Hi, On Sun, 2007-07-29 at 21:13 +0800, Dirk Reiners wrote: > Hi All, > > Allen Bierbaum wrote: > >> assuming OSG2 and IIRC the discussion, what was the reason not to use > >> the same mechanism we used for fixed point math and switch > >> Matrixr and the other r type to double. This should switch most of > >> the internal structures (transform matrices, volumes, camera parameter) > >> to double. > > > > This was our first thought too, but there were some problems that we > > came up against and I think Dirk pointed out some problems as well. > > I don't remember, honestly, it's been a while. I see it as a hack, which > is always a good reason to not do it. ;)
Hmm the r stuff actually wasn't a hack, it was meant to be the way to switch the underlying precision. Currently between float and fixed. > > The path we started down yesterday was two pronged: > > > > - We extended the Matrix class to allow interoperability between Real32 > > and Real64 types. (multiplication, transforms, comparison, assignment, > > etc). > > - We changed the MatrixStore code to track all accumulated > > transformations matrices as double Matrices. > > > > This seems to be working well so far and did not require too many > > changes in code. > > Sounds good! Did you notice any performance impact? Is that enough for > you, given that you don't have the double Transform Core? or did you add > that, too? I'm more tempted to call this the hack ;-) Because as soon as we drop the old render action the render trav action must be able to cope with fixed point math. > > If you (or anyone else) can think of a better way to do this, please let > > us know ASAP. If there is enough interest, I suggest we have a > > conference call on Monday or Tuesday to discuss the options and come to > > a consensus so we can get the code implemented in the next couple of days. > > Better no. Maybe more performant by not doing double all the time, but > if you don't see a performance issue I'm fine with it. My main question would be what would be needed to be double ?. The r mechanism switches everything which might be to broad to be useful for your problem. regards, gerrit ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Opensg-core mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensg-core
