Hi Dave
I should have answered this earlier, but other preoccupations put it out
of my
mind. I'm very sorry about this.
I am not sure this response is clear, or coherent, but perhaps you can find
something useful in it if you still need an answer.
You wrote:
> My installation to fails to find "rc_context" so we have a
> difference in our "setups" - which is not surprising.
> I will dig deeper.
As you may be now have worked out, this is a result of missing out a
'uses' or
'lib' command somewhere, which would have set up the appropriate search
list.
A generally useful piece of information is that poplog, when installed
with the
Birmingham packages, extends its list of indexes showing where various
things
are defined, but some of the indexes only become visible if you load the
library
file for the appropriate group of files.
If completely lost you can try, in ved
ENTER ref index
It shows some of the indexes and adds:
NOTE: Some indexes may not be available until appropriate libraries have
been loaded.
There are more tools, but I've forgotten some of them.
Anyhow, in case you have not yet solved this problem. You wrote:
> My installation to fails to find "rc_context" so we have a
> difference in our "setups" - which is not surprising.
I can't tell at which stage you failed to find it, but I think this must
be a result of missing a step in setting up one of the rclib libraries.
This is unfortunately very easy to do!
Note:
'rc' stands for relative coordinates, because the drawing commands and
related
picture interrogation commands in pop11 allow use of temporary, changing,
coordinate frames, which can also be nested.
So the very same drawing command (e.g. to draw a triangle) can produce
different
results (e.g. size and orientation of triangle) depending on which
'context' is
currently in use. Likewise commands for interrogating graphical 2d arrays
of 'pixel' values.
The library file rc_context.p is part of the core rc_graphic (relative
coordinates graphic) library which is part of the extension of the core of
poplog to support X window graphical facilities, though it was *originally*
designed to help students treat a printable 2D array of characters as a
graphical interface, around 1976, long before graphical terminals became
generally affordable, and even typing was done using paper terminals.
Pictures were typically merely arrays of asterisks.
Some of those (pseudo-)graphical facilities are provided in the core of
poplog,
and additional demos and applications are added in libraries in the packages
directory tree located at:
$usepop/pop/packages/rclib/*
rc_context is part of the core rcgraphic library, which is included in
the 'x'
(for X window) subdirectory of core poplog (i.e. not in the packages
directory):
$usepop/pop/x/
general X stuff
$usepop/pop/x/pop/
pop specific stuff
$usepop/pop/x/pop/lib
libraries, including
$usepop/pop/x/pop/lib/rc_graphic.p
This library provides a collection of graphical utilities making it easy
to do things relative to a user co-ordinate frame instead of window
It was located the X subdirectory when pop11 was several years older and
we had
facilities for accessing graphical terminals using the X window system,
not just
printable arrays.
[Before X and motif, and the Sun graphical tools arrived we had a home grown
graphical toolkit designed and implemented by Ben Rubinstein. There may be a
relic of it somewhere in the poplog tree. I've forgotten its name.]
The current rc_graphic facilities use
$usepop/pop/x/pop/lib/rc_context.p
Which should be found by 'showlib rc_context' if your poplog search
lists have
been set up properly.
rc_context allows graphical commands to be run in a context (or a
collection of
nested contexts) providing coordinate transformations.
There's some documentation in this file, which can be accessed via
the Ved command: ENTER help rclib or on the internet:
http://www.cs.bham.ac.uk/research/poplog/rclib/help/rclib
<http://www.cs.bham.ac.uk/research/poplog/rclib/help/rclib>
HOWEVER:
The core of poplog contains only the original rclib graphical package, for
drawing and accessing pictures using (possibly nested) coordinate frames.
BUT there are substantial additions to rclib in the packages directory,
and I
think some of these are used by David's popvision system:
$usepop/pop/packages/rclib/
That has a collection of subdirectories providing additional code
(including tutorial demos) and documentation, including
$usepop/pop/packages/rclib/auto/
$usepop/pop/packages/rclib/lib/
$usepop/pop/packages/rclib/teach/
$usepop/pop/packages/rclib/help/
$usepop/pop/packages/rclib/ref/
$usepop/pop/packages/rclib/demo/
Did you compile lib popvision before running any of the teach files?
E.g. in VED
ENTER lib popvision
compiles the popvision library.
You can then use ved to view a teach file:
ENTER teach vision1
you'll see near the the top of the file
1 Preliminaries
and lower down:
To use this file, you must be sitting at a colour workstation or
X-terminal, running X-windows. POPLOG version 14.2 or later must be
available.
.......
Before proceeding further, load the basic libraries that will be needed,
by marking the following indented lines and pressing <CTRL-D>. This may
take quite a while as external code (i.e. machine code compiled from C
rather than a POPLOG language) is loaded.
uses popvision ;;; search popvision libraries
uses rci_show ;;; image display utility
uses showarray ;;; array printing utility
uses arrayfile ;;; array storage utility
uses sunrasterfile ;;; alternative image storage
NOTE: if you are reading that in the Ved editor, then you can compile
all those libraries by marking the range (all file lines marked) and
then do
CTRL D
That will cause pop11 to compile and run the marked lines.
'uses' will check whether its argument library has already been compiled
and if not will compile it. (In contrast 'lib xxx' will always compile the
xxx library.)
In Ved, you can use 'showlib' to find out what's in those files, e.g.
ENTER showlib arrayfile
I don't know whether Steve has worked out the implications of all this for
his debian/ubutu -based version of poplog.
I apologise for length and/or incomprehensibility of this response!
Aaron
http://www.cs.bham.ac.uk/~axs
<http://www.cs.bham.ac.uk/~axs>
