I'm trying to speed-up drawing proces by moving static content into Gosu::Window.initialize method and store it in Gosu::Image, to be drawn once.

I'm surprised even the following simple gradient triangle is stored improperly. When stored bitmap is drawn it has distorted top-left corner and is half-transparent.


class GameWindow < Gosu::Window
  def initialize
     …
     @triangle = record(width, height) do
      draw_triangle(width/10, height/10, Gosu::Color::RED,
                    width*9/10, height/2, Gosu::Color::GREEN,
                    width/2, height*9/10, Gosu::Color::BLUE)
    end
     …
  end

  def draw
    @triangle.draw(0, 0, 10)
     …
  end
end


Any idea why Gosu::Window.record stores the triangle garbled ?

Thanks