Unity实现弹幕功能
发表于2018-09-26
类似B站与一些直播APP，这些软件中往往都会有一个弹幕功能，在实际的项目中肯定是用服务器客户端直接的数据来控制的，下面就来看看实现弹幕功能的方法。
效果如下
实现功能
- 支持从左到右和从右到左的方向指定
- 支持纵向的弹幕行数的动态扩展
- 支持特殊的文本外框（如用于表示弹幕为玩家自己发送的）
- 支持富文本
- 支持在屏幕没有占满的情况下，两条弹幕不重叠，并满足指定的最小间距
换行规则
弹幕信息：假设有两条弹幕D1、D2,；分别对应长度L1、L2.频幕宽度为Lp，最小间隔为Ld.
当L1<=L2时：
S1 = L1 + Lp + Ld, V1 = (L1 + Lp)/T, S2 = Lp, V2 = (L2 + Lp)/T
提前走的时间 = delta_t = S1/V1 – S2/V2 = T*[ (L1+ Lp + Ld)/(L1+Lp) – Lp/(L2+Lp) ]
当L1>L2时：
提前走的距离=ahead_s = (L1 + Ld), V1 = (L1 + Lp)/T
提前走的时间=delta_t = ahead_s/V1 = T* (L1 + Ld)/(L1 + Lp)
弹幕文本组件
using UnityEngine;
using UnityEngine.UI;
using System.Collections;
using DG.Tweening;
namespace Joker.CustomComponent.BulletScreen ｛
public enum ScrollDirection ｛
RightToLeft = 0,
LeftToRight = 1
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public class BulletTextInfo ｛
public float TextWidth;
public float SendTime;
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public class BulletScreenTextElement : MonoBehaviour ｛
[SerializeField]private BulletScreenDisplayer _displayer;
[SerializeField]private string _textContent;
[SerializeField]private bool _showBox;
[SerializeField]private ScrollDirection _scrollDirection;
[SerializeField]private Text _text;
[SerializeField]private float _textWidth;
[SerializeField]private Vector3 _startPos;
[SerializeField]private Vector3 _endPos;
public static BulletScreenTextElement Create(BulletScreenDisplayer displayer, string textContent,
bool showBox = false,
ScrollDirection direction = ScrollDirection.RightToLeft) ｛
BulletScreenTextElement instance = null;
if (displayer == null) ｛
Debug.Log("BulletScreenTextElement.Create(), displayer can not be null !");
return null;
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GameObject go = Instantiate(displayer.TextElementPrefab) as GameObject;
go.transform.SetParent(displayer.GetTempRoot());
go.transform.localPosition = Vector3.up*10000F;
go.transform.localScale = Vector3.one;
instance = go.AddComponent<BulletScreenTextElement>();
instance._displayer = displayer;
instance._textContent = textContent;
instance._showBox = showBox;
instance._scrollDirection = direction;
return instance;
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private IEnumerator Start() ｛
SetBoxView();
SetText();
//get correct text width in next frame.
yield return new WaitForSeconds(0.2f);
RecordTextWidthAfterFrame();
SetRowInfo();
SetTweenStartPosition();
SetTweenEndPosition();
StartMove();
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/// <summary>
/// The outer box view of text
/// </summary>
private void SetBoxView() ｛
Transform boxNode = transform.Find(_displayer.TextBoxNodeName);
if (boxNode == null) ｛
Debug.LogErrorFormat(
"BulletScreenTextElement.SetBoxView(), boxNode == null. boxNodeName: ｛0｝",
_displayer.TextBoxNodeName);
return;
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boxNode.gameObject.SetActive(_showBox);
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private void SetText() ｛
_text = GetComponentInChildren<Text>();
//_text.enabled = false;
if (_text == null) ｛
Debug.Log("BulletScreenTextElement.SetText(), not found Text!");
return;
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_text.alignment = _scrollDirection == ScrollDirection.RightToLeft ? TextAnchor.MiddleLeft : TextAnchor.MiddleRight;
//make sure there exist ContentSizeFitter componet for extend text width
var sizeFitter = _text.GetComponent<ContentSizeFitter>();
if (!sizeFitter) ｛
sizeFitter = _text.gameObject.AddComponent<ContentSizeFitter>();
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//text should extend in horizontal
sizeFitter.horizontalFit = ContentSizeFitter.FitMode.PreferredSize;
_text.text = _textContent;
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private void RecordTextWidthAfterFrame() ｛
_textWidth = _text.GetComponent<RectTransform>().sizeDelta.x;
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private void SetTweenStartPosition() ｛
Vector3 nor = _scrollDirection == ScrollDirection.RightToLeft ? Vector3.right : Vector3.left;
_startPos = nor * (_displayer.BulletScreenWidth / 2F + _textWidth / 2F);
transform.localPosition = _startPos;
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private void SetTweenEndPosition() ｛
Vector3 nor = _scrollDirection == ScrollDirection.RightToLeft ? Vector3.left : Vector3.right;
_endPos = nor * (_displayer.BulletScreenWidth / 2F + _textWidth / 2F);
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private void SetRowInfo() ｛
var bulletTextInfo = new BulletTextInfo() ｛
SendTime = Time.realtimeSinceStartup,
TextWidth = _textWidth
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var rowRoot = _displayer.GetRowRoot(bulletTextInfo);
transform.SetParent(rowRoot, false);
transform.localScale = Vector3.one;
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private void StartMove() ｛
//make sure the text is active.
//the default ease of DoTewwen is not Linear.
transform.DOLocalMoveX(_endPos.x, _displayer.ScrollDuration).OnComplete(OnTweenFinished).SetEase(Ease.Linear);
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private void OnTweenFinished() ｛
Destroy(gameObject, _displayer.KillBulletTextDelay);
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弹幕播放器组件
using System.Collections.Generic;
using UnityEngine;
namespace Joker.CustomComponent.BulletScreen ｛
public class BulletScreenDisplayer : MonoBehaviour ｛
public bool Enable ｛ get; set; ｝
public BulletTextInfo[] _currBulletTextInfoList;
[SerializeField]private BulletScreenDisplayerInfo _info;
public float ScrollDuration ｛
get ｛ return _info.ScrollDuration; ｝
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private float _bulletScreenWidth;
public float BulletScreenWidth ｛
get ｛ return _bulletScreenWidth; ｝
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public GameObject TextElementPrefab ｛
get ｛ return _info.TextPrefab; ｝
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public string TextBoxNodeName ｛
get ｛ return _info.TextBoxNodeName; ｝
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public float KillBulletTextDelay ｛
get ｛ return _info.KillBulletTextDelay; ｝
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public Transform ScreenRoot ｛
get ｛ return _info.ScreenRoot.transform; ｝
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public static BulletScreenDisplayer Create(BulletScreenDisplayerInfo displayerInfo) ｛
BulletScreenDisplayer instance = displayerInfo.Owner.gameObject.AddComponent<BulletScreenDisplayer>();
instance._info = displayerInfo;
return instance;
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public void AddBullet(string textContent, bool showBox = false, ScrollDirection direction = ScrollDirection.RightToLeft) ｛
BulletScreenTextElement.Create(this, textContent, showBox, direction);
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private void Start() ｛
SetScrollScreen();
InitRow();
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private void InitRow() ｛
Utility.DestroyAllChildren(_info.ScreenRoot.gameObject);
_currBulletTextInfoList = new BulletTextInfo[_info.TotalRowCount];
for (int rowIndex = 0; rowIndex < _info.TotalRowCount; rowIndex++) ｛
_currBulletTextInfoList[rowIndex] = null;
string rowNodeName = string.Format("row_｛0｝", rowIndex);
GameObject newRow = new GameObject(rowNodeName);
var rt = newRow.AddComponent<RectTransform>();
rt.SetParent(_info.ScreenRoot.transform, false);
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private void SetScrollScreen() ｛
_info.ScreenRoot.childAlignment = TextAnchor.MiddleCenter;
_info.ScreenRoot.cellSize = new Vector2(100F, _info.RowHeight);
_bulletScreenWidth = _info.ScreenRoot.GetComponent<RectTransform>().rect.width;
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public Transform GetTempRoot() ｛
return _info.ScreenRoot.transform.Find(string.Format("row_｛0｝", 0));
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public Transform GetRowRoot(BulletTextInfo newTextInfo) ｛
const int notFoundRowIndex = -1;
int searchedRowIndex = notFoundRowIndex;
newTextInfo.SendTime = Time.realtimeSinceStartup;
for (int rowIndex = 0; rowIndex < _currBulletTextInfoList.Length; rowIndex++) ｛
var textInfo = _currBulletTextInfoList[rowIndex];
//if no bullet text info exist in this row, create the new directly.
if (textInfo == null) ｛
searchedRowIndex = rowIndex;
break;
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float l1 = textInfo.TextWidth;
float l2 = newTextInfo.TextWidth;
float sentDeltaTime = newTextInfo.SendTime - textInfo.SendTime;
var aheadTime = GetAheadTime(l1, l2);
if (sentDeltaTime >= aheadTime) ｛//fit and add.
searchedRowIndex = rowIndex;
break;
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//go on searching in next row.
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if (searchedRowIndex == notFoundRowIndex) ｛//no fit but random one row.
int repairRowIndex = Random.Range(0, _currBulletTextInfoList.Length);
searchedRowIndex = repairRowIndex;
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_currBulletTextInfoList[searchedRowIndex] = newTextInfo;
Transform root = _info.ScreenRoot.transform.Find(string.Format("row_｛0｝", searchedRowIndex));
return root;
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/// <summary>
/// Logic of last bullet text go ahead.
/// </summary>
/// <param name="lastBulletTextWidth">width of last bullet text</param>
/// <param name="newCameBulletTextWidth">width of new came bullet text</param>
/// <returns></returns>
private float GetAheadTime(float lastBulletTextWidth, float newCameBulletTextWidth) ｛
float aheadTime = 0f;
if (lastBulletTextWidth <= newCameBulletTextWidth) ｛
float s1 = lastBulletTextWidth + BulletScreenWidth + _info.MinInterval;
float v1 = (lastBulletTextWidth + BulletScreenWidth) / _info.ScrollDuration;
float s2 = BulletScreenWidth;
float v2 = (newCameBulletTextWidth + BulletScreenWidth) / _info.ScrollDuration;
aheadTime = s1 / v1 - s2 / v2;
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else ｛
float aheadDistance = lastBulletTextWidth + _info.MinInterval;
float v1 = (lastBulletTextWidth + BulletScreenWidth) / _info.ScrollDuration;
aheadTime = aheadDistance / v1;
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return aheadTime;
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封装的配置脚本
using UnityEngine;
using UnityEngine.UI;
namespace Joker.CustomComponent.BulletScreen ｛
[System.Serializable]
public class BulletScreenDisplayerInfo ｛
[Header("组件挂接的节点")]
public Transform Owner;
[Header("文本预制")]
public GameObject TextPrefab;
[Header("弹幕布局组件")]
public GridLayoutGroup ScreenRoot;
[Header("初始化行数")]
public int TotalRowCount = 2;
[Header("行高（单位：像素）")]
public float RowHeight;
[Header("字体边框的节点名字")]
public string TextBoxNodeName;
[Header("从屏幕一侧到另外一侧用的时间")]
public float ScrollDuration = 8F;
[Header("两弹幕文本之间的最小间隔")]
public float MinInterval = 20F;
[Header("移动完成后的销毁延迟")]
public float KillBulletTextDelay = 0F;
public BulletScreenDisplayerInfo(Transform owner, GameObject textPrefab, GridLayoutGroup screenRoot,
int initialRowCount = 1,
float rowHeight = 100F,
string textBoxNodeName = "text_box_node_name") ｛
Owner = owner;
TextPrefab = textPrefab;
ScreenRoot = screenRoot;
TotalRowCount = initialRowCount;
RowHeight = rowHeight;
TextBoxNodeName = textBoxNodeName;
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例子：
using System.Collections;
using UnityEngine;
using System.Collections.Generic;
using Joker.CustomComponent.BulletScreen;
public class ExampleBulletScreen : MonoBehaviour ｛
public BulletScreenDisplayer Displayer;
public List<string> _textPool = new List<string>() ｛
"ウワァン!!(ノДヽ) ・・(ノ∀・)チラ 実ゎ・・嘘泣き",
"(╯#-_-)╯~~~~~~~~~~~~~~~~~╧═╧ ",
"<(￣︶￣)↗[GO!]",
"(๑•́ ₃ •̀๑) (๑¯ิε ¯ิ๑) ",
"(≖͞_≖̥)",
"(｀д′) (￣^￣) 哼！ <(｀^′)>",
"o(*￣︶￣*)o",
" ｡:.ﾟヽ(｡◕‿◕｡)ﾉﾟ.:｡+ﾟ",
"号(┳Д┳)泣",
"( ＾∀＾）／欢迎＼( ＾∀＾）",
"ドバーッ（┬┬＿┬┬）滝のような涙",
"(。┰ω┰。",
"啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊啊"
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// Use this for initialization
void Start() ｛
Displayer.Enable = true;
StartCoroutine(StartDisplayBulletScreenEffect());
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private IEnumerator StartDisplayBulletScreenEffect() ｛
while (Displayer.Enable) ｛
Displayer.AddBullet(GetText(), CheckShowBox(), GetDirection());
yield return new WaitForSeconds(0.2f);
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private string GetText() ｛
int textIndex = Random.Range(0, _textPool.Count);
var weightDict = new Dictionary<object, float>() ｛
｛"<color=yellow>｛0｝</color>", 10f｝,
｛"<color=red>｛0｝</color>", 2f｝,
｛"<color=white>｛0｝</color>", 80f｝
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string randomColor = (string)Utility.RandomObjectByWeight(weightDict);
string text = string.Format(randomColor, _textPool[textIndex]);
return text;
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private bool CheckShowBox() ｛
var weightDict = new Dictionary<object, float>() ｛
｛true, 20f｝,
｛false, 80f｝
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bool ret = (bool)Utility.RandomObjectByWeight(weightDict);
return ret;
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private ScrollDirection GetDirection() ｛
var weightDict = new Dictionary<object, float>() ｛
｛ScrollDirection.LeftToRight, 5f｝,
｛ScrollDirection.RightToLeft, 80f｝
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ScrollDirection direction = (ScrollDirection)Utility.RandomObjectByWeight(weightDict);
return direction;
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补充
关于有的同学提到的Utility.cs这个脚本，我来解释一下。这个脚本是我的工具脚本，里面包含了很多工具方法。其中我们这个案例中用到的 Utility.RandomObjectByWeight 和Utility.DestroyAllChildren（） 这两个方法都是其中的工具方法。因为这个脚本太大，所以我就只把这2个方法给提供出来，以方便大家正常的把例子工程运行起来。
using UnityEngine;
using System.Collections.Generic;
public static class Utility ｛
/// <summary>
/// 不是每次都创建一个新的map，用于减少gc
/// </summary>
private static readonly Dictionary<object, Vector2> _randomIntervalMap = new Dictionary<object, Vector2>();
/// <summary>
/// 根据权重配置随机出一种结果。
/// </summary>
/// <param name="weightInfo"></param>
/// <returns></returns>
public static object RandomObjectByWeight (Dictionary<object, float> weightInfo) ｛
object randomResult = null;
//count the total weights.
float weightSum = 0f;
foreach (var item in weightInfo) ｛
weightSum += item.Value;
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//Debug.Log( "weightSum: " + weightSum );
//value -> Vector2(min,max)
_randomIntervalMap.Clear();
//calculate the interval of each object.
float currentWeight = 0f;
foreach (var item in weightInfo) ｛
float min = currentWeight;
currentWeight += item.Value;
float max = currentWeight;
Vector2 interval = new Vector2(min, max);
_randomIntervalMap.Add(item.Key, interval);
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//random a value.
float randomValue = UnityEngine.Random.Range(0f, weightSum);
//Debug.Log( "randomValue: " + randomValue );
int currentSearchCount = 0;
foreach (var item in _randomIntervalMap) ｛
currentSearchCount++;
if (currentSearchCount == _randomIntervalMap.Count) ｛
//the last interval is [closed,closed]
if (item.Value.x <= randomValue && randomValue <= item.Value.y) ｛
return item.Key;
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else ｛
//interval is [closed, opened)
if (item.Value.x <= randomValue && randomValue < item.Value.y) ｛
randomResult = item.Key;
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return randomResult;
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/// <summary>
/// 删除所有子节点
/// </summary>
/// <param name="parent"></param>
public static void DestroyAllChildren (GameObject parent) ｛
Transform parentTrans = parent.GetComponent<Transform>();
for (int i = parentTrans.childCount - 1; i >= 0; i--) ｛
GameObject child = parentTrans.GetChild(i).gameObject;
GameObject.Destroy(child);
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来自：https://blog.csdn.net/lingyanpi/article/details/53072119