A related question: why is a rectangle containing a single pixel defined as (x,y):(x+1,y+1) instead of (x,y):(x,y)?
Here's a discussion from some years ago that starts with some of Guido's thoughts on array indexing and moves on to the QuickDraw coordinate plane and points and rectangles, including how grid lines and points are infinitely thin/small, but pixels occupy the space between the grid lines.
Here's a discussion from some years ago that starts with some of Guido's thoughts on array indexing and moves on to the QuickDraw coordinate plane and points and rectangles, including how grid lines and points are infinitely thin/small, but pixels occupy the space between the grid lines.
https://news.ycombinator.com/item?id=6602497