[cairo] PATCH cairo-www: Simpler explanation for how to get sharp, single-pixel-wide lines

[Lawrence D'Oliveiro]

On Wed, 17 May 2017 10:47:46 +0200, Guillermo Rodriguez wrote:

> This simpler explanation fails to explain why this "problem"
> occurs ...

It occurs because of anti-aliasing.

> ... and what is the rationale behind the current design.

You want me to include a rationale for anti-aliasing?

> It also fails to discuss alternatives such as adjusting endpoints by
> 0.5, which allows you to get sharp, single-pixel-wide lines without
> turning off antialiasing, which in many cases is undesirable.

Let me refresh your memory about the question in the FAQ:

    Question: Whenever I try drawing with a line-width of 1.0, my
    horizontal/vertical lines come out fat and blurry (eg. 2 pixels
    wide and half-intensity). What's wrong?

Note that it only discusses “horizontal/vertical” lines. This is the
specific situation where turning off antialiasing is the simplest
solution.