Re: [PyOpenGL-Users] Using PyopenGL with GLArea
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Re: [PyOpenGL-Users] Using PyopenGL with GLArea
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From: Matti K. <mat...@gm...> - 2017-03-11 17:15:51
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I forked your gist: https://gist.github.com/matti-kariluoma/7786a620abe87deb54c6012b07ded884 I added error-checking to work around the errors I encountered, and placed a print-statement to show how to check which PyOpenGL Platform is loaded at runtime. When I tried to run either gist on my Nvidia+Debian laptop (pyopengl 3.0.2), the program crashed immediately with an error similar to: http://askubuntu.com/questions/175744/x-error-of-failed-request-badrequest-invalid-request-code-or-no-such-operation When I tried to run your gist on my Intel+Ubuntu 16.10 machine, your gist gives the errors you described. After making my changes, my gist displayed a red triangle with platforms "linux2" and "posix". == > I just dont 100% get why i need to prefix I would not want to tell a user they need todo that PYOPENGL_PLATFORM allows one codebase to support osx, windows, and various linux flavors. A platform is selected at runtime to simplify the distribution of PyOpenGL. Some platforms implement things differently- there will always be bugs or missing functionality when running on different platforms. Avoid the use of `from X import *' to make your code more likely to run on a different platform. Instead of: from OpenGL.GLUT import * glutInit([]) ...try: from OpenGL import GLUT as glut glut.glutInit([]) ... you'd be surprised how much this helps platform portability. Each of the platforms has various dependencies that are not installed when you get pyopengl from source or pip, however the system package manager (apt) will download the dependencies automatically (e.g. freeglut3, etc.) for your system's recommended platform. Some of the "optional" platforms (osmesa, egl) do not have packages in apt, so you'll need to install the dependencies yourself. This becomes very complicated when you use external PPAs, or build your own drivers and libraries! Hint: Use strace to see which drivers/libraries are being used by your process, to ensure you are using the drivers/libraries you intend: $ strace python glutexample.py 2>&1 | grep open == >is there a way i can detect the profiles and select the best on startup ? You can choose between PyOpenGL platforms at runtime by setting `os.environ' in your code: import os os.environ['PYOPENGL_PLATFORM'] = 'posix' import OpenGL ...you /should/ be able to use the `reload' function (http://stackoverflow.com/questions/437589/how-do-i-unload-reload-a-python-module) to choose a different platform at runtime: import os os.environ['PYOPENGL_PLATFORM'] = 'posix' import OpenGL # check if we have the features we want, if not... if reload_opengl_platform: os.environ['PYOPENGL_PLATFORM'] = 'osmesa' reload(OpenGL) I did not test the`reload' code above, your results may vary. On 3/9/17 1:57 PM, Oliver Marks wrote: > I am not sure if this is an issue now there are a few things I have > noticed it occurs when using osmesa on x11 and wayland. > > I can now run it on both with x11 it just works in wayland if i prefix > PYOPENGL_PLATFORM = "EGL" then it works. > > I am using ubuntu 16.10 and python-gobject 3.22.0-1 from the repository. > > > PYOPENGL_PLATFORM = "EGL" > > I have a gi gtkglarea example on stack overflow > http://stackoverflow.com/questions/42185728/why-is-glgenvertexarrays-undefined-in-pyopengl-when-using-gtkglarea. > > > Tried to use Glut which i have never used before but that seems to be > a world of pain and brings up new errors :/ > > - using EGL NotImplementedError: Platform does not define a GLUT font > retrieval function > - using osmesa gives me TypeError: unhashable type contextdata.py", > line 106, in getValue > - using glx gives me glGenVertexArrays(1) this function takes at least > 2 arguments (1 given) > > This is where i got to with the code but it could be completely wrong > as you don't seem to manage context in the same way but i did not find > many glut examples most see to use pygame. > > https://gist.github.com/olymk2/b156f7490e3f5662e2fa0cf42b8c7c63 > > > Anyway my code kind of works I just dont 100% get why i need to prefix > I would not want to tell a user they need todo that, so is there a way > i can detect the profiles and select the best on startup > > > > > > > > > On Wed, Mar 8, 2017 at 3:25 PM Matti Kariluoma > <mat...@gm... <mailto:mat...@gm...>> wrote: > > I will take a look on Saturday. > > 1) In the meantime, could you create a minimal example that > demonstrates the problem? > > Its always very interesting to see simple-looking code that works > on some platforms but doesn't work on others; we just had an > example of such two weeks ago from another user. > > Ideally your minimal example would not involve the use of the `gi' > module, or at the very least, include instructions to bring a > fresh installation up with that package installed, i.e. "sudo > apt-get install ..." > > 2) Does your problem require `gi' for this error to show? > > 3) Is the error reproducible under GLUT or GLFW? > > 4) If (2), what steps are needed to install `gi', and what version > of `gi'? > > On 3/5/17 12:49 PM, Oly wrote: >> Just another thing of note, >> >> using PYOPENGL_PLATFORM = "osmesa" with x11 causes the same >> issue, so it would appear related to the mesa drivers. >> >> What other options can that take, can i enforce nvidia or intel >> instead of osmesa ? >> >> perhaps wayland is defaulting to mesa and x11 is using something >> else. >> >> feels like i am getting nearer to a solution, or at least a work >> around. >> >> >> >> On Sun, 5 Mar 2017 at 17:29 Oly <ol...@gm... >> <mailto:ol...@gm...>> wrote: >> >> Also because it maybe useful, i have this being reported by >> gtk / opengl. >> >> Intel_Open_Source_Technology_Center_4.5_(Core_Profile)_Mesa_17.0.0_-_padoka_PPA_Mesa_DRI_Intel(R)_Kabylake_GT2__4.50 >> OpenGL Version 4.5_(Core_Profile)_Mesa_17.0.0_-_padoka_PPA >> OpenGL Renderer Mesa_DRI_Intel(R)_Kabylake_GT2_ >> Shader Language version 4.50 >> >> so it looks like things should be new enough to support that >> feature under wayland. >> >> >> On Sun, 5 Mar 2017 at 17:28 Oly <ol...@gm... >> <mailto:ol...@gm...>> wrote: >> >> Thanks for the offer not sure how i missed your reply. >> >> Anyway i made some progress, yes my issue is with linux >> and gtk specifically I have also found out it has >> something todo with wayland. >> >> Running the example i can get it to work with my intel >> and nvidia graphics (optimus card) on x11 but if i am >> using wayland then i get the error above. >> >> Not sure why wayland would effect what available to me >> anyone seen anything similar ? >> >> Seems it i graphics card related. >> >> I did not know about this trick >> PYOPENGL_PLATFORM="osmesa" so thats useful to know but it >> does not help unfortunately. >> >> >> On Sun, 12 Feb 2017 at 20:20 Matti Kariluoma >> <mat...@gm... >> <mailto:mat...@gm...>> wrote: >> >> I tried to have a look at your code, but I don't have >> the `gi' package >> on my machine, and `pip install gi' can't find it either. >> >> 1) Would you accept help in the form of a program >> that starts with >> `from OpenGL import GLUT' , or does your problem >> require gi? >> >> As for the error you posted, looking at >> https://mesamatrix.net/ I see >> that glGenVertexArrays is a part of OpenGL 3.0, extension >> GL_ARB_vertex_array_object which seems to have broad >> support. >> >> 2) Maybe your graphics device (or its driver) is ancient? >> >> Since your gist seems to indicate you are using GTK, >> I assume you are >> running this under Linux. You may want to look into >> running PyOpenGL >> under mesa, using one of their software renderers if >> for whatever >> reason you don't have OpenGL3.0 support. >> >> Using the mesa CPU renderer under Linux: >> http://www.mattikariluoma.com/blog/Headless%20Rendered%20OpenGL%20Scenes.html >> >> >From: Oliver Marks <oly@di...> <mailto:oly@di...> - >> 2017-02-11 22:40:09 >> > >> >Thought i would have a stab at trying to make this >> work, I cant find any >> >existing working examples. >> > >> >I have linked a gist if any one want to try. >> > >> >currently I am getting this error. >> > >> >OpenGL.error.NullFunctionError: Attempt to call an >> undefined function >> >glGenVertexArrays, check for bool(glGenVertexArrays) >> before calling >> > >> >Which to me sounds like its not available to the >> context, GLArea is >> >supplying the context so i am unsure why this would be ? >> > >> >Any ideas or can anyone give me some pointers ? >> > >> >https://gist.github.com/olymk2/5b3e49ac83130e580bd9983f2e5d49c3 >> > >> >> ------------------------------------------------------------------------------ >> Check out the vibrant tech community on one of the >> world's most >> engaging tech sites, SlashDot.org! >> http://sdm.link/slashdot >> _______________________________________________ >> PyOpenGL Homepage >> http://pyopengl.sourceforge.net >> _______________________________________________ >> PyOpenGL-Users mailing list >> PyO...@li... >> <mailto:PyO...@li...> >> https://lists.sourceforge.net/lists/listinfo/pyopengl-users >> > > ------------------------------------------------------------------------------ > Announcing the Oxford Dictionaries API! 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