From owner-freebsd-hackers Wed Oct 2 14:49:36 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id OAA09417 for hackers-outgoing; Wed, 2 Oct 1996 14:49:36 -0700 (PDT) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.211]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id OAA09408 for ; Wed, 2 Oct 1996 14:49:29 -0700 (PDT) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id OAA04812; Wed, 2 Oct 1996 14:48:08 -0700 From: Terry Lambert Message-Id: <199610022148.OAA04812@phaeton.artisoft.com> Subject: Re: XDrawString To: rb@gid.co.uk (Bob Bishop) Date: Wed, 2 Oct 1996 14:48:08 -0700 (MST) Cc: jmacd@cs.berkeley.edu, freebsd-hackers@FreeBSD.org In-Reply-To: from "Bob Bishop" at Oct 2, 96 09:43:42 am X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk > >My results showed that XDrawString on a 2048 character string, > >where only 50 or so are on-screen takes much longer than the same > >call with only the visible length supplied. > > This is a well-known problem. When called to investigate a dog-slow X app > one of the first things I check for is drawing to points far off-screen. > > >This strikes me as a > >rather stupid way to do things, but thats just an opinion. > > You are not alone in this opinion :-) > Basically there's some nasty pathology in a clipping algorithm somewhere in > there. I personally expect the Xlib to imply a cliprect on the data it sends to the X server. I would call this an Xlib problem (unless you *know* there is backing store and want to pan locally, in which case, you are truly still updating the contents of a drawable, and it's *supposed* to work that way). Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.