y = y;
leftBottomPos.y = y; rightBottom.transform.localPosition = rightBottomPos;
leftBottom.transform.localPosition = leftBottomPos;
}
}
} UpdateGeometry();
} public void OnEndDrag(PointerEventData eventData)
{
dragObj = null;
} UIVertex SetVertexs(UIVertex vertex, Vector2 vertexPos)
{
vertex.position = vertexPos;
vertex.color = color;//color是父类中的属性
vertex.uv0 = Vector2.zero;
return vertex;
} }
最终版本：
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI; public class LineChart : Graphic, IDragHandler, IEndDragHandler, IBeginDragHandler
{
protected override void OnPopulateMesh(VertexHelper vh)
{
vh.Clear(); //顶部
verts0[0]=SetVertexs(verts0[0], leftTop.transform.localPosition);
verts0[1]=SetVertexs(verts0[1], screen_leftTopPos);
verts0[2]=SetVertexs(verts0[2], screen_rightTopPos);
verts0[3] = SetVertexs(verts0[3], rightTop.transform.localPosition);
vh.AddUIVertexQuad(verts0); //右侧
verts1[0] = SetVertexs(verts1[0], rightBottom.transform.localPosition);
verts1[1] = SetVertexs(verts1[1], rightTop.transform.localPosition);
verts1[2] = SetVertexs(verts1[2], screen_rightTopPos);
verts1[3] = SetVertexs(verts1[3], screen_rightBottomPos);
vh.AddUIVertexQuad(verts1); //底部
verts2[0] = SetVertexs(verts2[0], screen_leftBottomPos);//屏幕左下角
verts2[1] = SetVertexs(verts2[1], leftBottom.transform.localPosition);//屏幕左上角
verts2[2] = SetVertexs(verts2[2], rightBottom.transform.localPosition);//屏幕右上角
verts2[3] = SetVertexs(verts2[3], screen_rightBottomPos);//屏幕右下角
vh.AddUIVertexQuad(verts2); //左侧
verts3[0] = SetVertexs(verts3[0], screen_leftBottomPos);
verts3[1] = SetVertexs(verts3[1], screen_leftTopPos);
verts3[2] = SetVertexs(verts3[2], leftTop.transform.localPosition);
verts3[3] = SetVertexs(verts3[3], leftBottom.transform.localPosition);
vh.AddUIVertexQuad(verts3);
} public GameObject leftBottom;
public GameObject leftTop;
public GameObject rightTop;
public GameObject rightBottom; public float x_min = 100;
public float y_min = 100; GameObject dragObj; Vector2 leftBottomPos;
Vector2 leftTopPos;
Vector2 rightTopPos;
Vector2 rightBottomPos; readonly UIVertex[] verts0 = new UIVertex[4];
readonly UIVertex[] verts1 = new UIVertex[4];
readonly UIVertex[] verts2 = new UIVertex[4];
readonly UIVertex[] verts3 = new UIVertex[4]; readonly Vector2 screen_leftBottomPos= new Vector3(-Screen.width * 0.5f, -Screen.height * 0.5f);
readonly Vector2 screen_leftTopPos= new Vector3(-Screen.width * 0.5f, Screen.height * 0.5f);
readonly Vector2 screen_rightTopPos= new Vector3(Screen.width * 0.5f, Screen.height * 0.5f);
readonly Vector2 screen_rightBottomPos= new Vector3(Screen.width * 0.5f, -Screen.height * 0.5f); public void OnBeginDrag(PointerEventData eventData)
{
dragObj = eventData.rawPointerPress;
leftBottomPos = leftBottom.transform.localPosition;
leftTopPos = leftTop.transform.localPosition;
rightTopPos = rightTop.transform.localPosition;
rightBottomPos = rightBottom.transform.localPosition;
} public void OnDrag(PointerEventData eventData)
{
if (dragObj != null)
{
float x = Input.mousePosition.x - Screen.width * 0.5f;
float y = Input.mousePosition.y - Screen.height * 0.5f;
if (dragObj.Equals(leftBottom))
{
if ((rightTopPos.x - x) > x_min)
{
leftBottomPos.x = x;
leftTopPos.x = x; leftBottom.transform.localPosition = leftBottomPos;
leftTop.transform.localPosition = leftTopPos;
}
if ((rightTopPos.y - y) > y_min)
{
leftBottomPos.y = y;
rightBottomPos.y = y; leftBottom.transform.localPosition = leftBottomPos;
rightBottom.transform.localPosition = rightBottomPos;
}
}
else if (dragObj.Equals(leftTop))
{
if ((rightBottomPos.x - x) > x_min)
{
leftTopPos.x = x;
leftBottomPos.x = x; leftTop.transform.localPosition = leftTopPos;
leftBottom.transform.localPosition = leftBottomPos; }
if ((y - rightBottomPos.y) > y_min)
{
leftTopPos.y = y;
rightTopPos.y = y; leftTop.transform.localPosition = leftTopPos;
rightTop.transform.localPosition = rightTopPos;
}
}
else if (dragObj.Equals(rightTop))
{
if ((x - leftBottomPos.x) > x_min)
{
rightTopPos.x = x;
rightBottomPos.x = x; rightTop.transform.localPosition = rightTopPos;
rightBottom.transform.localPosition = rightBottomPos;
}
if ((y - leftBottomPos.y) > y_min)
{
rightTopPos.y = y;
leftTopPos.y = y; rightTop.transform.localPosition = rightTopPos;
leftTop.transform.localPosition = leftTopPos;
}
}
else if (dragObj.Equals(rightBottom))
{
if ((x - leftTopPos.x) > x_min)
{
rightBottomPos.x = x;
rightTopPos.x = x; rightBottom.transform.localPosition = rightBottomPos;
rightTop.transform.localPosition = rightTopPos;
}
if ((leftTopPos.y - y) > y_min)
{
rightBottomPos.y = y;
leftBottomPos.y = y; rightBottom.transform.localPosition = rightBottomPos;
leftBottom.transform.localPosition = leftBottomPos;
}
}
}
UpdateGeometry();
} public void OnEndDrag(PointerEventData eventData)
{
dragObj = null;
} UIVertex SetVertexs(UIVertex vertex, Vector2 vertexPos)
{
vertex.position = vertexPos;
vertex.color = color;//color是父类中的属性
vertex.uv0 = Vector2.zero;
return vertex;
}
}
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