Function CL_Gradient

	CL_Gradient::CL_Gradient();

	CL_Gradient::CL_Gradient(
		const CL_Colorf & top_left,
		const CL_Colorf & top_right,
		const CL_Colorf & bottom_left,
		const CL_Colorf & bottom_right);

	CL_Gradient::CL_Gradient(
		const CL_Colorf & first_color,
		const CL_Colorf & second_color);