From: "W. Kent Starr" <elderburn@...>
Date: 2001-04-29T03:10:55+09:00
Subject: [ruby-talk:14383] Re: Ruby OpenGL question

On Saturday 28 April 2001 09:32, Matthew PATTISON wrote:
> Reply-To:
> I have a question about Yoshi's recently updated OpenGL interface module.
> The README file for the module seemed to be in Japanese, so my installation
> procedure was pretty off the cuff. (I haven't installed any extra modules
> before)
>
> It was:
> copy the file rbogl-0.32.tgz to /usr/lib/ruby/ext (this is where other
> 		extension modules seem to be kept)
>
> type:
> 'tar zxvf rbogl-0.32.tgz'
> 'cd opengl'
> 'ruby extconf.rb'
>
> during which I get the following error message:
> checking for glClear() in -lGL... no
> checking for glClear() in -lMesaGL... no
> "can't create OpenGL module!"
>
> I seemed to get around this by adding:
> $CFLAGS += " -I/usr/X11R6/include/"
> $CFLAGS += " -L/usr/X11R6/lib"
> which represent where the OpenGL libraries and include files can be found.
>
> now 'ruby extconf.rb' succeeds, but
> 'make'
> fails with the errors:
> ....
> glut.c: In function `glut_KeyboardFunc':
> glut.c:147: warning: passing arg1 of `glutKeyboardFunc' from incompatible
> pointer type ....
> gcc -shared		-o glut.so glut.o -lglut -lXmu -lXext -lXi -lGLU -lGL -lX11
> -lXmu -lc /usr/bin/ld: cannot find -lglut
> collect2: ld returned 1 exit status
> make[1]: ***[glut.so] Error 1
> ....
>
> Here I am stuck. Please someone explain to me where I've gone wrong, or
> what the correct procedure is.
>
> Matt


Well, I had a similar probelm with a prior release of Yoshi's OpenGL. There 
is a message in the list archives re this (I am currently archiving 
everything here so can't lay my hands on the ref number now; sorry)

At any rate, there were changes made in the names of certain functions in 
Mesa between versions. By changing a line in Yoshi's code (to preserve any 
other builds of whatever that referenced the new changes) I was able to get 
it to build and run. I suspect you are facing a similar thing (as will I when 
I get aroud to rebuidling Yoshi's new module)

It took a bit of detective work to find these things out BTW :-)

Also, if you are using recent versions of Mesa (I just installed latest 
stable 3.41) the installed lib names are _NOT_ MesaGL and MesaGLU; rather 
these are libGL and libGLU, respectively. (These changes were made, I 
believe, due to Sun's objection to confusion resulting from OpenGL and 
MesaGL; Mesa makes a big deal out of using Mesa and _no_ MesaGL when 
referring to the product). I simply make these changes in the Makefiles of 
respective third party builds.

OTOH if you are planning to create interactive games or 3d virual 
environments, Worlds now has a US patent on such doings. FWIW.

If needed, I will have more info on current situation after I rebuld Yoshi's 
latest GL lib. Maybe this will happen today and maybe not as I hear rumbles 
re some 'family' thing I will have to do today. Ack! :-)

Hope this helps.

Regards,

Kent Starr
elderburn@mindspring.com