OnPopulateMesh

PopulateWithErrors

TextGenerator is used to generate text for rendering, and caches vertices, character information, and line information to save memory.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    public Font font;
    void Start()
    {
        TextGenerationSettings settings = new TextGenerationSettings();
        settings.textAnchor = TextAnchor.MiddleCenter;
        settings.color = Color.red;
        settings.generationExtents = new Vector2(500.0F, 200.0F);
        settings.pivot = Vector2.zero;
        settings.richText = true;
        settings.font = font;
        settings.fontSize = 32;
        settings.fontStyle = FontStyle.Normal;
        settings.verticalOverflow = VerticalWrapMode.Overflow;
        TextGenerator generator = new TextGenerator();
        generator.Populate("I am a string", settings);
        Debug.Log("I generated: " + generator.vertexCount + " verts!");
    }
}

BaseMeshEffect

Inherited from UIBehaviour, IMeshModifier IMeshModifier: Provides ModifyMesh interface, call flow: called in Graphic

Shadow

Add an outline to the image, which is the shadow effect

 protected void ApplyShadowZeroAlloc(List<UIVertex> verts, Color32 color, int start, int end, float x, float y)
  {
      UIVertex vt;

      var neededCapacity = verts.Count + end - start;
      if (verts.Capacity < neededCapacity)
          verts.Capacity = neededCapacity;

      for (int i = start; i < end; ++i)
      {
          vt = verts[i];
          verts.Add(vt);

          Vector3 v = vt.position;
          v.x += x;
          v.y += y;
          vt.position = v;
          var newColor = color;
          if (m_UseGraphicAlpha)
              newColor.a = (byte)((newColor.a * verts[i].color.a) / 255);
          vt.color = newColor;
          verts[i] = vt;
      }
  }

  /// <summary>
  /// Duplicate vertices from start to end and turn them into shadows with the given offset.
  /// </summary>
  /// <param name="verts">Vert list to copy</param>
  /// <param name="color">Shadow color</param>
  /// <param name="start">The start index in the verts list</param>
  /// <param name="end">The end index in the vers list</param>
  /// <param name="x">The shadows x offset</param>
  /// <param name="y">The shadows y offset</param>
  protected void ApplyShadow(List<UIVertex> verts, Color32 color, int start, int end, float x, float y)
  {
      ApplyShadowZeroAlloc(verts, color, start, end, x, y);
  }

  public override void ModifyMesh(VertexHelper vh)
  {
      if (!IsActive())
          return;

      var output = ListPool<UIVertex>.Get();
      vh.GetUIVertexStream(output);

      ApplyShadow(output, effectColor, 0, output.Count, effectDistance.x, effectDistance.y);
      vh.Clear();
      vh.AddUIVertexTriangleStream(output);
      ListPool<UIVertex>.Release(output);
  }
}

my notion notes

ModifyMesh

The call used to modify the grid. Called when the shape is filling the grid.

GetUIVertexStream

Get all vertex data

ApplyShadow

Copy all the vertices, modify the x, y of the copied vertices, add the effectDistance offset, modify the color, and add the vertex data

outLine

Inherit Shadow, which is Shadow in 4 directions, copying vertices 4 times

PositionAsUV1

An IVertexModifier that sets the original vertex position in UV1 of the generated vertex.

public override void ModifyMesh(VertexHelper vh)
{
   UIVertex vert = new UIVertex();
   for (int i = 0; i < vh.currentVertCount; i++)
   {
       vh.PopulateUIVertex(ref vert, i);
       vert.uv1 =  new Vector2(vert.position.x, vert.position.y);
       vh.SetUIVertex(vert, i);
   }
}

UGUI——Text和TextEffect