Yes perhaps you are right. If I use glDrawBuffers directly, it seems to
work (no GL error reported), however glDrawBuffers is not supported by
WebGL 1.0 specs. To use it, one must query for the extension
WEBGL_draw_buffers.
So then I am wondering, what does Emscripten glDrawBuffers map to?
On Sunday, August 24, 2014 1:22:14 PM UTC-4, jj wrote:
>
> Oh wait, actually that sounds odd like Alon mentions: Are you calling
> getProcAddress with the name of an extension? That's unexpected, it's only
> supposed to be used for function names that an extension supports. Does
> glfwGetProcAddress("glDrawBuffers") work?
>
>
> 2014-08-24 20:07 GMT+03:00 Alon Zakai <[email protected] <javascript:>>:
>
>> Hmm, looks like we don't support any extensions in our getProcAddress
>> code. It just supports functions. Should it support extensions? I'm not
>> sure which docs to read regarding that.
>>
>> - Alon
>>
>>
>>
>> On Sun, Aug 24, 2014 at 9:46 AM, Jukka Jylänki <[email protected]
>> <javascript:>> wrote:
>>
>>> In Emscripten you have all the GL functions for core spec and extensions
>>> available already statically at compile-time without having to obtain
>>> function pointers. Calling the functions without obtaining pointers is
>>> preferred, since it gives better performance and is generally also simpler.
>>>
>>> If you still want to call the function by querying the pointers e.g. in
>>> order to have a symmetric code path for both native and Emscripten, you
>>> should be able to. Perhaps we are missing support for that
>>> function/extension in glfwGetProcAddress? Try checking the
>>> src/library_gl.js and src/library_glfw.js on how they go through the route
>>> to obtain the function pointers to see what might be off there.
>>>
>>>
>>> 2014-08-24 19:39 GMT+03:00 Robert Goulet <[email protected]
>>> <javascript:>>:
>>>
>>> Hello,
>>>>
>>>> I am trying to get a WebGL extension, namely WEBGL_draw_buffers, using
>>>> glfwGetProcAddress and it always return nullptr. When I list all the
>>>> available extensions of my browser I clearly see that
>>>> WEBGL_draw_buffers is listed, and I am even able to run a demo on a
>>>> web page that make use of it. So why glfwGetProcAddress always returns
>>>> nullptr when used with Emscripten? Is this supposed to work?
>>>>
>>>> Chrome JS console output this error:
>>>> bad name in getProcAddress: WEBGL_draw_buffers | WEBGL_draw_buffers
>>>>
>>>> Also I am not sure if this is needed, but I made sure WebGL draft
>>>> extensions are enabled in Chrome.
>>>>
>>>> Or maybe glDrawBuffers is already mapped to WEBGL_draw_buffers when
>>>> used in Emscripten? Can anyone confirm/deny this?
>>>>
>>>> Thank you!
>>>>
>>>> --
>>>> You received this message because you are subscribed to the Google
>>>> Groups "emscripten-discuss" group.
>>>> To unsubscribe from this group and stop receiving emails from it, send
>>>> an email to [email protected]
>>>> <javascript:>.
>>>> For more options, visit https://groups.google.com/d/optout.
>>>>
>>>
>>> --
>>> You received this message because you are subscribed to the Google
>>> Groups "emscripten-discuss" group.
>>> To unsubscribe from this group and stop receiving emails from it, send
>>> an email to [email protected]
>>> <javascript:>.
>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "emscripten-discuss" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to [email protected] <javascript:>.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
>
--
You received this message because you are subscribed to the Google Groups
"emscripten-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/d/optout.
