Unity Text字间距和行间距调整

 一、问题

在3D场景中常见文字，通过调整字体大小和锚点放大文字和清晰度，但是无法调整字间距，同时网上资料可以调整字间距，但是换行前面会出现空白。

 二、解决办法

通过重新ModifyMesh函数到达调整字间距，同时同调试发现需要给一定误差范围来解决换行前面出现空白问题。

 TextSpacing.cs

using UnityEngine;
using System.Collections;
using UnityEngine.UI;
using System;
using System.Collections.Generic;
using System.Linq;

[AddComponentMenu("UI/Effects/TextSpacing")]
public class TextSpacing : BaseMeshEffect
{

    [SerializeField]
    private float spacing_x;
    [SerializeField]
    private float spacing_y;

    private List mVertexList;

    public override void ModifyMesh(VertexHelper vh)
    {
        if (spacing_x == 0 && spacing_y == 0) { return; }
        if (!IsActive()) { return; }
        int count = vh.currentVertCount;
        if (count == 0) { return; }
        if (mVertexList == null) { mVertexList = new List(); }
        vh.GetUIVertexStream(mVertexList);
        int row = 1;
        int column = 2;
        List sub_vertexs = mVertexList.GetRange(0, 6);
        float min_row_left = sub_vertexs.Min(v => v.position.x);
        int vertex_count = mVertexList.Count;
        for (int i = 6; i < vertex_count;)
        {
            if (i % 6 == 0)
            {
                sub_vertexs = mVertexList.GetRange(i, 6);
                float tem_row_left = sub_vertexs.Min(v => v.position.x);
                Debug.LogError("min_row_left=" + min_row_left.ToString() + " tem_row_left=" + tem_row_left.ToString() + " tem_row_left <=min_row_left= " + (tem_row_left <= min_row_left).ToString());
                if (min_row_left-tem_row_left >=-10 )
                {
                    min_row_left = tem_row_left;
                    ++row;
                    column = 1;
                    //continue;
                }
            }
          
            for (int j = 0; j < 6; j++)
            {
                UIVertex vertex = mVertexList[i];
                vertex.position += Vector3.right * (column - 1) * spacing_x;
                vertex.position += Vector3.down * (row - 1) * spacing_y;
                mVertexList[i] = vertex;
                ++i;
            }
            ++column;
         
        }
        vh.Clear();
        vh.AddUIVertexTriangleStream(mVertexList);
    }
}