View Full Version : GLSL and MacOS 10.4--no acceleration?
I'm new to GLSL, and I have indications that there is currently no hardware acceleration for shaders written in GLSL.
Is this true? All the shaders that I wrote using Apple's Shader Builder required the software renderer, but I was under the impression it was because my hardware didn't support fragment shading.
A more general question: is there *anyplace* where one can look up the current status of GLSL/OpenGL support under OSX? Having some sort of timeline or roadmap from Apple would help me immensely.
If you want it to work now, use Windows XP.
If you want to wait for Apple to get it right, prepare to wait until long after Apple brings Intel to its rescue and starts selling Intel based Macs - and that's many months away still.
And ofcourse by then, the whole industry will have moved forward and your product would be out-of-date.
08-01-2005, 10:21 PM
I think Tiberius is a little pessimistic here :)
Mac OS X does not currently accelerate GLSL on any hardware. Apple have said that it is a "high priority" for them, but they never discuss specifics of the future. Information about "when" and "how well" is simply not available.
If you want a working hardware-accelerated GLSL implementation now, you have a choice between Windows XP or Linux. You'll find discussions of ATI's Linux support elsewhere here, but I can vouch for the quality of NVidia's drivers on both Windows and Linux.
I don't see the switch to Intel as being at all relevant here. Apple still won't be able to use the Windows or Linux drivers, so we'll be in exactly the same situation we are now.
08-02-2005, 12:13 AM
Yes, MacOS X is not the platform of choice for getting the latest OpenGL enhancements (like OpenGL 2.0, FBO, complete nVidia support (GL_NV_vertex_program3), even for hardware support (all shipping Macs are still using AGP and with the Intel shift, don't expect PCI Express until 2006/2007 ...).
But it is just fine if you plan to do OpenGL 1.5 only stuff, it's way to go. ARB_vertex_program and ARB_fragment_program are your friends here.
As said the parent post, probably GLSL will be supported in hardware in a future OS update, probably in a limited form, and I predict a lot of problems already -
GLSL is complex : ATI and nVidia took almost a year to fine tune their implementations, and since they are using a completly different codebase compared to PC, their might be some differences between PC and Mac for the same GLSL code.
Also Apple has no public roadmap, even for hardware, or OpenGL beta test program or public bug lists or list of bug fixes when they release an OS update.
08-05-2005, 06:56 PM
Originally posted by <Josh Senecal>:
is there *anyplace* where one can look up the current status of GLSL/OpenGL support under OSX?My GLInfo (http://homepage.mac.com/arekkusu/bugs/GLInfo.html) page has the current info.
To use GLSL, you need either OpenGL 2.0, or ARB_shading_language_100 + ARB_shader_objects + ARB_vertex_shader + ARB_fragment_shader. As of today under 10.4.2, that combination is only supported in the software renderer.
Originally posted by execom_rt:
Also Apple has no public roadmap, even for hardware, or OpenGL beta test program or public bug lists or list of bug fixes when they release an OS update.There is no public roadmap, but there is a beta program for registered ADC members. See this post (http://lists.apple.com/archives/mac-opengl/2005/Aug/msg00027.html) for details. (The archive strips the email address, the seed address is firstname.lastname@example.org)
There were bug fix lists (http://developer.apple.com/qa/qa2001/qa1258.html) posted during Jaguar. Hopefully they will be continued.
08-06-2005, 03:22 AM
Thanks for the precisions about the Apple OpenGL seed program.
Alas, few persons are aware about that : It's even not shown in the ADC page, they could update it or improve it, add a 'wishlist' box and give mail addresses. It prooves how weak the Apple developer support is.
According an public Apple OpenGL mailing list (linked in parent post), it's seems that FBO, PBO and GLSL hw is on the works, which sounds good.
09-15-2005, 08:36 AM
i am confused now....
OpenGL Shading Language
The Macintosh implementation of OpenGL supports ARB_shading_language_100, a higher-level language, accessible in C, that lets you leverage the power of the Macintosh hardware to produce advanced image effects. The shading language has its own programming discipline; "Chapter 6, “Further Information”," points you to the applicable documentation.
all illusion - only available in software render?? don't understand apples politics here..
09-16-2005, 12:11 AM
I think, from their posturing before 10.4, that they intended to have it for the 10.4.0 release (at least originally), but it's definitely not yet supported in hardware :)
I feel your pain too. Think Apple is lagging.
My response to the problem is to use NVidia's CG stuff. Set the profile on the compiled program to use ARB_vertex_program and ARB_fragment_program. ( arvp1/arfp1 profiles ) CG has similar syntax to opengl shading language.
When Apple is done with its implementation then I'll migrate over. The language is similar to GLSL. So, now you can do cross platform shading on windows also with the same implementation and code base.
CG also works on my ATI card. Its really cross platform.
Though, I'd prefer to use the opengl standard. See how Apple lagging is effecting developer behavior? If we can't all get along then I have to use CG. :p
09-17-2005, 03:26 AM
cg is pretty cool but it's a shame that apple (in my opinon best software company) is so slow with opengl and developer support
let us tell this apple...
Ya, it makes me nervous going with a non standard solution. But The reality is its my only choice. Developing on the mac is difficult ... all the tools are on the windows boxes. eg. render monkey etc.
Sort of reminds me of hardware development ... all the tools are on windows.
Funny, cgfx also works on my mac which makes CG more interesting. Downloading the latest CG release has a working cgfx example in it.
I tend to use display lists. So, if you call CG at run time in a display list I'm not sure that is going to work.
QuickDraw3D comes to mind when it comes to 3d and Apple. Though, one would think Steve Jobs being associated with Pixar, Apple would have a great OpenGL implementation.
I wonder if they even know they have a problem?
i think they know..if not, how could we tell them?
09-21-2005, 09:44 PM
They've said before, think of filing a bug report as a "vote". The more bug reports they get on each issue, the higher priority they give that issue.
That includes feature request bugs, of course.
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