LineRenderer 簡單畫線

 通過unity內置的LineRenderer 繪製線條。

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

public class Painter : MonoBehaviour
{
    //顏色
    public Color painterColor = Color.yellow;
    //寬度
    public float Width=0.2f;

    private LineRenderer currentLineRenderer;
    private int currentPoint = -1;
    private Vector3 lastPoint;
    private bool isStart=false;



    public void EndDraw()
    {
        //鼠標擡起後，清除上一次的筆記記錄。
        currentLineRenderer = null;
        currentPoint = -1;
    }

    public bool IsLine = true;
    public void Draw()
    {
        if(IsLine)
        {
            DrawLine();
        }
        else
        {
            DrawSeal();
        }               
    }

    //劃線
    public void DrawLine()
    {
        Vector3 point = transform.position;
        //判斷現在是否有LineRenderer，配合鼠標擡起，可以再次下筆的時候新建一個畫筆
        if (!currentLineRenderer)
        {
            GameObject line = new GameObject("Line");
            currentLineRenderer = line.AddComponent<LineRenderer>();
            currentLineRenderer.numCapVertices = 90;
            //設置你喜歡的寬度
            currentLineRenderer.startWidth = currentLineRenderer.endWidth = Width;
            //給一個你喜歡的材質球
            currentLineRenderer.material = new Material(Shader.Find("Particles/Additive"));
            currentLineRenderer.startColor = painterColor;
            currentLineRenderer.endColor = painterColor;

            currentLineRenderer.material.SetColor("_TintColor", painterColor);
        
            currentLineRenderer.positionCount = 0;
            PainterContrl.Instance.AllLine.Add(currentLineRenderer);
        }
        //如果鼠標停在一個地方，就沒必要一直加點了，提升效率
        if (lastPoint != point)
        {
            //畫之前，先給LineRenderer擴容，它並不聰明
            currentLineRenderer.positionCount++;
            //把點給它，它自己會畫
            currentLineRenderer.SetPosition(++currentPoint, point);
            lastPoint = point;
        }
    }

    //畫印章
    public void DrawSeal()
    {

        Vector3 point = transform.position;
        if(IsOne)
        {
            IsOne = false;
            CreatSeal(point);
        }
        else
        {
            float Dis = Vector3.Distance(lastPoint, point);
            if(Dis > SealMidOffset)
            {
                CreatSeal(point);

            }
        }
    }
    private bool IsOne = true;
    public float SealMidOffset = 1f;

    [HideInInspector]public float SealWidth = 1;
    [HideInInspector] public float SealHeight = 1f;
    private void CreatSeal(Vector3 Point)
    {
        GameObject line = new GameObject("Line");
        currentLineRenderer = line.AddComponent<LineRenderer>();
        //給一個你喜歡的材質球
        currentLineRenderer.material = new Material(Shader.Find("Particles/Additive"));
        //設置你喜歡的寬度
        currentLineRenderer.startWidth = SealHeight;
        currentLineRenderer.endWidth = SealHeight;
        currentLineRenderer.material.SetTexture("_MainTex", PainterContrl.Instance.Seals[PainterContrl.Instance.SealIndex]);     
        currentLineRenderer.positionCount = 2;
        currentLineRenderer.SetPosition(0, Point - Vector3.up * SealWidth / 2);
        currentLineRenderer.SetPosition(1, Point + Vector3.up * SealWidth / 2);

        PainterContrl.Instance.AllLine.Add(currentLineRenderer);
        lastPoint = Point;
        currentLineRenderer = null;
    }
    //private void OnGUI()
    //{
    //    GUI.skin.label.fontSize = 50;
    //    GUI.color = Color.red;
    //    GUILayout.Label(painterColor.ToString());
    //}
}