On May 31, 2009, at 9:08 PM, Robert O'Callahan wrote:
Here are a couple of relevant threads:
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2007-May/011284.html
http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2008-February/013906.html
Then there was a discussion on #whatwg more recently.
http://krijnhoetmer.nl/irc-logs/whatwg/20090326#l-263
So far it seems the data supports the hypothesis that authors expect
getImageData to return 1 image pixel per CSS pixel and their scripts
break when that's not true. That won't change until authors all have
high-dpi screens.
I'm not surprised. On the other hand, if we use CSS pixels, it won't
be possible for authors to get it right, even if they do have high-dpi
screens. It might be wise to have separate APIs (or a distinguishing
parameter) to indicate whether you want scaled or true resolution.
That way, unaware code gets a resolution loss, but aware code can do
the right thing. I guess you suggested something like that in the IRC
conversation you cited.
Regards,
Maciej
