smart-bow-infrared/Assets/BowArrow/Scripts/Components/TextSpacing.cs

// An highlighted block
using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

namespace TextSpacing
{
    public class Line
    {

        private int _startVertexIndex = 0;
        /// <summary>
        /// 起点索引
        /// </summary>
        public int StartVertexIndex
        {
            get
            {
                return _startVertexIndex;
            }
        }

        private int _endVertexIndex = 0;
        /// <summary>
        /// 终点索引
        /// </summary>
        public int EndVertexIndex
        {
            get
            {
                return _endVertexIndex;
            }
        }

        private int _vertexCount = 0;
        /// <summary>
        /// 该行占的点数目
        /// </summary>
        public int VertexCount
        {
            get
            {
                return _vertexCount;
            }
        }

        public Line(int startVertexIndex, int length)
        {
            _startVertexIndex = startVertexIndex;
            _endVertexIndex = length * 6 - 1 + startVertexIndex;
            _vertexCount = length * 6;
        }
    }


    [AddComponentMenu("UI/Effects/TextSpacing")]
    public class TextSpacing : BaseMeshEffect
    {
        public float _textSpacing = 1f;

        public override void ModifyMesh(VertexHelper vh)
        {
            if (!IsActive() || vh.currentVertCount == 0)
            {
                return;
            }

            Text text = GetComponent<Text>();
            if (text == null)
            {
                Debug.LogError("Missing Text component");
                return;
            }

            List<UIVertex> vertexs = new List<UIVertex>();
            vh.GetUIVertexStream(vertexs);
            int indexCount = vh.currentIndexCount;

            string[] lineTexts = text.text.Split('\n');

            Line[] lines = new Line[lineTexts.Length];

            //根据lines数组中各个元素的长度计算每一行中第一个点的索引，每个字、字母、空母均占6个点
            for (int i = 0; i < lines.Length; i++)
            {
                //除最后一行外，vertexs对于前面几行都有回车符占了6个点
                if (i == 0)
                {
                    lines[i] = new Line(0, lineTexts[i].Length + 1);
                }
                else if (i > 0 && i < lines.Length - 1)
                {
                    lines[i] = new Line(lines[i - 1].EndVertexIndex + 1, lineTexts[i].Length + 1);
                }
                else
                {
                    lines[i] = new Line(lines[i - 1].EndVertexIndex + 1, lineTexts[i].Length);
                }
            }

            UIVertex vt;

            for (int i = 0; i < lines.Length; i++)
            {
                Vector3 startPos = Vector3.zero;
                Vector3 endPos = Vector3.zero;
                Vector3 defaultStartPos = Vector3.zero;
                Vector3 defaultEndPos = Vector3.zero;
                for (int j = lines[i].StartVertexIndex; j <= lines[i].EndVertexIndex; j++)
                {
                    if (j < 0 || j >= vertexs.Count)
                    {
                        continue;
                    }
                    vt = vertexs[j];
                    if (defaultStartPos == Vector3.zero)
                    {
                        defaultStartPos = new Vector3(vt.position.x, vt.position.y, vt.position.z);
                    }
                    defaultEndPos = new Vector3(vt.position.x, vt.position.y, vt.position.z);
                    if (j != 0)
                    {
                        vt.position += new Vector3(_textSpacing * ((j - lines[i].StartVertexIndex) / 6), 0, 0);
                    }
                    if (startPos == Vector3.zero)
                    {
                        startPos = new Vector3(vt.position.x, vt.position.y, vt.position.z);
                    }
                    endPos = new Vector3(vt.position.x, vt.position.y, vt.position.z);
                    vertexs[j] = vt;
                    //以下注意点与索引的对应关系
                    if (j % 6 <= 2)
                    {
                        vh.SetUIVertex(vt, (j / 6) * 4 + j % 6);
                    }
                    if (j % 6 == 4)
                    {
                        vh.SetUIVertex(vt, (j / 6) * 4 + j % 6 - 1);
                    }
                }
                if (text.alignment == TextAnchor.MiddleCenter || text.alignment == TextAnchor.UpperCenter || text.alignment == TextAnchor.LowerCenter)
                {
                    Vector3 defaultCenterPos = defaultStartPos + (defaultEndPos - defaultStartPos) / 2;
                    Vector3 centerPos = startPos + (endPos - startPos) / 2;
                    for (int j = lines[i].StartVertexIndex; j <= lines[i].EndVertexIndex; j++)
                    {
                        if (j < 0 || j >= vertexs.Count)
                        {
                            continue;
                        }
                        vt = vertexs[j];
                        vt.position = vt.position + defaultCenterPos - centerPos;
                        vertexs[j] = vt;
                        //以下注意点与索引的对应关系
                        if (j % 6 <= 2)
                        {
                            vh.SetUIVertex(vt, (j / 6) * 4 + j % 6);
                        }
                        if (j % 6 == 4)
                        {
                            vh.SetUIVertex(vt, (j / 6) * 4 + j % 6 - 1);
                        }
                    }
                }
                if (text.alignment == TextAnchor.MiddleRight || text.alignment == TextAnchor.UpperRight || text.alignment == TextAnchor.LowerRight)
                {
                    Vector3 defaultRightPos = defaultEndPos;
                    Vector3 rightPos = endPos;
                    for (int j = lines[i].StartVertexIndex; j <= lines[i].EndVertexIndex; j++)
                    {
                        if (j < 0 || j >= vertexs.Count)
                        {
                            continue;
                        }
                        vt = vertexs[j];
                        vt.position = vt.position + defaultRightPos - rightPos;
                        vertexs[j] = vt;
                        //以下注意点与索引的对应关系
                        if (j % 6 <= 2)
                        {
                            vh.SetUIVertex(vt, (j / 6) * 4 + j % 6);
                        }
                        if (j % 6 == 4)
                        {
                            vh.SetUIVertex(vt, (j / 6) * 4 + j % 6 - 1);
                        }
                    }
                }
            }
        }
    }
}