Dieter Menne wrote:
> Dear Rglers,
>
> when using a callback in rgl (Windows, if it matters)
>
> http://finzi.psych.upenn.edu/R/library/rgl/html/callbacks.html
>
> I would like to get the Asynchronous keyboard status (as least
> Shift/Control, but preferably other key) to set markers in a plot.
>
> getGraphicsEvents seems to be limited to normal graphics windows.
>
>
That's a general hardware problem, not really an rgl problem: you just
want to query the keyboard. It definitely depends on the platform.
Windows has GetKeyState, GetKeyboardState, and GetAsyncKeyState, each
with slightly different behaviour. For example,
GetKeyState(VK_SHIFT);
will tell you if either shift key is down. There are also VK_LSHIFT and
VK_RSHIFT constants to distinguish the two shift keys. Here's an inline
version (untested):
isshifted <- cfunction(signature(result="integer"),
includes = "#include <windows.h>",
body = "result[0] = getKeyState(VK_SHIFT)",
convention = ".C")
Duncan Murdoch
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