implement resolution method in gui

engine/gui/Gui.cpp

@@ -173,6 +173,12 @@ Gui::~Gui()
 	m_r.destroy_shader(gui_default_vs);
 }
 
+//-----------------------------------------------------------------------------
+Vector2 Gui::resolution() const
+{
+	return m_resource->get_size();
+}
+
 //-----------------------------------------------------------------------------
 void Gui::move(const Vector3& pos)
 {

engine/gui/Gui.h

@@ -61,6 +61,7 @@ struct Gui
 						Gui(RenderWorld& render_world, GuiResource* gr, Renderer& r);
 						~Gui();
 
+	Vector2				resolution() const;
 	void				move(const Vector3& pos);
 
 	GuiRectId			create_rect(const Vector3& pos, const Vector2& size, const Color4& color);