From mboxrd@z Thu Jan 1 00:00:00 1970 From: erik quanstrom Date: Tue, 7 May 2013 10:10:01 -0400 To: 9fans@9fans.net Message-ID: <031b7fdd9ab256d19a5c9da921495f73@kw.quanstro.net> In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Subject: Re: [9fans] vncv sw cursor trail Topicbox-Message-UUID: 578ebaa6-ead8-11e9-9d60-3106f5b1d025 On Tue May 7 05:03:57 EDT 2013, yarikos@gmail.com wrote: > When using vncv on a terminal with software cursor (vesa, rpi) the > mouse cursor leaves a trail. This seem to be caused by the fact that > vncv loads picture updates with loadimage(2) directly to screen. > Loading to an offscreen image followed by a draw(2) to screen removes > the artifact: i'm not convinced this fix gets at the real issue. (and allocating new images might amplify latency.) the issue, and this fact this fix works must mean that devdraw(3)'s 'd' command usually doesn't cause (much) cursor flicker, but the 'y' command does. so either there is a timing or locking problem on the pi, or swcursoravoid(r) is not called for the 'y' command. i think this could be tested by putting a big fat swcursoravoid() in the 'y' case in devdraw. the pc screen.c has this warning, /* * always calling swcursorhide here doesn't cure * leaving cursor tracks nor failing to refresh menus * with the latest libmemdraw/draw.c. */ this seems to me to indicate a bug, i.e. interlocking is broken. i am using the memdraw from p9p which fixes a number of bad drawing cases. (no more blue pngs.) and i don't use vnc, so it's hard for me to replicate. - erik