docs/README.DJ

		     Mesa 4.0 DOS/DJGPP Port version 0.4
		     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~



Description:
~~~~~~~~~~~~

Well, guess what... this is the DOS port of MESA 4.0, for DJGPP fans... Whoa!



Legal:
~~~~~~

MESA copyright applies.



Installation:
~~~~~~~~~~~~~

Type "make -f Makefile.DJ" to compile the libraries. Long filename support is
required during compilation. Also, you must have the DXE2 package (available
on SimTel.Net, courtesy of Andrew Zabolotny) installed in order to build the
dynamic modules; if you encounter errors, you can fetch a patched version from
my web page.
The demos are not built automagically (see Pitfalls below). To make them, use
one of the following rules:
	Static:
	    gcc -o OUT.exe IN.c -lglut -lglu -lgl
	Dynamic:
	    gcc -o OUT.exe -include dmesadxe.h IN.c -ligl -liglu -liglut -ldl
Usage of the dynamic modules requires three things:
	- include DMESADXE.H in one of the sources, so references inside
	  dynamic modules will get resolved (or use `-include' directive)
	- link against import libraries (libIgl*.a) and LIBDL.A, which will do
	  the dynamic linkage job for you
	- put the DXEs somewhere along the library path (LD_LIBRARY_PATH) or
	  in the current directory

Tested on:
	CPU:		Intel Pentium w/ MMX @166 MHz
	Mainboard:	ViA Apollo VP2 w/ 128 MB SDRAM
	Video card:	Matrox Millenium 2064W w/ 2048 kB WRAM, BIOS v3.0
	DJGPP:		djdev 2.03 + gcc v3.0.3 + make v3.79



libGL (the core):
~~~~~~~~~~~~~~~~~

Of course, MESA 4.0 core sources are required. It will probably work with
MESA 3.5, but not a chance with earlier versions due to major changes to the
MESA driver interface and the directory tree. All should compile succesfully.

The driver has its origins in ddsample.c, written by Brian Paul and found by
me in MESA 3.4.2. I touched almost all the functions, changing the coding
style :-( Sorry!

Pitfalls:
1. The current version supports only RGB[A] modes, for it made no sense to me
   to endorse color-index (aka palette) modes.
2. Single-buffered is not allowed at all. Until I can find a way to use *REAL*
   hardware acceleration, it won't get implemented.
3. Another weird "feature" is that buffer width must be multiple of 4 (I'm a
   lazy programmer and I found that the easiest way to keep buffer handling at
   peak performance ;-).



libGLU:
~~~~~~~

Mesa GLU sources are required. No comment!



libGLUT (the toolkit):
~~~~~~~~~~~~~~~~~~~~~~

Well, this "skeletal" GLUT implementation is not mine. Thanks should go to
Bernhard Tschirren, Mark Kilgard, Brian Paul and probably others (or probably
not ;-). I only changed it to be self-standing (Allegro-free). The keyboard,
mouse and timer drivers were inspired from an old project of mine (D3Xl) and
fixed with some Allegro "infusions"; I deeply thank to Shawn Hargreaves et co.

My keyboard driver used only scancodes, but since GLUT requires ASCII values
for keys, I borrowed the translation tables (and maybe more) from Allegro.
Ctrl-Alt-Del (plus Ctrl-Alt-End, for Windows users) will shut down the GLUT
engine unconditionally: it will raise SIGINT, which in turn will call the
destructors (let's hope), thus cleaning up your/my mess ;-) NB: since the
DJGPP guys ensured signal handlers won't go beyond program's space (and since
dynamic modules shall) the SIGINT can't be hooked (well, it can, but it is
useless), therefore you must live with the 'Exiting due to signal SIGINT'
message...

The mouse driver is far from complete (lack of positioning, drawing, etc),
but is enough to make almost all the demos work.

The timer is pretty versatile for it supports multiple timers with different
frequencies. It may not be the most accurate timer in the known universe, but
I think it's OK. Take this example: you have timer A with a very high rate,
and then you have timer B with very low rate compared to A; now, A ticks OK,
but timer B will probably loose precision!

As an addition, stdout and stderr are redirected and dumped upon exit. This
means that printf can be safely called during graphics, but all messages come
in bulk! A bit of a hack, I know, but I think it's better than to miss them
at all. "Borrowed" from RHIDE (Robert Hoehne) or SETEDIT (Salvador Eduardo
Tropea)... I'm not sure.

Window creating defaults: 640x480x16 at (0,0), 8-bit stencil, 16-bit accum.
However, the video mode is chosen in such a way that first window will fit.



History:
~~~~~~~~

v0.1	feb-2002	initial release
v0.2	feb-2002	+ fast triangle rasterizers
			+ enabled sw and 1.3 extensions
			+ hardware acceleration: FreeBE/AF
			+ single-buffer modes (15-, 16-, and 32-bit)
			* video mode is set by CreateVisual, not MakeCurrent
			* internal changes to support multi-buf (unfinished)
			! fixed some alpha issues... (thanks, Brian)
			+ glut has now an internal timer
			* glut changed to support multi-window (unfinished)
			! minor PC_HW corrections
v0.3	mar-2002	- removed FreeBE/AF code
			- removed single-buffer modes
v0.4	mar-2002	+ dynamic module support



Contact:
~~~~~~~~

Name:   Borca Daniel
E-mail: dborca@yahoo.com
WWW:    http://www.geocities.com/dborca/