[分享]OpenGL的一些资源

FAQ for glut

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Q1: I've tried to use the "mkmkfiles.imake" script to generate
Makefiles so I can build GLUT, but it doesn't seem to work. What
should I try?

A1: While Imakefiles are supposted to be system independent (hence
the "I"), the commands to translate Imakefiles into Makefiles
varies from system to system. The X Consortium provides a command
called "xmkmf", but vendors do not put this command in a
consistent place. The "mkmkfiles.imake" script tries its best to
generate Makefiles, but may get confused by different vendors
configurations that I am not aware of.

It is also possible the imake configuration files (typically
located at /usr/lib/X11/config) are buggy or from a very old
version of X.

SGI users can benefit from using the "mkmkfile.sgi" script that
uses SGI's parallel make, though "mkmkfiles.imake" should work
too.

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Q2: GLUT needs improved menus, dialog boxes, scrollbars, text
entry fields, etc. to be useful to me. What should I do?

A2: GLUT does not pretend to be a full-featured graphical user
interface toolkit.

You _could_ write these sorts of GUI objects using GLUT and OpenGL
if you needed to. The other alternative is to use Motif or
whatever full featured toolkit you have.

A little toolkit called micro-UI uses OpenGL for rendering and is
based on GLUT. The toolkit was developed by Tom Davis. See the
README.mui file the accompanies GLUT 3.5 and up.

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Q3: What new things are in GLUT 3.0?

A3: See README.glut3 or read The OpenGL Utility (GLUT) Programming
Interface document.

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Q4: Is there a version of GLUT for Windows NT or Windows 95?

A4: As of GLUT 3.5, GLUT now builds for both Win32 and X11 window
systems. Much thanks to Nate Robins. See the README.win file
contained in GLUT 3.5 for details. GLUT 3.6 improved the Win32
GLUT support considerably.

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Q5: Is there a version of GLUT for OS/2?

A5: Yes. I believe a version based on GLUT 2.x is distributed on an
OS/2 OpenGL developer's CD-ROM.

You may have reasonable luck porting the Win32 version of the
GLUT 3.6 distribution to OS/2. If you manage to do this, please
contact me.

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Q6: Is there a version of GLUT for the Power Macintosh?

A6: Conix Graphics supplies GLUT 3.5 with their Macintosh OpenGL
implementation. See http://www.conix3d.com.

Was told by Template Graphics that an incomplete version of
GLUT had been developed for their OpenGL product for the Power
Macintosh. I am not sure if it was ever completed or made
available.

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Q7: I'm hesitant about upgrading to GLUT 3.0 since I've got things
working will with GLUT 2.3. Is the transition painful?

A7: I do not believe so. There are two changes worth noting that
_may_ affect programs you have written.

First, you need a display callback registered before your display
your windows on the screen. It did not make sense for this to not
be true. In all likeihood, this should not affect your GLUT
programs if they written well.

Second, you can no longer change, create, or destroy menus while
pop-up menus are in use. Before, you could do this, but it meant
a menu might be changed while in use. It was near impossible to
describe what should happen in the case of menus being changed
while in use that was likely to be portable to the way other
window systems handled menus, so I made the practice illegal.

You can register a menu status callback to know when menus become
used and unused to avoid changing menus while they are in use.

For more details about what has changed, see the CHANGES file.

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Q8: So how do I use GLUT and Motif together?

A8: You don't. To make GLUT simple and easy-to-program, GLUT
supplies its own event processing loop. This makes it nearly
impossible to combine GLUT and Motif. If you want Motif, you
probably want a full-featured toolkit, and you ship skip GLUT and
implement your application directly in Motif.

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Q9: I have a bunch of simple OpenGL programs using the aux toolkit
descibed in the OpenGL Programming Guide (the "red" book). Is
there an easy way to convert them to GLUT?

A9: In the progs/redbook directory, there is a script named
aux2glut.sed It will give you a good start at converting simple
aux calls to their GLUT equivalents. It is a good start, but
you'll still have to hand edit some things.

Here's a usage example:

sed -f aux2glut.sed < aux_prog. > glut_prog.c

Note that the second edition of the OpenGL Programming Guide uses
GLUT and not the aux toolkit.

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Q10: I have IRIX 6.2 (or 6.1) and I'd like to write GLUT programs
run in true 64-bit and/or benefit from the recent, faster MIPS
processors. How do I build GLUT to support these newer
application binary interfaces (ABIs)?

A10: See README.irix6

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Q11: I'd like to write FORTRAN programs using GLUT and OpenGL. How
do I use GLUT with FORTRAN?

A11: GLUT does have a FORTRAN language binding.

For instructions for building a binding library for Silicon
Graphics workstations, see README.fortran

If you want to use GLUT and OpenGL or Mesa on with Fortran on
non-SGI systems, I recommend that you check, William Mitchell's
f90gl home page: http://math.nist.gov/f90gl/

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Q12: I'd like to use the sophisticated input devices that GLUT
supports. What should I know about this?

A12: GLUT uses the X Input extension to talk to these devices. Because
the X Input extension gives a framework for supporting input
devices, but does not manadate how particular devices are
supported, it is possible that each vendor supports the same input
devices differently.

GLUT as implemented supports SGI's means of advertising the
tablet, dial & button box, and Spaceball devices. I am not sure
how other vendors support these devices. For the details of SGI's
support for these devices, see README.xinput Since there is no
benefit in each vendor supporting these same devices in a
different an incompatible way, I encourage other vendors to
implement their devices in this same manner.

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Q13: Can I use GLUT and Open Inventor?

A13: Yes. See the README.inventor file. Also, some source code
examples can be found at progs/inventor

Because the Open Inventor development enviornment is not supported
on all systems, the Inventor example programs are not built by
default, and the Makefile there only support SGI systems.

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Q14: I have Sun workstation, and it is supposed to support overlays.
So why does GLUT not use them?

A14: GLUT uses the SERVER_OVERLAY_VISUALS convention that advertises
overlay visuals. Most major workstation vendors support this
convention (DEC, HP, IBM, SGI), but Sun only support the
SERVER_OVERLAY_VISUALS in their latest Creator 3D hardware.

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Q15: The stroke font used for GLUT looks familar. Where did it come
from?

A15: The data for the "stroke roman" font is lifted from the X11R5
PEX sample implementation.

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Q31: What is new in GLUT 3.4?

A31: GLUT 3.4 is an incremental release. An Ada binding for SGI
machines is included along with an Ada example. Many new sample
programs. Several such as dinoshade.c demonstrate real-time
rendering techniques relevant for games. Examples using Sam
Leffler's libtiff library for loading, drawing and writing TIFF
image files. GLUT version of the facial animation "geoview"
decibed in the Parke and Water's book "Computer Facial
Animation". New API interfaces to be made part of the GLUT 4 API
update (not yet fully finalized though). glutInitDisplayMode for
example. Improved portability and a few bug fixes.


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Q32: I installed SGI's Cosmo3D beta and GLUT, and I'm having problems
compiling GLUT programs. What gives?

A32: Unfortunately, SGI's Cosmo3D beta images install a DSO for GLUT
(libglut.so) that does not fully implement the GLUT API and lacks
some of the newer GLUT 3.4 entrypoints as well. The problem is
that a DSO takes preferenc over an archive when you compile with
an option like "-lglut". While the Cosmo3D beta installs a
libglut.so, my GLUT distribution and images only build and
install an archive. There are a couple of solutions:

1) Explicitly link your GLUT programs with libglut.a (the
archive version of GLUT). For example, put "/usr/lib/libglut.a"
on your compile line instead of "-lglut".

2) You can convert the GLUT 3.4 archive into a DSO:

su
cd /usr/lib
mv libglut.so libglut.so.cosmo
cc -32 -o libglut.so -shared -all libglut.a
cd /usr/lib32
mv libglut.so libglut.so.cosmo
cc -n32 -o libglut.so -shared -all libglut.a

The new DSO generated from the GLUT 3.4 DSO should be
compatible with the old Cosmo version. This will mean that
all the GLUT programs you build will need the libglut.so on
the machine they run on.

3) Remove the Cosmo3D beta.

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Q33: What is new in GLUT 3.5?

A33: The most significant change with GLUT 3.5 is unifying the X
Window System and Win32 versions of GLUT into a single source
code distribution. Henk Kok contributed several cool new demos
(rollercoaster, chess, opengl_logo). All the demos build cleanly
under Win32. Lots of bug fixes. Interesting new OpenGL rendering
techniques are demonstrated in a number of new examples:
movelight, dinoshade, halomagic, rendereps, movelight, shadowfun,
torus_test, underwater, texfont, reflectdino.

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Q34: How do I use the precompiled Win32 GLUT DLLs with Borland compilers?

A34: The "implib" command should let you generate a GLUT.LIB that works
with Borland compilers from the precompiled GLUT.DLL Here is an
example:

C:\>implib C:\GLUT\LIB\GLUT.LIB C:\WINDOWS\SYSTEM\GLUT.DLL

After this, then link C:\GLUT\LIB\GLUT.LIB to your project

Suggested by Carter <carter@extremezone.com>.

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Q35: Are there any C++ wrappers for GLUT?

A35: Yes, George Stetten (stetten@acpub.duke.edu) of Duke University has
made available the GlutMaster C++ wrapper classes. See:

http://www.duke.edu/~stetten/GlutMaster/GlutMaster.html
http://www.duke.edu/~stetten/GlutMaster/README.txt

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Q36: How do you avoid the Console window appearing when you compiler a
Win32 GLUT application with Microsoft compilers?

A36: Try using the following Microsoft Visual C compiler flags:

/SUBSYSTEM:WINDOWS /ENTRY:mainCRTStartup

These are linker options... if main or wmain are defined, MSVC
build a CONSOLE app by default; hence the need for
/SUBSYSTEM:WINDOWS. if /SUBSYSTEM:WINDOWS is defined, MSVC
expects WinMain or wWinMain to be defined; hence the need to
/ENTRY:mainCRTStartup (eg the entry point is the usual C main).

stdout/stderr are [apparently] not "attached"; output via printf
is simply "eaten" unless redirected at the command-line or by a
parent program.

Information thanks to Jean-David Marrow (jd@riverbed.com).

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Q37: What is new in GLUT 3.6?

A37: GLUT 3.6 adds/improves the following:

o Win32 GLUT performance improvements.

o Win32 GLUT confromance improvements.

o Linas Vepstas's GLE Tubing & Extrusions Library is
included with GLUT, including nroff man pages and
demo programs.

o More GLUT-based OpenGL demos and examples (and bug
fixes to existing demos and examples).

o glutPostWindowRedisplay and glutPostWindowOverlayRedisplay
entry points added for posting redisplays on non-current
windows (for faster multi-window updates).

o Bug fixes and minor functionality improvements to Tom Davis's
micro-UI GLUT-based user interface toolkit.

See the "CHANGES" file that accompanies GLUT 3.6 for a fuller
list of changes.

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Q38: On my IRIX 6.3 SGI O2 workstation, why do I get errors about
"glXChannelRectSyncSGIX" being unresolved building certain GLUT
examples?

A38: The original IRIX 6.3 release for the O2 workstation accidently
advertised support for the dynamic video resize extension supported
on SGI's high-end InfiniteReality graphics system. This confuses
GLUT into providing its dynamic video resize sub-API.

This problem is fixed by patch 1979 (and its successor patches).
Because patch 1979 (and its successor patches) also help O2's
OpenGL rendering performance, I strongly recommend requesting
the latest O2 OpenGL patch from SGI customer support.

Once the patch is installed, your build errors will be resolved.

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Q39: Using GLUT with Microsoft OpenGL 1.1 and compiling GLUT with
Borland compilers causes GLUT applications to generates floating
point exceptions. What can be done?

A39: Under certain conditions (e.g. while rendering solid surfaces
with lighting enabled) MS libraries cause some illegal operations
like floating point overflow or division by zero. The default
behaviour of Microsoft compilers is to mask (ignore) floating
point exceptions, while Borland compilers do not. A function of
Borland run-time library allows to mask exceptions. Modify
glut_init.c by adding the following lines to the function
__glutOpenWin32Connection.

#ifdef __BORLANDC__
#include <float.h>
_control87(MCW_EM,MCW_EM);
#endif

With this modification, compiling the GLUT library with your
Borland compilers and using GLUT with Microsoft OpenGL should
work fine.

GLUT 3.7 will have this change already included in the GLUT
library source code distribution.

This advice comes from Pier Giorgio Esposito (mc2172@mclink.it).

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Q40: Using GLUT with SGI OpenGL for Windows and compiling with
Borland compilers results in linking problems. What can be
done?

A40: Some care must be taken when linking GLUT.DLL or programs
that use it with Borland compilers. The import library
IMPORT32.LIB already contains the functions exported by
the Microsoft OpenGL libraries, thus SGI OpenGL import
libraries must be listed _before_ import32 in the Borland
tlink command line.

This advice comes from Pier Giorgio Esposito (mc2172@mclink.it).

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Q41: What is GameGLUT?

A41: GameGLUT is a set of API extension to GLUT to be released in
GLUT 3.7. These extensions provide keyboard release callbacks,
disabling of keyboard auto repeat, joystick callbacks, and full
screen resolution setting.

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- Mark