Support for OpenGLES3 ?

[tbruyelle]

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Hi Andrea,

I currently have a desktop application coded under OpenGL3 [1], and I want to embed it into Mandala [2]. Because the desktop version is based on go-gl/gl, I couldn't use remogatto/opengles2, there was too much changes. So I cloned go-gl/gl and hardly delete the code that doesn't exist in the OpenGLES implementation. I tried first to compile under OpenGLES2 but I finally get stuck because of missing methods about vertex arrays (glBindVertexArray etc...). Indeed those methods are only here since OpenGLES3. So I switched to OpenGLES3 but I still have compilation errors about the same methods.

Si I wonder if Mandala can support OpenGLES3 ?

[1] https://github.com/tbruyelle/gostuff/tree/opengl3/games/mozaik [2] https://github.com/tbruyelle/mozaik

[remogatto]

Is OpenGLES3 widely supported on Android devices?

http://developer.android.com/guide/topics/graphics/opengl.html

This doesn't answer to your specific question... but just wondering before thinking of a possible solution.

[tbruyelle]

Yes I know that, and that's a problem. But currently I'm focusing on running my app on an android device, regardless a wide support.

By the way, I noticed the vertex arrays methods are declared in gl2ext.h, with the OES suffix. So normally I should be able to use OpenGLES2 within my app. But :

$ gotask build android --flags "-a"
# github.com/tbruyelle/gl
/home/tom/android-ndk-r9d/ndk-toolchain/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: $WORK/github.com/tbruyelle/gl/_obj/vertexarray.cgo2.o: in function _cgo_c921059ada17_Cfunc_glBindVertexArrayOES:/home/tom/go/src/github.com/tbruyelle/gl/vertexarray.go:36: error: undefined reference to 'glBindVertexArrayOES'
/home/tom/android-ndk-r9d/ndk-toolchain/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: $WORK/github.com/tbruyelle/gl/_obj/vertexarray.cgo2.o: in function _cgo_c921059ada17_Cfunc_glDeleteVertexArraysOES:/home/tom/go/src/github.com/tbruyelle/gl/vertexarray.go:46: error: undefined reference to 'glDeleteVertexArraysOES'
/home/tom/android-ndk-r9d/ndk-toolchain/bin/../lib/gcc/arm-linux-androideabi/4.6/../../../../arm-linux-androideabi/bin/ld: $WORK/github.com/tbruyelle/gl/_obj/vertexarray.cgo2.o: in function _cgo_c921059ada17_Cfunc_glGenVertexArraysOES:/home/tom/go/src/github.com/tbruyelle/gl/vertexarray.go:56: error: undefined reference to 'glGenVertexArraysOES'
collect2: ld returned 1 exit status
exit status 2
cp: cannot stat ‘bin/linux_arm/myapp’: No such file or directory
exit status 1
cp: cannot stat ‘bin/linux_arm/myapp’: No such file or directory
exit status 1
FAIL        Build the application for the given platforms.
2014/06/03 16:30:21 exit status 1

If you try to reproduce the result, the repo tbruyelle/gl has 2 branches : opengles2 and opengles3, so you can switch from one to another. In the opengles2 branch, the vertex arrays methods are declared with the OES suffix.

[remogatto]

Any chance to replace glBindVertexArray with something else?

[tbruyelle]

Well I'm an OpenGL noob and I don't know how I can replace the usage of vao. The only place where I use it is here. It's a common method which is invoked by all my objects.

BTW, do you know why the project doesn't compile even if I switch to OpenGLES2 and replace the vertex array methods by their OES extension version ?

[remogatto]

Google says this:

https://www.google.it/#q=android+ndk+glBindVertexArrayOES

Is that of any help?

Moreover, I'm using vertex arrays in this way:

https://github.com/remogatto/mandala-examples/blob/master/cube/src/cubelib/cube.go#L188

EDIT: reference to cube.go

[tbruyelle]

Yeah I know that, to enable vertex arrays OES extension, the flag GL_GLEXT_PROTOTYPES must be set. I had to do that even to compile tbruyelle/gl in the opengles2 branch.

See in https://github.com/tbruyelle/gl/blob/opengles2/gl.h

I looked at the version of gl2ext.h in my NDK toolchain, and the flag is the same, so it should work.

[remogatto]

I'll take a look at your code ASAP. BTW, I think that the quickest way to fix the issue is to try avoiding the use of such OES extension.

[tbruyelle]

Ok thank you !

2014-06-06 11:33 GMT+02:00 Andrea Fazzi [email protected]:

I'll take a look at your code ASAP. BTW, I think that the the quickest way to fix the issue is to try avoiding the use of such OES extensions.

— Reply to this email directly or view it on GitHub https://github.com/remogatto/mandala/issues/10#issuecomment-45319089.