在Unity中绘制UGUI曲线图

之前一直使用的Xchart图表,只是在项目里遇到了奇怪的BUG,没办法只能自己写一个
首先是封装一个贝塞尔曲线,这里要用三次贝塞尔,两次不行

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


public class BezierMath
{
    /// 

    /// 二次贝塞尔曲线
    /// 
    /// 
    /// 
    /// 
    /// 
    /// 
    public static Vector3 Bezier_2(Vector3 p0, Vector3 p1, Vector3 p2, float t)
    {
        return (1 - t) * ((1 - t) * p0 + t * p1) + t * ((1 - t) * p1 + t * p2);
    }
    public static void Bezier_2ref(ref Vector3 outValue, Vector3 p0, Vector3 p1, Vector3 p2, float t)
    {
        outValue = (1 - t) * ((1 - t) * p0 + t * p1) + t * ((1 - t) * p1 + t * p2);
    }

    /// 

    /// 三次贝塞尔
    /// 
    public static Vector3 Bezier_3(Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
    {
        return (1 - t) * ((1 - t) * ((1 - t) * p0 + t * p1) + t * ((1 - t) * p1 + t * p2)) + t * ((1 - t) * ((1 - t) * p1 + t * p2) + t * ((1 - t) * p2 + t * p3));
    }
    public static void Bezier_3ref(ref Vector3 outValue, Vector3 p0, Vector3 p1, Vector3 p2, Vector3 p3, float t)
    {
        outValue = (1 - t) * ((1 - t) * ((1 - t) * p0 + t * p1) + t * ((1 - t) * p1 + t * p2)) + t * ((1 - t) * ((1 - t) * p1 + t * p2) + t * ((1 - t) * p2 + t * p3));
    }
}

然后就是继承basemesheffect,对image进行绘制,三角形的点与三角形绘制顺序对应好就可以了.
先画线段,线段之间友丰,然后用三角形把缝补上,最后再渐变填充
贝塞尔曲线的控制点位置注意下,让上一段线的控制点二与下一段线的控制点一与两控制点中间的点相切就可以了

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
[RequireComponent(typeof(Image))]
[ExecuteInEditMode]
public class MyLineChart : BaseMeshEffect
{
    public Image image;
    [Tooltip("设定值")]
    /// 

    /// 设定值
    /// 
    public List<float> valueList = new List<float>();
    [Tooltip("两值的间隔")]
    /// 

    /// 两值的间隔
    /// 
    public float valueInternal = 1;
    /// 

    /// 幅度
    /// 
    [Tooltip("振幅")]
    public float amplitude = 1;
    [Tooltip("采样密度")]
    /// 

    /// 贝塞尔点的密度
    /// 
    [Range(5,100)]
    public int density = 10;

    /// 

    /// 线宽
    /// 
    public float lineWidth = 1;
    /// 

    /// 最高点
    /// 
    public float heightPos;


    [Tooltip("线的颜色")]
    public Color lineColor = Color.white;
    [Tooltip("填充颜色0")]
    public Color fillColor0 = Color.white;
    [Tooltip("填充颜色1")]
    public Color fillColor1 = Color.white;
    [Tooltip("是否填充面积颜色")]
    public bool fillAreaColor;


   



    private List<Vector2> points = new List<Vector2>();
    /// 

    /// 两点之间的定位点
    /// 
    private List<Vector2> controlPointList = new List<Vector2>();
    //计算出的点放这里
    private List<Vector3> resList = new List<Vector3>();
    /// 

    /// 矩形的四角的点
    /// 
    private List<Vector3> quadAnchorList = new List<Vector3>();

    protected override void Awake()
    {
        if(image==null)
        {
                image = GetComponent<Image>();
        }
    }

    private void Update()
    {
       
        
        image.SetVerticesDirty();
    }
    public override void ModifyMesh(VertexHelper vh)
    {
        vh.Clear();
        points.Clear();
        quadAnchorList.Clear();
        heightPos = 0;


        for(int i= 0;i<valueList.Count;i++)
        {
            points.Add(new Vector2(i * valueInternal, valueList[i]*amplitude));
            //当前值大于最高值就替换
            if(valueList[i] * amplitude>heightPos)
            {
                heightPos = valueList[i] * amplitude;
            }
        }



        resList.Clear();
        controlPointList.Clear();

        for(int i=0;i<points.Count-1;i++)
        {
            //先取两点中间点
            controlPointList.Add(new Vector2((points[i] + points[i + 1]).x / 2, points[i].y));
            controlPointList.Add(new Vector2((points[i] + points[i + 1]).x / 2,points[i+1].y));
           
        }



       



        for(int i = 0;i<points.Count-1;i++)
        {
            //todo:用三阶贝塞尔曲线,不然结果是奇怪的波形
            //设定贝塞尔曲线采样密度
            for(int j =0;j<density;j++)
            {
                resList.Add(BezierMath.Bezier_3(points[i], controlPointList[i*2],controlPointList[i*2+1], points[i+1], j * (1/(float)density)));
            }
        }
        resList.Add(points[points.Count - 1]);


        for (int i=0;i<resList.Count-1;i++)
        {
            DrawQuad(vh, resList[i], resList[i+1], i);
        }
        DrawTriangle(vh);
        FillAreaColor(vh);
       
       


    }


    /// 

    /// 设置数据
    /// 
    public void SetData(List<float> val)
    {
        valueList = val;
    }

    /// 

    /// 画方块,给两点位置,同时给startindex的序号
    /// 
    public void DrawQuad(VertexHelper vh,Vector2 startPos,Vector2 endPos,int index)
    {

       var normal = endPos - startPos;//路径向量
        float angle = Vector2.SignedAngle(Vector2.right,normal);//算出向量与x轴正方向角度
        angle *= Mathf.Deg2Rad;//一定要转成弧度
        var _pList = new List<Vector3>();
        Vector3 p0, p1, p2, p3;

        //两点间距离
        float length = Vector2.Distance(startPos, endPos);


        //先把矩形沿x轴横躺
        p0 = new Vector3(startPos.x , startPos.y + lineWidth);
        p1 = new Vector3(startPos.x, startPos.y - lineWidth);
        p2 = new Vector3(startPos.x + length, startPos.y+lineWidth);
        p3 = new Vector3(startPos.x + length, startPos.y-lineWidth);
        //四个点按照0   3
        //          1   2
        //的顺序
        _pList.Add(p0);
        _pList.Add(p1);
        _pList.Add(p2);
        _pList.Add(p3);

        //然后四个点沿着startpos旋转

        for (int i = 0; i < _pList.Count; i++)
        {
            //平移
            var _p = new Vector3(_pList[i].x - startPos.x, _pList[i].y - startPos.y, 0);

            //旋转
            _p = new Vector3(Mathf.Cos(angle) * _p.x - Mathf.Sin(angle) * _p.y,
                Mathf.Sin(angle) * _p.x + Mathf.Cos(angle) * _p.y,
                0);

            //反平移
            _p += new Vector3(startPos.x, startPos.y);
            _pList[i] = _p;
        }

        


        foreach (var i in _pList)
        {
            vh.AddVert(i, lineColor, Vector2.zero);
            //加到填缝的列表里
            quadAnchorList.Add(i);
        }


        //添加三角形
        vh.AddTriangle(index * 4, index * 4 + 1, index * 4 + 2);
        vh.AddTriangle(index * 4 + 1, index * 4 + 2, index * 4 + 3);

    }

    /// 

    /// 方块与方块之间有空隙,用三角形补上
    /// 
    public void DrawTriangle(VertexHelper vh)
    {
        //0  3 | 0'  3'
        //1  2 | 1'  2'
        //这个是两个方块

        //0 | 3  0' | 3'
        //1 | 2  1' | 2'
        //在这中间再插一个方块补缝

        for (int i = 0; i < quadAnchorList.Count / 4 - 1; i++)
        {
            vh.AddVert(quadAnchorList[i * 4 + 3], lineColor, Vector2.zero);
            vh.AddVert(quadAnchorList[i * 4 + 2], lineColor, Vector2.zero);
            vh.AddVert(quadAnchorList[(i + 1) * 4 + 1], lineColor, Vector2.zero);
            vh.AddVert(quadAnchorList[(i + 1) * 4], lineColor, Vector2.zero);
        }

        for (int i=resList.Count-1;i<resList.Count*2-3;i++)
        {
            vh.AddTriangle(i * 4, i * 4 + 1, i * 4 + 2);
            vh.AddTriangle(i * 4 + 1, i * 4 + 2, i * 4 + 3);
        }
       

    }


    /// 

    /// 填充面积颜色
    /// 
    public void FillAreaColor(VertexHelper vh)
    {
        if(!fillAreaColor)
        {
            return;
        }

        for(int i=0;i<resList.Count;i++)
        {
            var p0 = resList[i];
            var p1 = resList[i];
            p1.y = 0;
            vh.AddVert(p0, ComputeColor(p0.y), Vector2.zero);
            vh.AddVert(p1, ComputeColor(p1.y), Vector2.zero);
        }
        //从补缝的下一个三角形开始
        //0   2
        //1   3
        int startIndex = (resList.Count * 2 - 3) * 4;
        for (int i=startIndex; i<startIndex+ resList.Count*2-2;i+=2)
        {

            var p0 = i;
            var p1 = i + 1;
            var p2 = i + 2;
            var p3 = i + 3;

            vh.AddTriangle(p0,p1,p3);
            vh.AddTriangle(p0, p2, p3);
        }
       
    }

    /// 

    /// 计算当前高度点的颜色
    /// 
    /// 
    /// 
    private Color ComputeColor(float pos)
    {
        float rate = pos / (heightPos - 0);

        return Color.Lerp(fillColor1, fillColor0, rate);
    }
}