장면 뷰에서 RayCastPadding 시각화

using UnityEngine;
using UnityEngine.UI;

#if UNITY_EDITOR
using UnityEditor;
public static class RaycastPaddingDrawer
{
    [DrawGizmo(GizmoType.Selected, typeof(Image))]
    private static void DrawPadding(Image image, GizmoType gizmoType)
    {
        var pivot = image.rectTransform.pivot;
        image.rectTransform.SetPivotWithKeepingPosition(new Vector2(0.5f, 0.5f));
        image.rectTransform.ForceUpdateRectTransforms();
        var center = (Vector2)image.rectTransform.position;

        image.rectTransform.SetPivotWithKeepingPosition(new Vector2(0f, 0f));
        image.rectTransform.ForceUpdateRectTransforms();
        var leftBottom = (Vector2)image.rectTransform.position;

        image.rectTransform.SetPivotWithKeepingPosition(new Vector2(1f, 1f));
        image.rectTransform.ForceUpdateRectTransforms();
        var rightTop = (Vector2)image.rectTransform.position;

        //CanvasのRenderModeに対応
        var width = Mathf.Abs(leftBottom.x - rightTop.x);
        var ratio = image.rectTransform.rect.width / width;
        image.rectTransform.SetPivotWithKeepingPosition(pivot);
        image.rectTransform.ForceUpdateRectTransforms();

        //マイナスにすると広がるので値を反転させる
        var padding = -image.raycastPadding;

        var left = center.x - image.rectTransform.rect.width / ratio / 2f - padding.x / ratio;
        var right = center.x + image.rectTransform.rect.width / ratio / 2f + padding.z / ratio;
        var top = center.y + image.rectTransform.rect.height / ratio / 2f + padding.w / ratio;
        var bottom = center.y - image.rectTransform.rect.height / ratio / 2f - padding.y / ratio;

        Gizmos.color = Color.green;

        Gizmos.DrawLine(new Vector3(left, top), new Vector3(right, top));
        Gizmos.DrawLine(new Vector3(right, top), new Vector3(right, bottom));
        Gizmos.DrawLine(new Vector3(right, bottom), new Vector3(left, bottom));
        Gizmos.DrawLine(new Vector3(left, bottom), new Vector3(left, top));
    }

    // MIT License 
    // auther : Kohki Nakaji@nkjzm
    // Link   : https://qiita.com/nkjzm/items/297fb6921d5caca3eca9
    public static void SetPivotWithKeepingPosition(this RectTransform rectTransform, Vector2 targetPivot)
    {
        var diffPivot = targetPivot - rectTransform.pivot;
        rectTransform.pivot = targetPivot;
        var diffPos = new Vector2(rectTransform.sizeDelta.x * diffPivot.x, rectTransform.sizeDelta.y * diffPivot.y);
        rectTransform.anchoredPosition += diffPos;
    }
}
#endif