OpenGL ES 3.0 / core desktop GL way of retrieving extension information

[mosra]

In OpenGL ES 3.0 (and GL 3.0+) it is possible to retrieve extension list like this:

GLint count;
glGetIntegerv(GL_NUM_EXTENSIONS, &count);
for(int i = 0; i != count; ++i)
    extensions.add(glGetStringi(GL_EXTENSIONS, i));

Looking at the current code in library_gl.js it looks like WebGL is indeed providing the extension list as an array, but the code then joins it to one large string to support ES2/GL2.1 usage via glGetString(GL_EXTENSIONS). Would it be possible to support also the above usage for better compatibility with ES 3.0 code that's being ported to WebGL 2?

One reason glGetStringi() is used instead of the original glGetString(GL_EXTENSIONS) is that the original way is no longer available in core desktop OpenGL and thus using it harms portability.

Thank you!

[juj]

Your comments are accurate, this is a feature we haven't implemented yet. For GLES3/WebGL2 support we will have to implement that form of extension querying. However this will not be available when targeting GLES2/WebGL1, although that is probably not a concern for you?

[mosra]

I still need to use glGetString(GL_EXTENSIONS) in GLES2/WebGL1 path to stay compatible with native GLES2 implementations, so yes, that's not a concern for me.

[gouletr]

Bump, I'm running into the same issue. Would prefer to have glGetStringi available if this is possible. Thanks!

[juj]

@gouletr: Are you building a WebGL2/GLES3 targeting application? Native GLES2/WebGL1 does not have the function glGetStringi.

[gouletr]

Yes, we are targeting WebGL2/GLES3.

[gouletr]

@juj Thanks for the fix! I will use it right away! 👍

[mosra]

@juj Awesome! Thank you! 👍

[juj]

This was merged in the above PR.