The Straylight Source Distribution
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


For a long while now, I've been pontificating in comp.sys.acorn.programmer
about how clever I am, and how I know how to do things properly.  Most
of the regular readers should now be thinking something along the lines
of `This [mdw] chap seems to know what he's doing, although I've never
seen any of his work.  He's been going on about these libraries and
things but we've never seen them or seen any software which uses them.
It all seems a bit fishy.'  Well, now's my time to put my money where my
mouth is.  Straylight is releasing all of its source code.  Well, the
interesting bits.

The next question ought to be `why?'  Why am I doing this?  Well, there
are two reasons, although they're both associated with Linux.  The first
reason is that I've `seen the light' of Free software, and want to do
something about my heretical past as a Software Hoarder.  I want to give
my small contribution to the world, as Freely as the GNU and Linux teams
are doing.  And I want to show off a bit, too.  The second reason is
that I'm not doing much Acorn work at all any more.  Akasha (my RiscPC)
spends most of her time turned off now, in favour of Excessus (my Linux
PC), and I don't have the time or the inclination to maintain this
rather large chunk of source code any more, so I'm giving it all to the
community which inspired it.  It feels slightly like a sort of a swan
song as I leave the Acorn world.

I'll be releasing the code in dribs and drabs over the coming weeks,
hopefully in a sensible order, so that all the software can be built
with the parts already available.  Unfortunately, most of it was never
designed to be source distributed, so there's no guarantees against
mutual dependencies.  We'll work it out as we go along, hopefully.  The
main components are:

  * Some simple header files and libraries for assembling the code, and
    some trivial utilities used in the build processes.

  * BAS -- the Basic Assembler Supplement, which allows Basic programs
    to generate AOF object code.  This is required for some of the other
    build tools.

  * SDLS -- the Straylight Dynamic Linking System.  This is already well
    known, but not well used, I think.  Maybe the sources will be
    interesting to someone.

  * Dynamite -- our dynamic-area heap manager module.  Again, well known
    software, so maybe the sources will provide some interest.

  * Sculptrix -- Straylight's 3D border rendering module.  I'm very
    proud of this code.  Provided also is the source to version 1, which
    was a horrible hack made worse by poor modifications.  Version 2
    does more, at the same speed, in less space, and more maintainably.

  * STEEL -- the Straylight Extensive Event-driven Library.  This is a
    grandiose name for a RISC_OSLib more-or-less rewrite.  There are
    Issues involved here, which I'll try to resolve -- some of the
    source files aren't `pure' Straylight code, which could cause
    problems.  I recommend against anyone using STEEL -- it's just
    needed by Glass, which is a jolly good piece of software.

  * Glass -- Straylight's template editor.  It's actually the second
    template editor I've written, although I'm thoroughly ashamed of the
    first one.  It's been around for ages, quietly circulating around a
    slowly increasing coterie of friends.  I suspect many readers
    already have copies of Glass they shouldn't have.  Well, as of this
    announcement, those copies become legal.  I'd be interested in
    hearing how far this informal distribution had reached.

  * A pile of silly utilities.  There's a mouse speed changer which
    tries to read the current speed using underhand methods (i.e.,
    peeking around OS workspace).  There's a rudimentary debugger Tim
    wrote which might be the start of something useful.

  * Sprinkle -- a little module exactly 256 bytes long which supports
    linked lists of sprite areas.

  * Constrain -- constrain the mouse pointer to a circle.  This is used
    in one of Sapphire's custom controls.

  * Sapphire -- not an acronym, but a weak pun on STEEL.  This is
    STEEL's successor.  It's a comprehensive (I think) run-time support
    system and RISC OS library for applications written in assembler.

    There are a number of bits of Sapphire which are incomplete:

      -- There's a scripting language, SAIL, which is based on the work
         Straylight did on the Termite language.  There may be
         complications on this code.

      -- There's an interface for C programs, but it's very messy.  Many
         bits of Sapphire require more expressive syntax for declaring
         data structures than C provides.

      -- There was going to be a wonderful colour selector, but it never
         really got finished.  The good bits in the current version are
         the RGB selector window (which is fully functional -- the
         RGB colour square custom control is my favourite bit) and the
         HSV colour circle, with its circular mouse constraint.

      -- The threading code needs to be rewritten, and the rest of the
         library ought to be properly multithreaded or locked.

    My favourite innovations are:

      -- The way filters work in the event manager.  We never needed to
         change the way events got dispatched, because we got it right
         the first time.

      -- Custom controls in the dialogue box system.  This one was my
         idea.

      -- The menu system.  I like the way the same menu blocks can be
         used for normal and tearoff menus.  (We designed the system
         together over a pub lunch, but Tim did all the implementation
         so lots of kudos for him.)

      -- The viewer code, and the background-redrawing gallery stuff.
         This was mine, although Tim had already done the listbox code
         on which it was based.

    There are a lot of good ideas in here (in my expert opinion) and
    some clever tricks too.  I think that anyone maintaining a RISC OS
    library should look in here.  It is, I hope, like Glass: an example
    of the benefits of the Second System Effect.

  * Sapphire example programs.  There's a small number of these, to show
    how we expected people to write Sapphire programs.  They're all
    lovingly crafted and perfectly formed.  Oh, yes.

Documentation for all of these is going to be patchy at best.  The
libraries are sort-of documented by their header files, and by the
examples provided.

That's all there'll be.

On the matter of licensing: I'll apply the GNU Library General Public
License to as much as I can, and the full General Public License to
everything else.  Software which is already OFFICIALLY available under a
different licence may continue to be licenced under those terms;
however, the existing licences only cover unmodified binaries, so if you
make modifications to the software, you're bound by all the restrictions
of the GPL.

Well, thanks for taking the time to read all of this.  It's been great
working with RISC OS, but I think I've been doing it for too long.  I'll
still hang around Acorn newsgroups and flame people whom I think are
being stupid.  I will keep porting to RISC OS in mind as I continue to
write, but as far as developing specifically for Acorn is concerned,
that's all you get.

It's 10:30 at night, I'm cold, and I've been typing this for too long.
Goodbye.  It's been great.