You're right. The double buffering provided by swing is too low level. The back buffer I'm using is bigger than the size of the LayerViewPanel, so that while moving around with mouse, I immediately see the pre-buffered region surrounding the current viewport, instead of seeing blank space, very much similar to panning on Google Map.
-------------------------------------------------- From: "Sunburned Surveyor" <sunburned.surve...@gmail.com> Sent: Thursday, April 09, 2009 10:51 PM To: "OpenJump develop and use" <jump-pilot-devel@lists.sourceforge.net> Subject: Re: [JPP-Devel] modelToViewTransform > Bing and others: > > I thought that Swing was already double-buffered, which would make > this modificaiton unnecessary. Are we double double-buffering? Or does > the improvement come because Swing is only double-buffering the actual > LVP envelope, while Bing is developing beyond this envelope? > > The Sunburned Surveyor > > On Thu, Apr 9, 2009 at 6:09 AM, Larry Becker <becker.la...@gmail.com> > wrote: >> Hi Bing, >> >> I haven't studied this code for a while, but it seems like the line is >> moving the origin (top for window coordinate system, bottom for world). >> >> regards, >> Larry >> >> 2009/4/9 Bing Ran <bing_...@hotmail.com> >>> >>> Hi list, >>> >>> Recently I started introducing an image back buffer in the >>> LayerViewPanel >>> in my project for the purpose creating a (another) flicker free panning >>> tool. It was the first thing I was planning to do when I started with >>> OJ. So >>> far I have made nice progress. >>> >>> Basically I have a back buffer in the LVP that is bigger than the >>> viewport >>> and the RenderingManager and all the style renderer only render to the >>> back >>> buffer and then the proper portion of the back buffer is copied to the >>> LVP >>> graphics. Additionally the back buffer is used as a cache of the >>> previous >>> rendering result and the final viewport display uses part of the back >>> buffer >>> instead of rendering afresh to reduce flickering. >>> >>> The preliminary effect of change is much appreciated by the CSRs in our >>> call center. >>> >>> >>> I'm still having issues converting geometries correctly and precisely in >>> the process though. >>> >>> >>> Now that I'm looking at the code of LVP.modelToViewTransform(...) I'm >>> wondering why this line is there: >>> >>> modelToViewTransform.translate(0, panelHeight); >>> >>> It seems to me these three lines are sufficient to convert a model point >>> to a view point. >>> >>> modelToViewTransform.scale(1, -1); >>> modelToViewTransform.scale(scale, scale); >>> modelToViewTransform.translate(-originInModel.getX(), >>> -originInModel.getY()); >>> >>> or even: >>> >>> modelToViewTransform.scale(scale, -scale); >>> modelToViewTransform.translate(-originInModel.getX(), >>> -originInModel.getY()); >>> >>> >>> Can someone share insight with this? >>> >>> >>> Thanks >>> >>> Bing >>> >>> >>> >>> >>> ------------------------------------------------------------------------------ >>> This SF.net email is sponsored by: >>> High Quality Requirements in a Collaborative Environment. >>> Download a free trial of Rational Requirements Composer Now! >>> http://p.sf.net/sfu/www-ibm-com >>> _______________________________________________ >>> Jump-pilot-devel mailing list >>> Jump-pilot-devel@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >>> >> >> >> >> -- >> http://amusingprogrammer.blogspot.com/ >> >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by: >> High Quality Requirements in a Collaborative Environment. >> Download a free trial of Rational Requirements Composer Now! >> http://p.sf.net/sfu/www-ibm-com >> _______________________________________________ >> Jump-pilot-devel mailing list >> Jump-pilot-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel >> >> > > ------------------------------------------------------------------------------ > This SF.net email is sponsored by: > High Quality Requirements in a Collaborative Environment. > Download a free trial of Rational Requirements Composer Now! > http://p.sf.net/sfu/www-ibm-com > _______________________________________________ > Jump-pilot-devel mailing list > Jump-pilot-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel > ------------------------------------------------------------------------------ This SF.net email is sponsored by: High Quality Requirements in a Collaborative Environment. Download a free trial of Rational Requirements Composer Now! http://p.sf.net/sfu/www-ibm-com _______________________________________________ Jump-pilot-devel mailing list Jump-pilot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/jump-pilot-devel
