DrawingScope

struct in UnityEditor

描述

用于自动设置和恢复 Handles.color 和/或 Handles.matrix 的可处置 Helper 结构。

此结构允许您暂时设置代码块内的 Handles.color 和/或 Handles.matrix 的值，并在退出作用域时自动将它们恢复为之前的值。

using UnityEditor;
using UnityEngine;

// a custom editor that draws a labeled circle around the selected MeshRenderer in the scene view
[CustomEditor(typeof(MeshRenderer))]
public class MeshRendererEditor : Editor
{
    protected virtual void OnSceneGUI()
    {
        MeshRenderer meshRenderer = (MeshRenderer)target;

        // get an orientation pointing from the selected object to the camera
        Vector3 cameraToTarget = Camera.current.transform.position - meshRenderer.transform.position;
        Quaternion billboardOrientation = Quaternion.LookRotation(cameraToTarget, Camera.current.transform.up);

        // set the handle matrix to the target's position, oriented facing the camera
        Matrix4x4 matrix = Matrix4x4.TRS(meshRenderer.transform.position, billboardOrientation, Vector3.one);
        using (new Handles.DrawingScope(Color.magenta, matrix))
        {
            // draw a magenta circle around the selected object with a label at the top
            Vector3 size = meshRenderer.bounds.size;
            float radius = Mathf.Max(size.x, size.y, size.z);
            Handles.DrawWireArc(Vector3.zero, Vector3.forward, Vector3.right, 360f, radius);
            Handles.Label(Vector3.up * radius, meshRenderer.name);
        }
    }
}