BepInEx.ShadowAndOutline.DrawShadow(UnityEngine.Rect, UnityEngine.GUIContent, UnityEngine.GUIStyle, UnityEngine.Color, UnityEngine.Color, UnityEngine.Vector2)

public static void DrawLayoutShadow(GUIContent content, GUIStyle style, Color txtColor, Color shadowColor, Vector2 direction, params GUILayoutOption[] options) => DrawShadow(GUILayoutUtility.GetRect(content, style, options), content, style, txtColor, shadowColor, direction);

public static bool DrawButtonWithShadow(Rect r, GUIContent content, GUIStyle style, float shadowAlpha, Vector2 direction)
        {
            GUIStyle letters = new GUIStyle(style);
            letters.normal.background = null;
            letters.hover.background = null;
            letters.active.background = null;

            bool result = GUI.Button(r, content, style);

            Color color = r.Contains(Event.current.mousePosition) ? letters.hover.textColor : letters.normal.textColor;

            DrawShadow(r, content, letters, color, new Color(0f, 0f, 0f, shadowAlpha), direction);

            return result;
        }