unity 设计一个画虚线函数

以下是一个简单的Unity C#脚本，可用于绘制虚线：

using UnityEngine;

public class DrawDashedLine : MonoBehaviour
{
    public Material lineMaterial;
    public float lineWidth = 1.0f;
    public float dashLength = 0.1f;
    public float gapLength = 0.1f;

    private Vector3 startPoint;
    private Vector3 endPoint;

    void OnPostRender()
    {
        if (!lineMaterial)
        {
            Debug.LogError("Please assign a material on the inspector");
            return;
        }

        GL.PushMatrix();
        lineMaterial.SetPass(0);
        GL.LoadOrtho();

        GL.Begin(GL.LINES);
        GL.Color(lineMaterial.color);

        Vector3 direction = (endPoint - startPoint).normalized;
        float distance = Vector3.Distance(startPoint, endPoint);

        Vector3 currentPos = startPoint;
        float currentLength = 0;

        while (currentLength < distance)
        {
            GL.Vertex(currentPos);

            currentLength += dashLength;
            currentPos += direction * dashLength;

            if (currentLength < distance)
            {
                GL.Vertex(currentPos);

                currentLength += gapLength;
                currentPos += direction * gapLength;
            }
        }

        GL.End();
        GL.PopMatrix();
    }

    public void SetPoints(Vector3 start, Vector3 end)
    {
        startPoint = start;
        endPoint = end;
    }
}

使用方法：

1. 将此脚本附加到一个空对象上。
2. 将要绘制虚线的两个点传递给 `SetPoints` 函数。
3. 将要使用的材质分配给 `lineMaterial` 变量。
4. 可选：更改线宽、虚线长度和间隙长度。

示例代码：

using UnityEngine;

public class Example : MonoBehaviour
{
    public DrawDashedLine dashedLine;

    void Update()
    {
        if (Input.GetMouseButtonDown(0))
        {
            Vector3 start = Camera.main.ScreenToWorldPoint(Input.mousePosition);
            Vector3 end = start + new Vector3(2, 0, 0);

            dashedLine.SetPoints(start, end);
        }
    }
}

此示例将在鼠标单击时绘制一条从鼠标位置开始的虚线。