Path: chuka.playstation.co.uk!news
From: alex@teeth.demon.co.uk (Alex Amsel)
Newsgroups: scee.yaroze.programming.2d_graphics
Subject: ANNOUNCE: new BG routine / parallax scrolling
Date: Wed, 09 Apr 1997 00:07:16 GMT
Organization: Into Beyond
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Been playing around today with a replacement for Sony's BG routines
because they don't seem very good and don't have enough functioning
options. (try it and see what I mean)

Currently I have some quite general routines that work on very similar
structures (virtually identical] to the GsBG calls so any of you with
2d code can easily change your routines over.

The current version supports multiple backgounds (as many as you
want). Each background can have its own size and structures. No size
restrictions, and /everything/ can be changed each frame. Yes, it's
incredible shrinking background time! It doesn't support GsCell.flag
which allows tiles to be flipped, but I'll probably do a version which
does support this (though it'll be slower).

I currently have ~4-5 full pal screen transparent backgrounds flying
around in 50 frames. I could do a few more for project specific stuff
or if I rewrote the routine in assembler, but this'll do for my needs.
General rgb brightness values can be set, but no on individual blocks
(easy to add if anyone wants their own version).

I'd like to put a demo out and then a library with all the calls, but
first I need someone to put together a map and some graphics! The map
is put together in the same manner as GsBG's with a few minor changes
to the GsCELL related structure. Remember I can have multiple
transparent different sized backgrounds... If anyone can help then it
will be much appreciated as I don't have time myself.

I still plan to write a version which supports rotation and 16x16,
32x32 and 64x64 tiles. This version will have 3 appropriate calls but
will be slower than the non rotation version. It should also support
scaling and  changing centers of rotation. I am considering
perspective support and perhaps some colouring support. Perspecting
probably won't get done (does anyone need it?) but I'll add colouring
support on request (again, it'll be quite a bit slower) - by this I
mean you can set rgb values for each point on the grid and goraud
shading will take place.

If completed the library will be released and can be used free by PS-X
programmers on any non-profit making product.

Anyone who is interested, let me know! And tell me what other features
you may like. If I have time I'll put them in. For anyone doing any 2d
work this lib should be invaluable. Also useful for special effects
and menus.


* Alex Amsel * Into Beyond Web Design & JAVA Programming *
* http://www.intobeyond.com  *  WWFC Play off ****ers'97 *
MM: "Hand the opposition the lead, the supporters love it"