縄で数、これ><
キープ (インカ) - Wikipedia https://ja.wikipedia.org/wiki/%E3%82%AD%E3%83%BC%E3%83%97_(%E3%82%A4%E3%83%B3%E3%82%AB)
> In OS/2 Presentation Manager, the origin of the graphics coordinate space is at the bottom left corner of the screen, with the y-coordinate increasing as you go toward the top of the screen. This is the mathematically correct coordinate system, which removes a lot of confusion when you start doing mathematics with your graphics.
へー、そうだったんだ
Why are device-independent bitmaps upside down? - The Old New Thing
https://devblogs.microsoft.com/oldnewthing/20210525-00/?p=105250
> Okay, so why are device-independent bitmaps bottom-up?
>
> For compatibility with OS/2.