  ________________________________________________
 / IN PURSUIT by Martin Bazley  /  Version 3.20  /
/ //
\ \                             MAIN HELP FILE /
 
StrongED$Wrapwidth = 77
StrongED$FoldParm1 = ( "=== ",, StartOfLine )

(Non-StrongED users can ignore the above lines.  Otherwise, press
control+keypad-minus to fold the text.)

For interactive contents, do a 'List of Found' search for '==='.

=== Introduction ==

A long time ago, in a galaxy far, far away...(well, it was a long time ago
anyway!) a teacher taught me about the 'curve of pursuit'.  She thought I
could generate it on a computer, and she was half-right.  I couldn't find a
loop to work, and so the original In Pursuit was a string of LINE statements
and delay procedures.

(If you want to laugh at the abysmal nature of this set-up, you can't.
Theloop conundrum was solved a *long* time ago!)

Gradually I expanded into a myriad range of sub-programs (although the 2-
sided coloured Normal In Pursuit and the 4-sided monochrome All Possible
Lines didn't make it in until version 2.21, and the 'Graduated Diagonals'
lost out till version 3.00) and the prolific Pursuit portfolio prospered
pushily parallel to puffed-up but presently powerless programs in my
Programming pholder.  (Beat that if you can!)

As it became more difficult to pick out the In Pursuit series by name, some
bright (not to mention handsome) spark - that's me, by the way - hit upon the
idea of collecting them into one directory, and sticking a fancy picture on
the front.  Thus In Pursuit 1.00 was born.

=== WTH is 'In Pursuit'? ==

The curve of pursuit is a tad hard to describe.  Basically, you have two (or
more) lines coming at any non-reflex (<180) angle from the same point.  You
divide each line into the same number of sections (the more you have the
better the effect is, although if you have too many it can start to look
messy) and draw a line from the end of the first line to the first point of
the second line.  Then you draw a line from the second-last point of the
first line, to the second point of the second line, and so on until you've
used all the points.

I said it was hard to describe. :-> The best way to see it in action is to
answer '1' to all the questions in the index, to see the simplest design.

=== Notes ==

My programs will only draw the Pursuit curve from 2-4 lines at right angles
to each other.  So don't get your hopes up.

  =------=

The 'All Possible Lines' series is a variation on the Pursuit idea, drawing
every single line possible from every point.

The 'Graduated Diagonals' series is another variation.  It draws lines
inwards at 45.

The lines in this pursuit are drawn right up to the edge of the grid, except
on 4 sides.  In this case, they stop one short.

 =------=

The 'Solid' colour option picks a random colour from the range you
specified, and draws the graph once in that colour.

The 'Repeated Solid' one starts from the top, and draws the graph in
descending order of the available colours.  (Warning: the drawing
automatically speeds up when you use this option in 64 colours, but it will
still take a long time to finish.)

The 'By lines' one again works in descending order, but a new colour is used
for every line.

NB: the above options will not be available in monochrome mode.

  =------=

You can press Delete at any time during a program to return to the index.

When the pursuit has finished drawing, you can press Ctrl-S to take a
screenshot.  This is saved as 'Pursuit' in the application root directory.

The above location may be changed by altering <InPurs$Dir> in the !Boot and
!Run files.

=== Recent history ==

Only the most major changes in the past 4 versions are featured here.  See
the 'History' file for full info.

   Moved the *rest* of the grid-drawing code inside the REPEAT loop!
   Solid colouring will no longer pick white.
   Completely revamped all three Pursuit procedures.  There are no longer
    four seperate loops for each side - instead there is one (two for All
    Possible Lines) local loop, a new CASE...OF structure and the side-
    counter has been moved back into the main body of the program.
   Swooped through the whole program, replacing ambiguous, ugly 2/3-letter
    capital variable names with whole lower-case words.  As well as being
    clearer, this has the additional advantage of eliminating the risk that
    a variable name clashes with a keyword (I've had that problem at least
    once).
   Moved the DATA statements to the beginning of the program.  This is a
    workaround for an extremely annoying misfeature in BASIC concerning
    RESTORE commands.
   If you pick monochrome colouring, you no longer have to go through the
    'colour configuration' menu.  It wasn't as if it did anything anyway.
   Hard-wrapped both help files to a fixed width of 77 columns.
   Added folding.  The garbage at the beginning of the help files is
    interpreted by StrongED as 'set wrapwidth to 77 columns, fold everything
    beginning with three equals signs'.
   Added 'Credits' and 'Contact' sections to the main help file.
   Fully indented and spaced out the code, to increase readability.
   Combined PROCpursuit, PROCmain and the introduction into one.
   Changed much of the code structure to tackle the frequent occurrence of
    the unthinkable practice of having more than one end to loops and
    procedures.
   Rearranged most of the beginning and end of the main program to tackle
    problems including multiple mode changes, surplus OFF statements and a
    conditional END inside the loop.
   Now defines a text viewport across the right-hand side of the screen.
    This means that the 'Press SPACE or click mouse to continue' message no
    longer gets printed over the graph.
   This also means that the return message can be printed in the ordinary
    way without any of that silly fuss over line counters and DATA.
   Replaced FORs in pursuit procedures with REPEATs - longer, but cleaner to
    abort in the event of a Delete-press.
   Revamped screenshot code again.  This time it follows the loops through
    sensibly without ending prematurely.
   Actually added dates (where possible) in the history file!

=== To do ==

In rough descending order of importance:

   Pretty up the incredibly ugly status display.
   Find out how to detect cursor keys, so I can do away with the '1, 2 or
    3' system.
   Convert the help file to HTML.
   Implement much greater customizability in the now-primitive programs.

=== Credits ==

In Pursuit was brought to you by the evil 'genius' of Martin Bazley.

I was ably assisted by my loyal henchwoman (um, well, actually, she's my
sister) Harriet during the early days of this program.

The principal instrument used in the construction of this program was the
excellent text editor StrongED, which I heartily recommend.  It does all
sorts of things, such as fold the text (that's what the bit at the
beginning's for).

And, of course, thank you to Mrs. Lello for having the idea in the first
place.

=== Contact ==

Note that you may have a wait of up to two weeks before any sort of reply is
made to letters/emails.  This is not because I'm lazy (mostly) but things
just take a while to reach me.

Email: mailto:martin@bazleyfamily.co.uk

Snail mail:

Martin Bazley
Flat 8
349 North End Road
Fulham
London SW6 1NN
ENGLAND

___________________________________________________________________________
Martin Bazley
23rd August 2007

=== End