The good news: Khronos has published version 4.2 of the OpenGL specification in conjunction with the GL Shading Language version 4.20 specification. The bad news? The open-source Linux graphics drivers are falling hopelessly behind in keeping up-to-date with the latest upstream OpenGL releases and what is supported by the proprietary drivers and those for other operating systems.

The release of OpenGL 4.2 isn’t much of a surprise, it’s coming just around one year after the OpenGL 4.1 specification. The occasion for this release is the SIGGRAPH conference taking place this week in Vancouver, Canada. “The OpenGL 4.2 specification has been defined by the OpenGL ARB (Architecture Review Board) working group at Khronos, and includes the GLSL 4.20 update to the OpenGL Shading Language. The OpenGL 4.2 specification contains new features that extend functionality available to developers and enables increased application performance.”

Key features of OpenGL 4.2 with the GLSL 4.20 specification include:

• Support for shaders with atomic counters and load/store/atomic read-modify-write operations to a single level of a texture.
• Capturing GPU-tessellated geometry and drawing multiple instances of the result of a transform feedback to enable complex objects to be efficiently repositioned and replicated.
• Support for modifying an arbitrary subset of a compressed texture, without having to re-download the whole texture to the GPU for significant performance improvements.
• Support for packing multiple 8 and 16 bit values into a single 32-bit value for efficient shader processing with significantly reduced memory storage and bandwidth.

The Khronos press release announcing OpenGL 4.2 can be found on their web-site. The latest specification can be viewed at the OpenGL Registry.

• READ MORE (Source): [Phoronix] OpenGL 4.2 Specification Published With GLSL 4.20