def disp_to_pos(disp_dx, disp_dy, cog_x, cog_y):
    """
    Calculates source position in camera coordinates(x,y) from the reconstructed disp
    
    Parameters:
    -----------
    disp: DispContainer
    cog_x: float
    Coordinate x of the center of gravity of Hillas ellipse
    cog_y: float
    Coordinate y of the center of gravity of Hillas ellipse

    Returns:
    --------
    (source_pos_x, source_pos_y)
    """
    source_pos_x = cog_x + disp_dx
    source_pos_y = cog_y + disp_dy
   
    return source_pos_x, source_pos_y