OpenCL/OpenGL ES interop on Android

Hi Sheri,

1. We are compiling using the ndk (r10d)
2. The supported list of extensions is: cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_byte_addressable_store cl_khr_fp64 cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_gl_sharing cl_khr_egl_event cl_khr_egl_image cl_arm_core_idn

Thanks,

Alex

Hi Sheri,

1. We are compiling using the ndk (r10d)
2. The supported list of extensions is: cl_khr_global_int32_base_atomics cl_khr_global_int32_extended_atomics cl_khr_local_int32_base_atomics cl_khr_local_int32_extended_atomics cl_khr_byte_addressable_store cl_khr_fp64 cl_khr_int64_base_atomics cl_khr_int64_extended_atomics cl_khr_gl_sharing cl_khr_egl_event cl_khr_egl_image cl_arm_core_idn

Thanks,

Alex

Hi Alex,

There are two situations that might cause failure CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR (-1000) when creating cl context from gles context.

1. Invalid current context & display: You mentioned these two are valid, so won't caused by this.

2. Library linking issue: That's why I asked how you build your program. Please make sure -lGLES_mali(-lOpenCL) is before -lEGL -lGLESv2.

Please try again, thanks.

BR,

Sheri

Hi Sheri,

We were using the order -lEGL -lGLESv2 -lOpenCL originally.

Using the original order this gives the CL_INVALID_GL_SHAREGROUP_REFERENCE_KHR error, the context and display were reported by eglGetCurrentContext/eglGetCurrentDisplay as

• Context 2000702920
• Dispay 1

Using the order in your post (-lOpenCL -lEGL -lGLESv2) the error reported is CL_INVALID_PROPERTY since both the context and display are now invalid (both are reported as 0). However, we are still able to draw within the GL context.

Thanks,

Alex

Hi Alex,

Thanks for you feedback, can I ask what is your libOpenCL.so link to, is it directly link to libGLES_mali.so? Please try only link with libGLES_mali.so without libEGL.so and libGLESv2.so.

BR,

Sheri

Hi Sheri,

The symlinks for libOpenCL.so are:

libOpenCL.so -> libOpenCL.so.1

libOpenCL.so.1 -> libOpenCL.so.1.1

libOpenCL.so.1.1 -> /vendor/lib/egl/libGLES_mali.so

Without the -lEGL -lGLESv2 flags the build fails with undefined references for the egl* and gl* functions used in the project (for example eglGetCurrentContext)

Thanks,

Alex

Hi Alex,

That's odd: all the symbols are in libGLES_mali.so so it should work.

Can you try to create a symlink

/system/lib/libGLES_mali.so -> /vendor/lib/egl/libGLES_mali.so

And to link directly against libGLES_mali.so ?

Thanks,

Anthony

Do you get the same issues if you add -lGLES_mali as your first entry?

Kind Regards,

Michael McGeagh

Hi Anthony,

I have pulled libGLES_mali.so off the device, placed it in the ndk lib directory and replaced -lOpenCL -lEGL -lGLESv2 with -lGLES_mali as Michael indicated. This works! The shared context is created without error and CL/GL interop looks to be working.

Thank you all for your help,

Alex