Unity 富文本顶点数优化

墨蓝 2022-05-19 09:39 222阅读 0赞

UGUI的Text组件勾选Rich Text复选框后支持富文本，当文本中的富文本标签非常多时，会发现三角面和顶点数会非常多，而实际显示的文字会很少，顶点数有时会多到报错。

原因：一个字符会生成6个顶点，6个顶点构成2个三角面，text会把富文本标签也进行计算，所以我们需要把Text组件下，将重复的三角面过滤掉

### 这是正常状态下text文本: ###

![70][]

### 使用大量富文本的text文本：<size=30><b><color=\#000000ff>1</color></b></size> ###

![70 1][]

### 优化后的text文本，不过有点要注意的： ###

Unity5.5版本以前还存在foreach迭代操作问题，会产生堆内存分配。不过5.5说明中说已经修复了该问题。

![70 2][]

Unity5.5以前版本：优化代码

using System.Collections.Generic;
    using System.Linq;
    using UnityEngine;
    using UnityEngine.UI;
    
    public class UIVertexOptimize : BaseMeshEffect
    {
        struct Triangle
        {
            public UIVertex v1;
            public UIVertex v2;
            public UIVertex v3;
        }
    
        class TriangleCompare : IEqualityComparer<Triangle>
        {
            public bool Equals(Triangle x, Triangle y)
            {
                return UIVertexEquals(x.v1, y.v1) && UIVertexEquals(x.v2, y.v2) && UIVertexEquals(x.v3, y.v3);
            }
    
            public int GetHashCode(Triangle obj)
            {
                return GetUIVertexHashCode(obj.v1)
                       ^ GetUIVertexHashCode(obj.v2)
                       ^ GetUIVertexHashCode(obj.v3);
            }
    
            int GetUIVertexHashCode(UIVertex vertex)
            {
                return vertex.color.a.GetHashCode()
                    ^ vertex.color.b.GetHashCode()
                    ^ vertex.color.g.GetHashCode()
                    ^ vertex.color.r.GetHashCode()
                       ^ vertex.normal.GetHashCode()
                       ^ vertex.position.GetHashCode()
                       ^ vertex.tangent.GetHashCode()
                       ^ vertex.uv0.GetHashCode()
                       ^ vertex.uv1.GetHashCode();
            }
    
            bool UIVertexEquals(UIVertex x, UIVertex y)
            {
                return x.color.a == y.color.a
                       && x.color.b == y.color.b
                       && x.color.g == y.color.g
                       && x.color.r == y.color.r
                       && x.normal == y.normal
                       && x.position == y.position
                       && x.tangent == y.tangent
                       && x.uv1 == y.uv1
                       && x.uv0 == y.uv0;
            }
        }
    
        List<UIVertex> verts = new List<UIVertex>();
        List<Triangle> tris = new List<Triangle>();
    
        public override void ModifyMesh(VertexHelper vh)
        {
            vh.GetUIVertexStream(verts);
            Debug.Log(verts.Count);
    
            OptimizeVert(ref verts);
            Debug.Log(verts.Count);
            vh.Clear();
            vh.AddUIVertexTriangleStream(verts);
        }
    
        void OptimizeVert(ref List<UIVertex> vertices)
        {
            if (tris.Capacity < vertices.Count / 3)
            {
                tris.Capacity = vertices.Count;
            }
            for (int i = 0; i <= vertices.Count - 3; i += 3)
            {
                tris.Add(new Triangle() { v1 = vertices[i], v2 = vertices[i + 1], v3 = vertices[i + 2] });
            }
            vertices.Clear();
    
            vertices.AddRange(tris.Distinct(new TriangleCompare()).SelectMany(t => new[]
            {
                t.v1,
                t.v2,
                t.v3
            }));
            tris.Clear();
        }
    }

Unity5.5及之后版本：优化Text

using System.Collections.Generic;
    using System.Linq;
    using UnityEngine;
    using UnityEngine.UI;
    
    public class UIVertexOptimize : BaseMeshEffect
    {
        struct Triangle
        {
            public UIVertex v1;
            public UIVertex v2;
            public UIVertex v3;
        }
    
        List<UIVertex> verts = new List<UIVertex>();
    
        public override void ModifyMesh(VertexHelper vh)
        {
            vh.GetUIVertexStream(verts);
            OptimizeVert(ref verts);
            vh.Clear();
            vh.AddUIVertexTriangleStream(verts);
        }
    
    
        void OptimizeVert(ref List<UIVertex> vertices)
        {
            List<Triangle> tris = new List<Triangle>();
            for (int i = 0; i < vertices.Count - 3; i += 3)
            {
                tris.Add(new Triangle() { v1 = vertices[i], v2 = vertices[i + 1], v3 = vertices[i + 2] });
            }
            vertices = tris.Distinct().SelectMany(tri =>
                new[]{
                    tri.v1,
                    tri.v2,
                    tri.v3
                }).ToList();
        }
    }

[70]: /images/20220519/11cf1173a20d4d62ac7d5497d9c5beec.png
[70 1]: /images/20220519/96002f7dfb1346f9af5f623cdbbfd18e.png
[70 2]: /images/20220519/483f25ee9203429f85a4f92a8fe0c796.png