|Original author(s)||Khronos Group|
|Stable release||3.1 / March 17, 2014|
|License||free of charge, royalty or licensing|
OpenGL for Embedded Systems (OpenGL ES or GLES) is a subset of the OpenGL computer graphics rendering application programming interface (API) for rendering 2D and 3D computer graphics such as those used by video games, typically hardware-accelerated using a graphics processing unit (GPU). It is designed for embedded systems like smartphones, computer tablets, video game consoles and PDAs.
Several versions of the OpenGL ES specification now exist. OpenGL ES 1.0 is drawn up against the OpenGL 1.3 specification, OpenGL ES 1.1 is defined relative to the OpenGL 1.5 specification and OpenGL ES 2.0 is defined relative to the OpenGL 2.0 specification. This means that, for example, an application written for OpenGL ES 1.0 should be easily portable to the desktop OpenGL 1.3; as the OpenGL ES is a stripped-down version of the API, the reverse may or may not be true, depending on the particular features used.
Version 1.0 and 1.1 both have common and common lite profiles, the difference being that the common lite profile only supports fixed-point instead of floating point data type support, whereas common supports both.
OpenGL ES 1.0
OpenGL ES 1.0 contained much functionality stripped from the original OpenGL API and a little bit added. One significant difference between OpenGL and OpenGL ES is that OpenGL ES removed the need to bracket OpenGL library calls with
glEnd. Other significant differences are that the calling semantics for primitive rendering functions were changed in favor of vertex arrays, and fixed-point data types were introduced for vertex coordinates. Attributes were also added to better support the computational abilities of embedded processors, which often lack a floating point unit (FPU). Many other functions and rendering primitives were removed in version 1.0 to produce a lightweight interface, including:
- quad and polygon rendering primitives,
- texgen, line and polygon stipple,
- polygon mode and antialiased polygon rendering are not supported, although rendering using multisample is still possible (rather than alpha border fragments),
ARB_Imagepixel class operation are not supported, nor are bitmaps or 3D textures,
- several of the more technical drawing modes are eliminated, including frontbuffer and accumulation buffer. Bitmap operations, specifically copying pixels (individually) is not allowed, nor are evaluators, nor (user) selection operations,
- display lists and feedback are removed, as are push and pop operations for state attributes,
- some material parameters were removed, including back-face parameters and user defined clip planes.
OpenGL ES 1.1
OpenGL ES 1.1 added features such as mandatory support for multitexture, better multitexture support (including combiners and dot product texture operations), automatic mipmap generation, vertex buffer objects, state queries, user clip planes, and greater control over point rendering.
OpenGL ES 2.0
OpenGL ES 2.0 was publicly released in March 2007. It is based roughly on OpenGL 2.0, but it eliminates most of the fixed-function rendering pipeline in favor of a programmable one in a move similar to transition from OpenGL 3.0 to 3.1. Control flow in shaders is generally limited to forward branching and to loops where the maximum number of iterations can easily be determined at compile time. Almost all rendering features of the transform and lighting stage, such as the specification of materials and light parameters formerly specified by the fixed-function API, are replaced by shaders written by the graphics programmer. As a result, OpenGL ES 2.0 is not backward compatible with OpenGL ES 1.1. Some incompatibilities between the desktop version of OpenGL and OpenGL ES 2.0 persisted until OpenGL 4.1, which added the
OpenGL ES 3.0
The OpenGL ES 3.0 specification was publicly released in August 2012. OpenGL ES 3.0 is backwards compatible with OpenGL ES 2.0, enabling applications to incrementally add new visual features to applications. OpenGL 4.3 provides full compatibility with OpenGL ES 3.0.
New functionality in the OpenGL ES 3.0 specification includes:
- multiple enhancements to the rendering pipeline to enable acceleration of advanced visual effects including: occlusion queries, transform feedback, instanced rendering and support for four or more rendering targets,
- high quality ETC2 / EAC texture compression as a standard feature, eliminating the need for a different set of textures for each platform,
- a new version of the GLSL ES shading language with full support for integer and 32-bit floating point operations;
- greatly enhanced texturing functionality including guaranteed support for floating point textures, 3D textures, depth textures, vertex textures, NPOT textures, R/RG textures, immutable textures, 2D array textures, swizzles, LOD and mip level clamps, seamless cube maps and sampler objects,
- an extensive set of required, explicitly sized texture and render-buffer formats, reducing implementation variability and making it much easier to write portable applications.
OpenGL ES 3.1
- Compute shaders
- Independent vertex and fragment shaders
- Indirect draw commands
OpenGL ES 3.1 is backward compatible with OpenGL ES 2.0 and 3.0, thus enabling applications to incrementally incorporate new features.
OpenGL ES 1.0
OpenGL ES 1.0 added an official 3D graphics API to the Android and Symbian operating systems, as well as by QNX It is also supported by the PlayStation 3 as one of its official graphics APIs (the other one being low level libgcm library) with Nvidia's Cg in lieu of GLSL. The PlayStation 3 also includes several features of the 2.0 version of OpenGL ES.
OpenGL ES 1.1
The 1.1 version of OpenGL ES is supported by:
- Android 1.6
- Apple iOS for iPad, iPhone, and iPod Touch
- RIM's BlackBerry 5.0 operating system series (only BlackBerry Storm 2, BlackBerry Curve 8530 and later models have the needed hardware)
- BlackBerry PlayBook
- BlackBerry BB10
- The Palm webOS, using the Plug-in Development Kit
- Nintendo 3DS
OpenGL ES 2.0
- The Android platform since Android 2.0 through NDK and Android 2.2 through Java
- Apple iOS 5 or later in iPad, iPad Mini, iPhone 3GS or later, and iPod Touch 3rd generation or later
- BlackBerry devices with BlackBerry OS 7.0 and Blackberry 10, as well as the BlackBerry PlayBook
- Google Native Client
- Various Nokia phones (such as Symbian^3 based Nokia N8 and Maemo based Nokia N900)
- Palm webOS, using the Plug-in Development Kit
- The Pandora console
- The Raspberry Pi
- The Odroid
- Various Samsung mobile phones (such as the Wave)
- Web browsers (WebGL)
- The Ouya video game console
- The GCW-Zero console
OpenGL ES 3.0
- Android since version 4.3, on devices with appropriate hardware and drivers, including:
- BlackBerry 10 OS version 10.2 in BlackBerry Z30.
- Adreno 3xx and 4xx series (Android, Windows Phone 8, Windows RT)
- Mali T6xx series (Android, Linux, Windows 7)
- PowerVR Series6 (iOS, Linux)
- Vivante (Android, OS X 10.8.3, Windows 7)
- Nvidia (Android, Linux, Windows 7)
- Intel (Linux)
- Khronos Releases OpenGL ES 3.1 Specification
- "Khronos Press Releases - OpenGL ES 2.0". Khronos.org. 2007-03-05. Retrieved 2010-12-23.
- Edward Angel, Dave Shreiner, Interactive Computer Graphics: A Top-Down Approach with Shader-Based OpenGL, 6th Edition, p. xxi-xxii, ISBN 978-0-13-254523-5
- "The OpenGL® ES Shading Language". Khronos.org. Retrieved 2013-02-16.
- "The OpenGL ES 3.0 specification".
- "Khronos Releases OpenGL ES 3.0 Specification to Bring Mobile 3D Graphics to the Next Level". Khronos.org. 2012-08-06. Retrieved 2012-08-06.
- "The OpenGL ES 3.0 Shading Language Online Reference Pages".
- "The OpenGL ES 3.1 specification".
- "Khronos Releases OpenGL ES 3.1 Specification". Khronos.org. 2014-03-17. Retrieved 2014-03-17.
- What is Android?, Google
- Symbian OS v9.5 product sheet, Symbian
- "Using OpenGL ES". QNX Software Development Platform (v6.5.0). QNX. Retrieved 2011-01-08.
- OpenGL ES demo in PPT format
- SONY/Khronos OpenGL ES/PSGL Presentation in PPT format
- "New in this beta release". Release Notes - BlackBerry Java Application. Research in Motion. Retrieved 2009-12-08.
- Koh, Damian (2009-11-29). "What to expect for BlackBerry smartphones". CNET Asia. Retrieved 2009-12-08.
- "PDK - Overview". HP Palm Developer Center. Retrieved 2010-12-23.
- "DMP announces OpenGL ES 1.1 conformant PICA 200 adopted by Nintendo". 2010-06-21. Retrieved 2013-06-02.
- "Android 2.2 specifications". Google. 2010-07-01.
- "Maemo software - Nokia > Nokia N900 mobile computer > Technical specifications". Nokia Corporation. Retrieved 12 January 2010.
- Pulli, Kari; Aarnio, Tomi; Miettinen, Ville; Roimela, Kimmo & Vaarala, Jani (2007). Mobile 3D Graphics with OpenGL ES and M3G. Morgan Kaufmann. ISBN 0-12-373727-3.
- Astle, Dave & Durnil, David. OpenGL ES Game Development. Course Technology PTR. ISBN 1-59200-370-2.
- Pulli, Kari; Aarnio, Tomi; Roimela, Kimmo & Vaarala, Jani. "Designing graphics programming interfaces for mobile devices". IEEE CG&A 2005.
- Munshi, Aaftab; Ginsburg, Dan; Shreiner, Dave. OpenGL(R) ES 2.0 Programming Guide. Addison-Wesley Professional. ISBN 978-0-321-50279-7.
|Wikibooks has a book on the topic of: OpenGL Programming/OpenGL ES Overview|
- Official website
- Public bug tracking
- OpenGL ES Conformant companies
- Public forums
- List of OpenGL ES compatible devices
- The Firefox effort to support 3D based on OpenGL ES with the <canvas> tag
- ANGLE: OpenGL ES 2.0 implementation on top of Direct3D 9
- OpenGL ES 1.1 & 2.0 Emulator from ARM
- OpenGL ES 3.0 Emulator from ARM
- OpenGL ES 3.0 example programs