OpenGL atomic counters

Discussion created by aqnuep on Oct 24, 2010
Latest reply on Oct 25, 2010 by pboudier


I've observed that from Catalyst 10.10a the OpenGL driver includes the extension GL_EXT_shader_image_load_store which is great news.

However, the extension mentions atomic counters that would be available via the extension GL_EXT_shader_atomic_counters, but the extension is not present (even though there is an ARB version of the extension in the extensions list).

Anyway, there is no any documentation about GL_ARB_shader_atomic_counters or GL_EXT_shader_atomic_counters and this way we are unable to use them.

I know that GL_EXT_shader_image_load_store enables atomic R/W operations to buffer objects but I suspect that atomic counters are a much faster way in hardware so it would be a great benefit to be able to use it.

The reason why I opened this topic is that I would like to implement Order Independent Transparency (OIT) in OpenGL and even though it would be possible to do it using only GL_EXT_shader_image_load_store, I suppose performance would benefit from dedicated atomic counters.

Can you give us any (even "non-official") specification of the atomic counters extensions?