UIGraphRenderer/Runtime/UILineRendererUtils.cs

using UnityEngine;
using UnityEngine.UI;
using XericLibrary.Runtime.MacroLibrary;

namespace XericLibrary
{
    /// <summary>
    /// UILineRenderer 的工具类，提供静态方法用于线条渲染相关的操作
    /// </summary>
    public static class UILineRendererUtils
    {
        /// <summary>
        /// 计算线路的总长度
        /// </summary>
        /// <param name="points">线路的顶点数组</param>
        /// <returns>线路的总长度</returns>
        public static float CalculateTotalLength(Vector2[] points)
        {
            if (points.Length < 2)
                return 0f;

            float totalLength = 0f;
            for (int i = 0; i < points.Length - 1; i++)
            {
                totalLength += Vector2.Distance(points[i], points[i + 1]);
            }
            return totalLength;
        }

        /// <summary>
        /// 创建线段的顶点数据
        /// 每个线段由 5 个顶点组成：
        /// - 起点的左右两个顶点
        /// - 终点的左右两个顶点
        /// - 终点的中心点（用于线段连接）
        /// </summary>
        /// <param name="point1">线段的起点</param>
        /// <param name="point2">线段的终点</param>
        /// <param name="angle0">起点到终点与终点到下一点</param>
        /// <param name="angle3">起点到终点与终点到下一点</param>
        /// <param name="thickness">线条的厚度</param>
        /// <param name="center">是否居中显示</param>
        /// <param name="rectSize">矩形变换的尺寸</param>
        /// <param name="color">线条的颜色</param>
        /// <param name="vh">用于添加顶点的 VertexHelper 对象</param>
        /// <param name="currentLength">当前线段起点在线路中的累积长度</param>
        /// <param name="totalLength">线路的总长度</param>
        public static void CreateLineSegment(Vector2 point1, Vector2 point2, float angle0, float angle3, float thickness, bool center, Vector2 rectSize, Color color, VertexHelper vh, float currentLength, float totalLength)
        {
            // 计算偏移量：如果需要居中显示，则偏移到组件中心
            Vector2 offset = center ? (rectSize / 2) : Vector2.zero;

            // 创建顶点模板，设置颜色为组件的当前颜色
            UIVertex vertex = UIVertex.simpleVert;
            vertex.color = color;

            var vector = point2 - point1;
            var vectorDistance = vector.magnitude;

            // 距离过小时不绘制
            if (vectorDistance <= float.Epsilon)
                return;
            // 线段的法线和副法线
            var vectorNormal = vector / vectorDistance;
            var vectorSubtangent = Vector2.Perpendicular(vectorNormal);
            // 计算线段长度
            float segmentLength = Vector2.Distance(point1, point2);
            // 线段单侧宽度
            var width = thickness / 2;
            //顶点偏移量
            var pointOffset1 = angle0 == 0 ? 0 : width / Mathf.Sin(angle0 / 2);
            var pointOffset2 = angle3 == 0 ? 0 : width / Mathf.Sin(angle3 / 2);
            Debug.Log($"{pointOffset1} , {pointOffset2}");
            // 计算起点和终点的UV坐标Y值
            float startUVY = totalLength > 0 ? currentLength / totalLength : 0f;
            float endUVY = totalLength > 0 ? (currentLength + segmentLength) / totalLength : 0f;
            
            // 计算起点的旋转角度，使线条垂直于线段方向
            // Quaternion point1Rotation = Quaternion.Euler(0, 0, RotatePointTowards(point1, point2) + 90);
            
            // 添加起点的左侧顶点
            // vertex.position = point1Rotation * new Vector3(-thickness / 2, 0);
            vertex.position = (Vector3)(point1 + 
                                         vectorSubtangent * -width + 
                                         vectorNormal * pointOffset1) - (Vector3)offset;
            vertex.uv0 = new Vector2(0f, startUVY); // 左侧顶点的UV
            vh.AddVert(vertex);
            
            // 添加起点的右侧顶点
            // vertex.position = point1Rotation * new Vector3(thickness / 2, 0);
            vertex.position = (Vector3)(point1 + 
                                        vectorSubtangent * width + 
                                        vectorNormal * pointOffset1) - (Vector3)offset;
            vertex.uv0 = new Vector2(1f, startUVY); // 右侧顶点的UV
            vh.AddVert(vertex);

            // 计算终点的旋转角度，使线条垂直于线段方向
            //Quaternion point2Rotation = Quaternion.Euler(0, 0, RotatePointTowards(point2, point1) - 90);
            
            // 添加终点的左侧顶点
            //vertex.position = point2Rotation * new Vector3(-thickness / 2, 0);
            vertex.position = (Vector3)(point2 + 
                                        vectorSubtangent * -width + 
                                        vectorNormal * pointOffset2) - (Vector3)offset;
            vertex.uv0 = new Vector2(0f, endUVY); // 左侧顶点的UV
            vh.AddVert(vertex);
            
            // 添加终点的右侧顶点
            //vertex.position = point2Rotation * new Vector3(thickness / 2, 0);
            vertex.position = (Vector3)(point2 + 
                                        vectorSubtangent * width + 
                                        vectorNormal * pointOffset2) - (Vector3)offset;
            vertex.uv0 = new Vector2(1f, endUVY); // 右侧顶点的UV
            vh.AddVert(vertex);

            // 添加终点的中心点，用于连接后续线段
            vertex.position = point2 - offset;
            vertex.uv0 = new Vector2(0.5f, endUVY); // 中心点的UV
            vh.AddVert(vertex);
        }

        /// <summary>
        /// 计算一个点指向另一个点的角度（以度为单位）
        /// </summary>
        /// <param name="vertex">起始点</param>
        /// <param name="target">目标点</param>
        /// <returns>旋转角度，范围为 -180 到 180 度</returns>
        public static float RotatePointTowards(Vector2 vertex, Vector2 target)
        {
            // 使用反正切函数计算两点之间的角度
            // 将弧度转换为角度返回
            return (float)(Mathf.Atan2(target.y - vertex.y, target.x - vertex.x) * (180 / Mathf.PI));
        }
    }
}