From: YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
To: "Jan Djärv" <jan.h.d@swipnet.se>
Cc: Lars Magne Ingebrigtsen <larsi@gnus.org>,
Eli Zaretskii <eliz@gnu.org>,
emacs-devel@gnu.org
Subject: Re: image-size
Date: Fri, 21 Jun 2013 09:46:04 +0900 [thread overview]
Message-ID: <wl7ghouw8j.wl%mituharu@math.s.chiba-u.ac.jp> (raw)
In-Reply-To: <2D9A8A78-829E-4AEC-BA3E-9409A1457053@swipnet.se>
>>>>> On Thu, 20 Jun 2013 23:42:28 +0200, Jan Djärv <jan.h.d@swipnet.se> said:
>> Of course there is no X stuff on Windows. But if you're running
>> over X, lookup_image pushes data over X, for some reason or other.
>> I have no idea what the reason might be, but perhaps somebody else
>> does.
> lookup_image calls img->type->load, and jpeg_load creates an X
> pixmap (x_create_x_image_and_pixmap), i.e. on the X server, and
> copies the image into the pixmap, i.e. transfers it to the server
> (XPutImage).
> The functions are totally different for X, W32 and NS, so how it
> works on W32 is totally irrelevant for X and vice versa.
> Loading the image just to determine the size is a huge overhead.
> The image loading routines already know the image size before
> sending it to the server (or the equivalent for W32 and NS),
> otherwise they could not allocate the right size for the Pixmap. No
> Imagemagic is needed to figure out the image size.
Right. And as I mentioned in (*), a possible way to solve this
problem is to defer the creation of Pixmap (server side resource) from
XImage (client side resource) until the actual display happens (i.e.,
at prepare_image_for_display rather than lookup_image), so as to avoid
unnecessary round trip of image data between the X11 server and
client.
*: http://lists.gnu.org/archive/html/emacs-devel/2010-09/msg01285.html
On the Carbon port and its descendants, deferring the creation of
image data for display (CGImage on OS X) from the raw pixel data
(struct _XImage, a custom data structure made after X11) as above has
been done for a long time. And I've never heard of a problem about
that.
YAMAMOTO Mitsuharu
mituharu@math.s.chiba-u.ac.jp
next prev parent reply other threads:[~2013-06-21 0:46 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-20 10:04 image-size Lars Magne Ingebrigtsen
2013-06-20 12:18 ` image-size Lars Magne Ingebrigtsen
2013-06-20 16:52 ` image-size Eli Zaretskii
2013-06-20 16:01 ` image-size Eli Zaretskii
2013-06-20 16:50 ` image-size Lars Magne Ingebrigtsen
2013-06-20 16:55 ` image-size Lars Magne Ingebrigtsen
2013-06-20 17:16 ` image-size Eli Zaretskii
2013-06-20 17:54 ` image-size Lars Magne Ingebrigtsen
2013-06-20 18:15 ` image-size Eli Zaretskii
2013-06-20 18:31 ` image-size Eli Zaretskii
2013-06-20 18:46 ` image-size Lars Magne Ingebrigtsen
2013-06-20 19:11 ` image-size Eli Zaretskii
2013-06-20 19:18 ` image-size Lars Magne Ingebrigtsen
2013-06-20 19:37 ` image-size Eli Zaretskii
2013-06-20 19:52 ` image-size David Engster
2013-06-20 20:50 ` image-size Eli Zaretskii
2013-06-20 19:34 ` image-size Lars Magne Ingebrigtsen
2013-06-20 19:42 ` image-size Eli Zaretskii
2013-06-20 19:52 ` image-size Lars Magne Ingebrigtsen
2013-06-20 20:53 ` image-size Eli Zaretskii
2013-06-20 20:57 ` image-size Lars Magne Ingebrigtsen
2013-06-20 21:06 ` image-size Lars Magne Ingebrigtsen
2013-06-21 6:12 ` image-size Eli Zaretskii
2013-06-20 21:42 ` image-size Jan Djärv
2013-06-21 0:46 ` YAMAMOTO Mitsuharu [this message]
2013-06-21 6:27 ` image-size Lars Magne Ingebrigtsen
2013-06-26 8:25 ` image-size YAMAMOTO Mitsuharu
2013-06-26 10:39 ` image-size YAMAMOTO Mitsuharu
2013-06-26 12:04 ` image-size Lars Magne Ingebrigtsen
2013-06-27 0:46 ` image-size Lars Magne Ingebrigtsen
2013-06-27 2:49 ` image-size Stefan Monnier
2013-06-28 2:46 ` image-size YAMAMOTO Mitsuharu
2013-06-28 3:12 ` image-size Juanma Barranquero
2013-06-28 3:45 ` image-size YAMAMOTO Mitsuharu
2013-06-21 6:15 ` image-size Eli Zaretskii
2013-06-21 7:34 ` image-size Jan Djärv
2013-06-21 8:27 ` image-size Eli Zaretskii
2013-06-21 9:03 ` image-size Jan Djärv
2013-06-21 9:07 ` image-size Lars Magne Ingebrigtsen
2013-06-21 9:58 ` image-size Eli Zaretskii
2013-06-21 9:57 ` image-size Eli Zaretskii
2013-06-21 6:13 ` image-size Eli Zaretskii
2013-06-21 15:54 ` image-size Willem Rein Oudshoorn
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