Google I/O 2014: Android Extension Pack Announced

Subject: General Tech, Graphics Cards, Mobile, Shows and Expos | July 7, 2014 - 04:06 AM |
Tagged: tegra k1, OpenGL ES, opengl, Khronos, google io, google, android extension pack, Android

Sure, this is a little late. Honestly, when I first heard the announcement, I did not see much news in it. The slide from the keynote (below) showed four points: Tesselation, Geometry Shaders, Computer [sic] Shaders, and ASTC Texture Compression. Honestly, I thought tesselation and geometry shaders were part of the OpenGL ES 3.1 spec, like compute shaders. This led to my immediate reaction: "Oh cool. They implemented OpenGL ES 3.1. Nice. Not worth a news post."

google-android-opengl-es-extensions.jpg

Image Credit: Blogogist

Apparently, they were not part of the ES 3.1 spec (although compute shaders are). My mistake. It turns out that Google is cooking their their own vendor-specific extensions. This is quite interesting, as it adds functionality to the API without the developer needing to target a specific GPU vendor (INTEL, NV, ATI, AMD), waiting for approval from the Architecture Review Board (ARB), or using multi-vendor extensions (EXT). In other words, it sounds like developers can target Google's vendor without knowing the actual hardware.

Hiding the GPU vendor from the developer is not the only reason for Google to host their own vendor extension. The added features are mostly from full OpenGL. This makes sense, because it was announced with NVIDIA and their Tegra K1, Kepler-based SoC. Full OpenGL compatibility was NVIDIA's selling point for the K1, due to its heritage as a desktop GPU. But, instead of requiring apps to be programmed with full OpenGL in mind, Google's extension pushes it to OpenGL ES 3.1. If the developer wants to dip their toe into OpenGL, then they could add a few Android Extension Pack features to their existing ES engine.

Epic Games' Unreal Engine 4 "Rivalry" Demo from Google I/O 2014.

The last feature, ASTC Texture Compression, was an interesting one. Apparently the Khronos Group, owners of OpenGL, were looking for a new generation of texture compression technologies. NVIDIA suggested their ZIL technology. ARM and AMD also proposed "Adaptive Scalable Texture Compression". ARM and AMD won, although the Khronos Group stated that the collaboration between ARM and NVIDIA made both proposals better than either in isolation.

Android Extension Pack is set to launch with "Android L". The next release of Android is not currently associated with a snack food. If I was their marketer, I would block out the next three versions as 5.x, and name them (L)emon, then (M)eringue, and finally (P)ie.

Would I do anything with the two skipped letters before pie? (N)(O).

GDC 14: OpenGL ES 3.1 Spec Released by Khronos Group

Subject: General Tech, Graphics Cards, Mobile, Shows and Expos | March 17, 2014 - 09:01 AM |
Tagged: OpenGL ES, opengl, Khronos, gdc 14, GDC

Today, day one of Game Developers Conference 2014, the Khronos Group has officially released the 3.1 specification for OpenGL ES. The main new feature, brought over from OpenGL 4, is the addition of compute shaders. This opens GPGPU functionality to mobile and embedded devices for applications developed in OpenGL ES, especially if the developer does not want to add OpenCL.

The update is backward-compatible with OpenGL ES 2.0 and 3.0 applications, allowing developers to add features, as available, for their existing apps. On the device side, most functionality is expected to be a driver update (in the majority of cases).

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OpenGL ES, standing for OpenGL for Embedded Systems but is rarely branded as such, delivers what they consider the most important features from the graphics library to the majority of devices. The Khronos Group has been working toward merging ES with the "full" graphics library over time. The last release, OpenGL ES 3.0, was focused on becoming a direct subset of OpenGL 4.3. This release expands upon the feature-space it occupies.

OpenGL ES also forms the basis for WebGL. The current draft of WebGL 2.0 uses OpenGL ES 3.0 although that was not discussed today. I have heard murmurs (not from Khronos) about some parties pushing for compute shaders in that specification, which this announcement puts us closer to.

The new specification also adds other features, such as the ability to issue a draw without CPU intervention. You could imagine a particle simulation, for instance, that wants to draw the result after its compute shader terminates. Shading is also less rigid, where vertex and fragment shaders do not need to be explicitly linked into a program before they are used. I inquired about the possibility that compute devices could be targetted (for devices with two GPUs) and possibly load balanced, in a similar method to WebCL but no confirmation or denial was provided (although he did mention that it would be interesting for apps that fall somewhere in the middle of OpenGL ES and OpenCL).

The OpenGL ES 3.1 spec is available at the Khronos website.

Source: Khronos