[R-pkg-devel] Setting graphics device-copy parameters
I'm working on a graphics device in a R package, and need to set some graphical parameters for text / labels on the devices as they are initialized or reset. This feature is described in R Internals:
The three copies of the GPar structure are used to store the current parameters (accessed via gpptr), the ?device copy? (accessed via dpptr) and space for a saved copy of the ?device copy? parameters. The current parameters are, clearly, those currently in use and are copied from the ?device copy? whenever plot.new() is called (whether or not that advances to the next ?page?). The saved copy keeps the state when the device was last completely cleared (e.g. when plot.new() was called with par(new=TRUE)), and is used to replay the display list.
How do I, from a package, actually access and initialize the "device copy" ? All I've been able to find is a comment containing an older, copy-pasted comment in GraphicsDevice.h :
* 2. I found this comment in the doc for dev_Open -- looks nasty
* Any known instances of such a thing happening? Should be
* replaced by a function to query the device for preferred gpars
* settings? (to be called when the device is initialised)
*
* NOTE that it is perfectly acceptable for this
* function to set generic graphics parameters too
* (i.e., override the generic parameter settings
* which GInit sets up) all at the author's own risk
* of course :)
Thanks, Neal