example.rb

class Player
  def draw
    @sprite.draw(@x, @y, 0) # Gosu::Image
    # is there any way to find out value of @x and @y after all transformations it will go through?
  end
end
class GameWindow < Gosu::Window
  def draw
    transform(@cam_x, @cam_y) do
      scale(@cam_zoom_x, @cam_zoom_y, @cam_x, @cam_y) do
        rotate(@cam_angle, @cam_x, @cam_y) do
          @player.draw
        end
      do
    end
  end
end

Not yet.