【Unity】Scene 上に Image の UV と 頂点カラー を表示する

通常の画像

9Sliceのある画像

using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEngine;
using UnityEngine.UI;

namespace Yorozu.EditorTool
{
    public class EditorImageDrawer
    {
        private static List<UIVertex> _vertexList = new List<UIVertex>();
        private static Dictionary<Vector3, List<int>> _dic = new Dictionary<Vector3, List<int>>();

        private static int _cacheId;
        private static VertexHelper _cacheHelper;

        private static class Cache
        {
            public static GUIStyle Style;
            public static FieldInfo FieldInfo;

            static Cache()
            {
                Style = new GUIStyle(GUI.skin.window);

                Style.padding.bottom -= 20;
                Style.padding.left -= 7;
                Style.padding.right -= 7;
                Style.margin = new RectOffset();
                Style.richText = true;

                FieldInfo = typeof(Graphic).GetField("s_VertexHelper", BindingFlags.NonPublic | BindingFlags.Static);
            }
        }

        [DrawGizmo(GizmoType.Selected)]
        private static void DrawGizmo(Image image, GizmoType type)
        {
            if (_cacheId != image.GetInstanceID())
            {
                _cacheHelper = Cache.FieldInfo.GetValue(image) as VertexHelper;
                if (_cacheHelper == null)
                    return;

                _cacheId = image.GetInstanceID();
                image.SetVerticesDirty();
            }

            _cacheHelper.GetUIVertexStream(_vertexList);

            _dic.Clear();
            for (var index = 0; index < _vertexList.Count; index++)
            {
                var pos = image.transform.position + image.transform.rotation * _vertexList[index].position;
                if (!_dic.ContainsKey(pos))
                    _dic.Add(pos, new List<int>());

                _dic[pos].Add(index);
            }

            foreach (var pair in _dic)
            {
                var uv = _vertexList[pair.Value.First()].uv0;
                var color = ColorUtility.ToHtmlStringRGB(_vertexList[pair.Value.First()].color);
                Handles.Label(pair.Key, $"<color=#{color}>uv:{uv}</color>", Cache.Style);
            }
        }
    }
}