From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Emacs and Gnome Canvas Date: Sat, 17 Jul 2010 11:04:31 +0300 Message-ID: <834ofyfsa8.fsf@gnu.org> References: <4C3CD120.4040905@swipnet.se> <5A91499A-0470-43FD-9F48-560CEAD3424C@mit.edu> <83wrsyr068.fsf@gnu.org> <83iq4hhjww.fsf@gnu.org> <87sk3lbvv0.fsf@telefonica.net> <83hbk1grnq.fsf@gnu.org> <4C3EBCDC.8050709@swipnet.se> <83d3upgmwj.fsf@gnu.org> <4C3ECB4C.6050208@swipnet.se> <83aaptgly1.fsf@gnu.org> <4C3ED4F9.4080603@swipnet.se> <83630hgi0r.fsf@gnu.org> <4C3EE8D6.3020607@swipnet.se> <8339vlgcax.fsf@gnu.org> <87fwzkbzg8.fsf@telefonica.net> <877hkwag6y.fsf@stupidchicken.com> <4C400B3C.4000203@swipnet.se> <83iq4fg3eb.fsf@gnu.org> <83fwzjg17j.fsf@gnu.org> Reply-To: Eli Zaretskii NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE X-Trace: dough.gmane.org 1279353890 27220 80.91.229.12 (17 Jul 2010 08:04:50 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Sat, 17 Jul 2010 08:04:50 +0000 (UTC) Cc: jan.h.d@swipnet.se, emacs-devel@gnu.org To: YAMAMOTO Mitsuharu Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Jul 17 10:04:48 2010 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Oa2O8-0000XS-I5 for ged-emacs-devel@m.gmane.org; Sat, 17 Jul 2010 10:04:48 +0200 Original-Received: from localhost ([127.0.0.1]:38549 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Oa2O7-0001rl-9W for ged-emacs-devel@m.gmane.org; Sat, 17 Jul 2010 04:04:47 -0400 Original-Received: from [140.186.70.92] (port=51407 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Oa2Nx-0001qC-F9 for emacs-devel@gnu.org; Sat, 17 Jul 2010 04:04:38 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1Oa2Nv-0006zJ-EO for emacs-devel@gnu.org; Sat, 17 Jul 2010 04:04:37 -0400 Original-Received: from mtaout21.012.net.il ([80.179.55.169]:54504) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1Oa2Nv-0006z2-57 for emacs-devel@gnu.org; Sat, 17 Jul 2010 04:04:35 -0400 Original-Received: from conversion-daemon.a-mtaout21.012.net.il by a-mtaout21.012.net.il (HyperSendmail v2007.08) id <0L5O00E00ZKIR900@a-mtaout21.012.net.il> for emacs-devel@gnu.org; Sat, 17 Jul 2010 11:04:33 +0300 (IDT) Original-Received: from HOME-C4E4A596F7 ([77.127.61.30]) by a-mtaout21.012.net.il (HyperSendmail v2007.08) with ESMTPA id <0L5O00DYRZRJYB30@a-mtaout21.012.net.il>; Sat, 17 Jul 2010 11:04:33 +0300 (IDT) In-reply-to: X-012-Sender: halo1@inter.net.il X-detected-operating-system: by eggs.gnu.org: Solaris 10 (beta) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:127494 Archived-At: > Date: Sat, 17 Jul 2010 10:00:40 +0900 > From: YAMAMOTO Mitsuharu > Cc: jan.h.d@swipnet.se, > =09ofv@wanadoo.es, > =09cyd@stupidchicken.com, > =09emacs-devel@gnu.org >=20 > >> It also reuses functions primarily designed for drawing during > >> redisplay and that does not necessarily efficient for exposure > >> handing. >=20 > > Are you talking about draw_glyphs? If so, how is it biased in fa= vor > > of redisplay, and what would be a more efficient way of drawing > > glyphs in a specified area of the display than what draw_glyphs > > does? >=20 > As I mentioned, row overlapping is handled in rather an inefficient > way (by calling draw_glyphs for three times if the row is overlappi= ng > and overlapped). With double-buffering, we can draw whole the > background of the specified area (possibly containing multiple rows= ) > at once and then draw the whole foreground afterwards. Someone should profile the current redisplay and see which part(s) of it take most of the processing time. Without such a profile, we are making the classic mistake of optimizing in a wrong place. FWIW, Gerd M=C3=B6llman once told me that the most computationally intensive place is in face merging and realization, which is not run at all when expose events are processed. I don't know if it's true nowadays, but it's well known that guessing where the hot spots are i= s a very bad idea, because the guesses are usually plain wrong, more so if the guessing parties didn't write the code.