1			Mesa 6.5 DOS/DJGPP Port v1.8
2			~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3
4
5
6Description:
7~~~~~~~~~~~~
8
9Well, guess what... this is the DOS port of Mesa 6.5, for DJGPP fans... Whoa!
10The driver uses OSMesa to draw off screen, and then blits the buffer.  This is
11not terribly efficient, and has some drawbacks, but saves maintenance costs.
12
13
14
15Legal:
16~~~~~~
17
18Mesa copyright applies.
19
20
21
22Installation:
23~~~~~~~~~~~~~
24
25Unzip and type:
26
27	make -f Makefile.DJ [OPTIONS...]
28
29Available options:
30
31     Environment variables:
32	CPU		optimize for the given processor.
33			default = pentium
34	GLIDE		path to Glide3 SDK; used with FX.
35			default = $(TOP)/glide3
36	FX=1		build for 3dfx Glide3. Note that this disables
37			compilation of most DMesa code and requires fxMesa.
38			As a consequence, you'll need the DJGPP Glide3
39			library to build any application.
40			default = no
41	X86=1		optimize for x86 (if possible, use MMX, SSE, 3DNow).
42			default = no
43
44     Targets:
45	all:		build everything
46	libgl:		build GL
47	libglu:		build GLU
48	libglut:	build GLUT
49	clean:		remove object files
50	realclean:	remove all generated files
51
52
53
54Tested on:
55	Video card:	Radeon 9500
56	DJGPP:		djdev 2.04 + gcc v4.1.0 + make v3.80
57	OS:		DOS, Win98SE, WinXP (using Videoport driver)
58
59
60
61FAQ:
62~~~~
63
641. Compilation
65
66   Q) `make' barfs and exits because it cannot find some stupid file.
67   A) You need LFN support.
68   A) When compiling for Glide (FX=1), pay attention to Glide path.
69
70   Q) Libraries built OK, but linker complains about `vsnprintf' every time I
71      compile some demo.
72   A) Upgrade to DJGPP 2.04.
73   A) Add `vsnprintf.c' to the CORE_SOURCES in `src/Makefile.DJ' (untested!).
74   A) Patch `src/mesa/main/imports.c' with the following line:
75	#define vsnprintf(buf, max, fmt, arg) vsprintf(buf, fmt, arg)
76      This hack should be safe in 90% of the cases, but if anything goes wrong,
77      don't come back to me crying.
78
79   Q) `make' complains about DXE3 or something, yet it builds the libraries.
80   A) DXE3 refers to the DJGPP dynamic modules. You'll need either the latest
81      DJGPP distro, or download the separate package from my web page. Read the
82      DXE3 documentation on how to use them.
83   A) When compiling for Glide (FX=1), make sure `glide3x.dxe' can be found in
84      LD_LIBRARY_PATH (or top `lib' directory).
85
862. Using Mesa for DJGPP
87
88   Q) Every test I tried crashes badly.
89   A) If you have compiled with SSE and you're running under plain DOS, you
90      have to disable SSE at run-time. See environment variables below.
91
92   Q) DMesa is so SLOOOW! The Win32 OpenGL performs so much better...
93   A) Is that a question? If you have a 3dfx Voodoo (any model), you're
94      lucky (check http://sourceforge.net/projects/glide for the DJGPP port).
95      If you haven't, sorry; everything is done in software.
96
97   Q) I tried to set refresh rate w/ DMesa, but without success.
98   A) Refresh rate control works only for VESA 3.0 and the 3dfx driver (in
99      which case FX_GLIDE_REFRESH will be overwritten if it is defined and
100      is not 0).
101
102   Q) I made a simple application and it does nothing. It exits right away. Not
103      even a blank screen.
104   A) Software drivers (VESA/VGA/NUL) must to be constructed as single-buffered
105      visuals.  However, DMesaSwapBuffers must be called to get any output.
106   A) Another weird "feature" is that buffer width must be multiple of 8 (I'm a
107      lazy programmer and I found that the easiest way to keep buffer handling
108      at peak performance ;-).
109
110   Q) I'm getting a "bad font!" fatal error.
111   A) Always use GLUT_STROKE_* and GLUT_BITMAP_* constants when dealing with
112      GLUT fonts. If you're using `glut.dxe', then make sure GLUT_STROKE_* and
113      GLUT_BITMAP_* are mapped to integer constants, not to the actual font
114      address (same mechanism used for Win32 _DLL).
115
116   Q) What is NUL driver good for, if I don't get any output at all?
117   A) For debugging. The NUL driver is very much like OSMesa. Everything is
118      done just the same as VESA/VGA drivers, only it doesn't touch your video
119      hardware. You can query the actual buffer by issuing:
120	DMesaGetIntegerv(DMESA_GET_BUFFER_ADDR, &buffer);
121      and dump it to a file.
122
123   Q) How do I query for a list of available video modes to choose as a visual?
124   A) This is an ugly hack, for which I'm sure I'll burn in hell.
125      First, query for a list of modes:
126	n = DMesaGetIntegerv(DMESA_GET_VIDEO_MODES, NULL);
127      If `n' is strictly positive, you allocate an array of pointers to a given
128      struct (which is guaranteed to be extended only - not changed in future):
129	struct {
130		int xres, yres;
131		int bpp;
132	} **l = malloc(n * sizeof(void *));
133      Now pass the newly allocated buffer to fill in:
134	DMesaGetIntegerv(DMESA_GET_VIDEO_MODES, (GLint *)l);
135      And collect the info:
136	for (i = 0; i < n; i++) {
137	    printf("%dx%d:%d\n", l[i]->xres, l[i]->yres, l[i]->bpp);
138	}
139
140   Q) The GLUT is incomplete.
141   A) See below.
142
143
144
145libGLUT (the toolkit):
146~~~~~~~~~~~~~~~~~~~~~~
147
148Well, this "skeletal" GLUT implementation was taken from AllegGL project and
149heavily changed. Thanks should go to Bernhard Tschirren, Mark Kilgard, Brian
150Paul and probably others (or probably not ;-). GLUT functionality will be
151extended only on an "as needed" basis.
152
153GLUT talks to hardware via PC_HW package which was put together from various
154pieces I wrote long time ago. It consists from the keyboard, mouse and timer
155drivers.
156
157My keyboard driver used only scancodes; as GLUT requires ASCII values for keys,
158I borrowed the translation tables (and maybe more) from Allegro -- many thanks
159to Shawn Hargreaves et co. Ctrl-Alt-Del (plus Ctrl-Alt-End, for Windows users)
160will shut down the GLUT engine unconditionally: it will raise SIGINT, which in
161turn will (hopefully) call the destructors, thus cleaning up your/my mess ;-)
162NB: since the DJGPP guys ensured signal handlers won't go beyond program's
163space (and since dynamic modules shall) the SIGINT can't be hooked (well, it
164can, but it is useless), therefore you must live with the 'Exiting due to
165signal SIGINT' message...
166
167The mouse driver is far from complete (lack of drawing, etc), but is enough to
168make almost all the demos work. Supports the CuteMouse WheelAPI.
169
170The timer is pretty versatile for it supports multiple timers with different
171frequencies. While not being the most accurate timer in the known universe, I
172think it's OK. Take this example: you have timer A with a very high rate, and
173then you have timer B with very low rate compared to A; now, A ticks OK, but
174timer B will probably loose precision!
175
176As an addition, stdout and stderr are redirected and dumped upon exit. This
177means that `printf' can be safely called during graphics. A bit of a hack, I
178know, because all messages come in bulk, but I think it's better than nothing.
179"Borrowed" from LIBRHUTI (Robert Hoehne).
180
181Window creating defaults: (0, 0, 300, 300), 16bpp. However, the video mode is
182chosen in such a way that first window will fit. If you need high resolution
183with small windows, set initial position far to the right (or way down); then
184you can move them back to any position right before the main loop.
185
186
187
188Environment variables:
189~~~~~~~~~~~~~~~~~~~~~~
190	DMESA_NULDRV		- (any value) force NUL driver
191	GLUT_FPS		- print frames/second statistics to stderr
192	MESA_NO_SSE		- (any value) safe option under pure DOS
193	DMESA_GLUT_REFRESH	- set vertical screen refresh rate (VESA3)
194	DMESA_GLUT_BPP		- set default bits per pixel (VGA needs 8)
195	DMESA_GLUT_ALPHA	- set default alpha bits (8)
196	DMESA_GLUT_DEPTH	- set default depth bits (16)
197	DMESA_GLUT_STENCIL	- set default stencil bits (8)
198	DMESA_GLUT_ACCUM	- set default accum bits (16)
199
200
201
202History:
203~~~~~~~~
204
205v1.0 (mar-2002)
206	initial release
207
208v1.1 (sep-2002)
209	+ added 3dfx Glide3 support
210	+ added refresh rate control
211	+ added fonts in GLUT
212	* lots of minor changes
213
214v1.2 (nov-2002)
215	* synced w/ Mesa-4.1
216	- removed dmesadxe.h
217
218v1.3 (mar-2003)
219	+ enabled OpenGL 1.4 support
220	+ added MMX clear/blit routines
221	+ enabled SGI's GLU compilation
222	+ added samples makefile
223	+ added new GLUT functions
224	+ added color-index modes
225	+ added Matrox Millennium MGA2064W driver
226	+ added 8bit FakeColor (thanks to Neil Funk)
227	+ added VGA support (to keep Ben Decker happy)
228	! fixed some compilation errors (reported by Chan Kar Heng)
229	* optimized driver for faster callback access... yeah, right :)
230	* overhauled virtual buffer and internal video drivers
231	* better fxMesa integration
232	* revamped GLUT
233	* switched to DXE3
234
235v1.4 (dec-2003)
236	+ enabled GLUT fonts with DXE
237	+ truly added multi-window support in GLUT (for Adrian Woodward)
238	* accomodated makefiles with the new sourcetree
239	* fixed some ALPHA issues
240	* minor changes to PC_HW/timer interface
241	x hacked and slashed the 3dfx driver (w/ help from Hiroshi Morii)
242
243v1.5 (jan-2004)
244	+ added interface to query available "visuals" (GLFW - Marcus Geelnard)
245	+ added GLUT timer callback
246	- removed Matrox Millennium MGA2064W driver
247	x more changes to the 3dfx driver
248
249v1.6 (aug-2004)
250	+ implemented NUL driver
251	+ added DMesaGetProcAddress and glutGetProcAddress
252	* reorganized fxMesa wrapper to handle multiple contexts
253	! fixed a horrible bug in VGA initialization routine
254	! fixed partial clears
255
256v1.7 (???-2005)
257	+ enabled OpenGL 2.0 support
258	+ added support for sw texture compression
259	+ added FreeGLUT specific functions
260	* no more GLX sources in DOS GLUT
261	* made GLUT timer callbacks less accurate but safer
262
263v1.8 (apr-2006)
264	* killed lots of code, the driver is now a front-end to OSMesa
265	* fixed problem with WinNT (http://www.volny.cz/martin.sulak/)
266	- removed 3dfx Glide3 support (temporarily?)
267
268
269
270Contact:
271~~~~~~~~
272
273Name:   Daniel Borca
274E-mail: dborca@users.sourceforge.net
275WWW:    http://www.geocities.com/dborca/
276