sprite renderer 的预览功能

unity的 sprite renderer Component 添加preview功能

参考: Unity下实现自定义模型预览窗口，支持镜头旋转

using UnityEngine;
using UnityEditor;


[CustomEditor(typeof(SpriteRenderer))]
[CanEditMultipleObjects]
public class SpriteRendererEditor : Editor
{
    private SpriteRenderer m_spriteRenderer;

    private PreviewRenderUtility m_PreviewRenderUtility;

    private void ValidateData()
    {
        if (m_PreviewRenderUtility == null)
        {
            m_PreviewRenderUtility = new PreviewRenderUtility();

            //We set the previews camera to 6 units back, look towards the middle of the 'scene'
            //m_PreviewRenderUtility.camera.transform.position = new Vector3(0, 0, 0);
            //m_PreviewRenderUtility.camera.transform.rotation = Quaternion.identity;
        }
        m_spriteRenderer = target as SpriteRenderer;
    }

    public override bool HasPr