On 2/13/07, Paul Murrell <[EMAIL PROTECTED]> wrote: > Hi > > > Byron Ellis wrote: > > On 2/11/07, Geoff Russell <[EMAIL PROTECTED]> wrote: > >> Hi, > >> > >> 1. I started work on a metapost graphics driver a week or so ago and it is > >> gradually taking shape. I'm building up my own test cases into a > >> script as I go, but > >> figured you may have a "canonical testing script" of cases a driver must > >> handle? > >> > > > > I typically use demo(graphics) for initial development and then things > > like example(plotmath) to make sure I'm getting font encoding working > > properly. > > > >> 2. The clipping function looks like being a tricky problem. It seems > >> to me that the > >> callers of the driver assume that clipping affects all following calls > >> until the next > >> clipping call resets the clipping box. With metapost, the clipping > >> function clips the > >> current graphics region and has no effect on following drawing functions. > >> I'm > >> not sure how to handle this --- the 2 models are very different. > >> > > > > Sounds like you get to make a lot of clipping calls in metapost. > > > Yes, it may not be the most efficient approach, but one method would be > to keep track of the R's latest clipping region within your device > structure (just update it whenever R asks your device to set the clip > region, i.e., in MetaPost_Clip()) and enforce the current clip region > for each drawing call.
Yes, I can draw to a temp picture, then clip to the current clip region and then add the temp picture to the current picture. Easy to do, but ugly. I'll also checkout R clipping - thanks. Cheers, Geoff > > Paul > > > >> Cheers, > >> Geoff Russell > >> > >> ______________________________________________ > >> R-devel@r-project.org mailing list > >> https://stat.ethz.ch/mailman/listinfo/r-devel > >> > > > > > > -- > Dr Paul Murrell > Department of Statistics > The University of Auckland > Private Bag 92019 > Auckland > New Zealand > 64 9 3737599 x85392 > [EMAIL PROTECTED] > http://www.stat.auckland.ac.nz/~paul/ > > ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
