Subject: bug#32932: 27.0.50; render bugs on macOS Mojave

From: Aaron Jensen <[email-masked]>
Date: Sat, 1 Feb 2020 15:05:45 -0800

On Sat, Feb 1, 2020 at 1:20 PM Alan Third <[email-masked]> wrote:
>
> Can you try the attached patch? It looks like it’s faster here, but I
> can’t really tell.

Moving the point is definitely faster. It's still slower as the window
gets larger, but that's not really new behavior (27 is that way too).
Scrolling speed is still unbearable, however.

I don't know if you've seen or read this, but I came across this just
now, but haven't looked too closely:

https://books.google.com/books?id=QyFta827Y0gC&pg=PA85&lpg=PA85&dq=quartz+double+buffering&source=bl&ots=seLTG6QxV9&sig=ACfU3U35VUiIowXtgJsaky73k5aAPSNRlw&hl=en&ppis=_c&sa=X&ved=2ahUKEwj_uOzZt7HnAhXQrJ4KHR8qDo0Q6AEwAXoECAwQAQ#v=onepage&q=quartz%20double%20buffering&f=false

I'm curious if there's some nugget in there that might lead to a way
to do normal double buffering instead of this approach, since:

"Buffering. Although you can use layers for this purpose, you
shouldn’t need to because the Quartz Compositor makes buffering on
your part unnecessary. If you must draw to a buffer, use a layer
instead of a bitmap graphics context." via
https://books.google.com/books?id=QyFta827Y0gC&pg=PA85&lpg=PA85&dq=quartz+double+buffering&source=bl&ots=seLTG6QxV9&sig=ACfU3U35VUiIowXtgJsaky73k5aAPSNRlw&hl=en&ppis=_c&sa=X&ved=2ahUKEwj_uOzZt7HnAhXQrJ4KHR8qDo0Q6AEwAXoECAwQAQ#v=onepage&q=quartz%20double%20buffering&f=false