A few assorted misfits......

[jmkimber(at)dera.gov.uk (Phil Aldis)]

Hi, some more little things....


1.	
	In this object/direct graphics thing I'm doing, I've created a
quick draw facility for all the objects by making the objects store a
backup copy of themselves in a suitably sized pixmap. Then for a
quickdraw you can device, copy=[] and while it erases anything below
it, it is very useful when you need a rough draw, e.g. when an image
is being dragged around the window. There are however two problems -
one is that it's quite difficult to minimise the pixmap so that the
plot AND ALL THE LABELLING only just fit in. At the moment I'm using
the !x.window and !y.window system variables.
	The second is how I would work out the area for a surface
plot? As DWF replied to a previous post, the !p.position and !p.clip
and !x & !y .window are all a little arbitary with surfaces. I've
noticed though that if you draw the lines on where it says the window
is, it almost looks as if it's been rotated from those positions...
   

2.	
	This one's more about general style. I'm obviously going to
have loads of different objects - plot, contour, surface etc.. - many
of which will have similar characteristics, as the direct graphics
commands have very similar keywords that can be applied. The question
is though do I have a superclass which has every graphics keyword in
and then have my main objects as subclasses - or should I simply cut
and paste ?

3.	
	When you do something like - PLOT, Findgen(100),
POSITION=[123.5, 134.76, 354.9, 400.1], /DEVICE, where does IDL
actually put the plot because the !x.window and !y.window still stay
123.5 etc... Does it Ceil or more likely does it Fix?

4.
	Even though I use it all the time, when you use
Widget_Control, TIMER=..., is the program actually executing mutiple
lines of code simultaneously. Does IDL multitask, and how much slower
do your foreground activities then go?


Cheers, 
Phil Aldis