			Mesa 4.0 DOS/DJGPP Port v1.1
			~~~~~~~~~~~~~~~~~~~~~~~~~~~~



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

Well, guess what... this is the DOS port of Mesa 4.0.4, for DJGPP fans... Whoa!
The driver has its origins in ddsample.c, written by Brian Paul and found by me
in Mesa 3.4.2.



Legal:
~~~~~~

Mesa copyright applies, provided this package is used within Mesa. For anything
else, see GPL.



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

Unzip and type:

	make -f Makefile.DJ [OPTIONS...]

Available options:

     Environment variables:
	CPU		optimize for the given processor.
			default = k6
	BIG_OPT=1	crazy optimizations; not very useful, though...
			default = no
	GLIDE		absolute path to Glide library; used with FX.
			default = $(TOP)/include/glide3
	FX=1		build for 3dfx Glide3; use it if you have the Glide
			SDK (designed for your platform), and, of course, a
			3dfx card... Note that this disables compilation of
			actual DMesa code, as Glide does all the stuff!
			default = no
	HAVE_X86=1	optimize for i386.
			default = no
	HAVE_MMX=1	MMX instructions; use only if you assembler/compiler
			supports MMX instruction set; backwards compatibility
			with older processors is still preserved.
			default = no
	HAVE_SSE=1	(see HAVE_MMX)
			default = no
	HAVE_3DNOW=1	(see HAVE_MMX)
			default = no

     Targets:
	all:		build everything
	libgl:		build GL
	libglu:		build GLU
	libglut:	build GLUT
	clean:		remove object files
	realclean:	remove all generated files



Tested on:
	CPU:		K6-2 (CXT) @500(412.5) MHz
	Mainboard:	ViA Apollo VP2/97 w/ 128 MB SDRAM
	Video card:	PowerColor Evil King3 (Voodoo3 3000) w/ 16384 kB SDRAM
	DJGPP:		djdev 2.03 + gcc v3.1 + make v3.79.1



FAQ:
~~~~

1. Compilation

   Q) I tried to run `make' and it exits because `gcc' complains it cannot find
      some stupid file.
   A) You need LFN support.
   A) When compiling for Glide (FX=1), pay attention to Glide path.

2. Dynamic modules

   Q) What are you mumbling about dynamic modules?
   A) You must have the DXE2 package (available on SimTel.Net, courtesy of
      Andrew Zabolotny) installed in order to build the dynamic modules.

   Q) I have DXE2, but I couln'd build the `dxe2gen.exe'.
   Q) I built `dxe2gen.exe', but it doesn't do the job right.
   A) There is a patched version on my web page.

   Q) DXE2 modules give me headaches...
   A) The DXE2 modules are not compulsory. The static libraries are still built
      and you can use them in the old-fashioned, classic way. For example:
	gcc -o OUT.exe IN.c -lglut -lglu -lgl

   Q) Okay, DXE2 modules are built. How can I use them?
   A) 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 (libI*.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
      For example:
	gcc -o OUT.exe -include dmesadxe.h IN.c -ligl -liglu -liglut -ldl

   Q) The application dies with "Abort!" due to unresolved symbols.
   A) This is bad! Extract the unresolved symbol list from this module. For
      example:
	dxe2gen --show-unres gl.dxe > u
      Check DMESADXE.H; the symbols in `u' must either be present here or be
      exported from another module that has to be loaded before your faulting
      one. Then recompile.

3. Using Mesa for DJGPP

   Q) Does this build work in Win9x?
   A) Yes.

   Q) Does it work under NT (W2k, XP) core?
   A) Uh... probably not!

   Q) I made a simple application and it does nothing. It exits right away. Not
      even a blank screen.
   A) The current version supports only RGB[A] modes, for it made no sense to
      me to endorse color-index (aka palette) modes.
   A) Single-buffered is not allowed at all. Until I can find a way to use
      *REAL* hardware acceleration, it won't get implemented.
   A) 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 ;-).

   Q) My demo doesn't display text. I know I used the glut font routines!
   A) Then you probably use GLUT as a DXE. Well, there is no direct access to
      variables due to the way DXE works. Read the documentation. The author of
      GLUT took this into account for _WIN32 DLL's only; I don't want to modify
      his headers. The only workaround is to link GLUT the old way :-(

   Q) The DJGPP port of Mesa is so SLOOOW! The Win32 OpenGL performs so much
      better...
   A) Is that a question? If you have a Voodoo3/Banshee card, you're lucky. The
      Glide port is on my web page. If you haven't, sorry; everything is done
      in software. Suggestions?

   Q) I have a super/mega/ultra monitor and all you can do is 60Hz? My eyes are
      leaking from the orbits...
   A) If you were compiling for Glide, see Glide info. If not, be aware that
      refresh rate control works only for VESA 3.0. The environment variable
      DMESA_REFRESH sets the default screen refresh. For example:
	set DMESA_REFRESH=75



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 many 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:
~~~~~~~~

v1.0	mar-2002	initial release
v1.1	sep-2002	+ added 3dfx Glide3 support
			+ added refresh rate control
			+ added fonts in glut
			* lots of minor changes



Contact:
~~~~~~~~

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