From:	"Andrei 'old boy' Ellman" <ellman AT xs4all DOT nl>
Newsgroups:	comp.os.msdos.programmer,comp.os.msdos.djgpp,comp.graphics.algorithms,rec.games.programmer
Subject:	AllegroPak 1.0 beta 1a
Date:	Sat, 01 Nov 1997 03:41:05 +0100
Organization:	Heslington Toast Parlour, Yorkshire
Message-ID:	<345A96C1.C2B5FED9@xs4all.nl>
NNTP-Posting-Host:	asd12-16.dial.xs4all.nl
Mime-Version:	1.0
Lines:	103
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

I have just released an update to AllegroPak.

The current version (1.0 beta 1a) can be obtained from AllegroPak's homepage
at:

http://www.xs4all.nl/~ellman/ae-a/wacko/allegro/AllegroPak.html

You can also download compiled executable demos made with AllegroPak and
find out more about AllegroPak at this URL.

If you are using AllegroPak with Allegro 3.0 WIP, you will have to read the
documentation for how to change asmdef.h. AllegroPak can be used without any
modifications with Allegro 2.2.

In case you don't already know, AllegroPak is a collection of extra C
functions for use with the Allegro library. Most of them are to do with
Z-buffering, but there are also some general-purpose 3D and non-3D
functions. The main features of this package are Z-buffered versions of all
of Allegro's polygon-rendering modes (including two new ones which are
affine and perspective-correct texture-mapping that is both masked and lit)
and z-buffered sprites (both flat ones and ones with depth-maps).

I was originally hoping that this was going to be part of Allegro, but Shawn
was worried about Allegro getting too big, and wanted me to support greater
colour-depths. Since then, I have learned that it would have been better to
re-write Allegro's polygon drawers from scratch instead of hack Allegro's,
so one of these days, I may give this a complete overhaul (that is assuming
there isn't a really good freeware 3D engine for DJGPP by the time I get
round to it). I have however in the mean time decided to release what I have
done so far instead of let it lie in a forgotten corner of my Hard-Drive. I
would really appreciate feedback on this, and Shawn is still welcome to
harvest parts of this code and include it with Allegro.

My code and it's demos have the following low-level features: 

+ Z-buffering added to all of Allegro's polygon drawing modes 
+ The inclusion of polygon rendering modes: POLYTYPE_ATEX_MASK_LIT and
POLYTYPE_PTEX_MASK_LIT (z-buffered only)
+ 3D sprites (both with and without depth-maps). These sprites can be
zoomed, rotated, drawn translucent or lit (you can even z-zoom and
transparent z-blit the 3D sprite in one command).

On a slightly higher level it has: 

+ Light-sourced gouraud shaded objects (with vertex-normals) drawn with
Allegro's polygon drawer (this is done in one of the demos). 
+ Real-time (almost) light-sourced texture-mapped Z-buffered sphere
rendering.
+ Fog Shading (this is done in one of the demos). 
+ Full viewing-volume (fustrum) 3D polygon clipping (clips polygons to the
X=Z, X=-Z, Y=Z, Y=-Z and near Z=K planes).
+ Miscellaneous 3D Functions (mostly for converting between Cartesian and
Polar coordinates in 3D space). 
+ RGB <-> HSV functions that actually work, as well as RGB <-> HLS
functions. 

All features are fully documented (there is full documentation, and although
the sourcecode is heavily commented, the documentation is sufficient), and
there's even an explanation of how some of the code works in the demos. 

AllegroPak has it's own homepage at:
http://www.xs4all.nl/~ellman/ae-a/wacko/allegro/AllegroPak.html 
There, you can download AllegroPak, view the current bugslist (if you find a
bug not on the list, then please report it to me), the TODO list, see what
has been written with AllegroPak (so far, just one set of demos which is the
compiled AllegroPak examples), and find out when AllegroPak has been
updated.


Anyway, here is a summary of the changes from version 1.0 beta 1 to version
1.0 beta 1a:

+ Included instructions on how to get AllegroPak to work with Allegro 3.0
WIP (it works fine with Allegro 2.2).
+ Corrected the spelling of frustum (was spelled 'fustrum') and longitude
(was spelled 'longtitude'). If you have written any code that uses these
functions, then you will have to change the spelling in your code (this
isn't too hard if your text-editor has a search-and-replace function).
+ sphere_f() checks to see if the pointer to the rotation matrix is NULL
before it converts the rotation matrix to the format required by sphere().
This means that sphere_f() no longer crashes under DOS.
+ Documentation contains required and recommended setup.
+ The documentation now explains how masked areas are handled in flat
zprites, and how to simulate masks in zprites.
+ In SPH_DEMO, a bug is fixed that meant the light-sphere got drawn once per
other sphere instead of once per frame.
+ In SPH_DEMO, the spheres are now depth-sorted so that the frontmost gets
drawn first. This reduces the average number of times a pixel's light and
texture must be re-calculated (in Z-buffered systems, drawing the frontmost
object first is generally a good idea). The speed improvements are most
noticed when using fancy lighting and texturing modes.
+ Better feedback in 3DSPDEMO.
+ In the demos, you can now access the display of the key commands by
pressing F12.


AE.

-- 
Andrei Ellman - URL: http://www.xs4all.nl/~ellman/ae-a - ae1 AT york DOT ac DOT uk
"All I wanna do is have some fun     :-)     || ae-a AT minster DOT york DOT ac DOT uk
 I've got the feeling I'm not the only one"  || mailto:ellman AT xs4all DOT nl
     -- Sheryl Crow      :-)    ||       It's what you make of it.

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