Constructs a 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);