public override void OnGUI()
{
GUILayout.BeginHorizontal();
GUILayout.Button("Start");
GUILayout.Button("Pause");
GUILayout.Button("Stop");
GUILayout.EndHorizontal();
var sr = GUILayout.SizeRemain;
var rect = new Vector4(GUILayout.CurrentLayout.Offset, sr.X, sr.Y);
var rectab = GUILayout.GetRectAbsolute(rect);
GUI.RectA(rectab, RigelColor.Black);
GUILayout.DrawTexture(rectab, RenderTextureIdentifier.DefaultDepthStencilView);
}