OpenGL - Knowledge (XXG)

2034: 56: 4276: 139: 784: 1084:. Since then, OpenGL has occasionally been extended by releasing a new version of the specification. Such releases define a baseline set of features which all conforming graphics cards must support, and against which new extensions can more easily be written. Each new version of OpenGL tends to incorporate several extensions which have widespread support among graphics-card vendors, although the details of those extensions may be changed. 944: 314: 455:. Extensions may introduce new functions and new constants, and may relax or remove restrictions on existing OpenGL functions. Vendors can use extensions to expose custom APIs without needing support from other vendors or the Khronos Group as a whole, which greatly increases the flexibility of OpenGL. All extensions are collected in, and defined by, the OpenGL Registry. 47: 1392:, using templates to define the properties of an object which would be created with one function call. The object could then be used immediately across multiple threads. Objects would also be immutable; however, they could have their contents changed and updated. For example, a texture could change its image, but its size and format could not be changed. 474:. If multiple vendors agree to implement the same functionality using the same API, a shared extension may be released, using the identifier EXT. In such cases, it could also happen that the Khronos Group's Architecture Review Board gives the extension their explicit approval, in which case the identifier ARB is used. 889:) to hardware manufacturers, and delegated windowing functions to the underlying operating system. With so many different kinds of graphics hardware, getting them all to speak the same language in this way had a remarkable impact by giving software developers a higher-level platform for 3D-software development. 1411:

The final specification proved far less revolutionary than the Longs Peak proposal. Instead of removing all immediate mode and fixed functionality (non-shader mode), the spec included them as deprecated features. The proposed object model was not included, and no plans have been announced to include

1403:

Longs Peak was initially due to be finalized in September 2007 under the name OpenGL 3.0, but the Khronos Group announced on October 30 that it had run into several issues that it wished to address before releasing the specification. As a result, the spec was delayed, and the Khronos Group went into

1384:

Because of OpenGL's use of a state system, objects must be mutable. That is, the basic structure of an object can change at any time, even if the rendering pipeline is asynchronously using that object. A texture object can be redefined from 2D to 3D. This requires any OpenGL implementations to add a

435:

New versions of the OpenGL specifications are released by the Khronos Group, each of which extends the API to support various new features. The details of each version are decided by consensus between the Group's members, including graphics card manufacturers, operating system designers, and general

416:

OpenGL is no longer in active development, whereas between 2001 and 2014, OpenGL specification was updated mostly on a yearly basis, with two releases (3.1 and 3.2) taking place in 2009 and three (3.3, 4.0 and 4.1) in 2010, the latest OpenGL specification 4.6 was released in 2017, after a three-year

1380:

The draft introduced a change to object management. The GL 2.1 object model was built upon the state-based design of OpenGL. That is, to modify an object or to use it, one needs to bind the object to the state system, then make modifications to the state or perform function calls that use the bound

1352:

to address concerns that OpenGL was stagnating and lacked a strong direction. 3Dlabs proposed a number of major additions to the standard. Most of these were, at the time, rejected by the ARB or otherwise never came to fruition in the form that 3Dlabs proposed. However, their proposal for a C-style

926:

project, which was a joint effort with the goal of unifying the OpenGL and Direct3D interfaces (and adding a scene-graph API too). In 1998, Hewlett-Packard joined the project. It initially showed some promise of bringing order to the world of interactive 3D computer graphics APIs, but on account of

884:

One of the restrictions of IRIS GL was that it only provided access to features supported by the underlying hardware. If the graphics hardware did not support a feature natively, then the application could not use it. OpenGL overcame this problem by providing software implementations of features

1416:

in protest. Most complaints revolved around the lack of communication by Khronos to the development community and multiple features being discarded that were viewed favorably by many. Other frustrations included the requirement of DirectX 10 level hardware to use OpenGL 3.0 and the absence of

1364:

The design of GLSL was notable for making relatively few concessions to the limits of the hardware then available. This harked back to the earlier tradition of OpenGL setting an ambitious, forward-looking target for 3D accelerators rather than merely tracking the state of currently available

864:

However, SGI had many customers for whom the change from IRIS GL to OpenGL would demand significant investment. Moreover, IRIS GL had API functions that were irrelevant to 3D graphics. For example, it included a windowing, keyboard and mouse API, in part because it was developed before the

762:

Given the high workload involved in identifying and loading OpenGL extensions, a few libraries have been designed which load all available extensions and functions automatically. Examples include OpenGL Easy Extension library (GLEE), OpenGL Extension Wrangler Library (GLEW) and

1412:

it in any future revisions. As a result, the API remained largely the same with a few existing extensions being promoted to core functionality. Among some developer groups this decision caused something of an uproar, with many developers professing that they would switch to

822:

In the 1980s, developing software that could function with a wide range of graphics hardware was a real challenge. Software developers wrote custom interfaces and drivers for each piece of hardware. This was expensive and resulted in multiplication of effort.

1516:. Compatibility contexts include the previously removed fixed-function APIs, equivalent to the ARB_compatibility extension released alongside OpenGL 3.1, while core contexts do not. OpenGL 3.2 also included an upgrade to GLSL version 1.50. 1395:

To support backwards compatibility, the old state based API would still be available, but no new functionality would be exposed via the old API in later versions of OpenGL. This would have allowed legacy code bases, such as the majority of

1547:

As in OpenGL 3.0, this version of OpenGL contains a high number of fairly inconsequential extensions, designed to thoroughly expose the abilities of Direct3D 11-class hardware. Only the most influential extensions are listed below.

1296:

GLSL 4.30, Compute shaders leveraging GPU parallelism, shader storage buffer objects, high-quality ETC2/EAC texture compression, increased memory security, a multi-application robustness extension, compatibility with OpenGL ES 3.0

1308:

GLSL 4.40, Buffer Placement Control, Efficient Asynchronous Queries, Shader Variable Layout, Efficient Multiple Object Binding, Streamlined Porting of Direct3D applications, Bindless Texture Extension, Sparse Texture Extension

1377:. At the time of its original announcement, Longs Peak was presented as the first major API revision in OpenGL's lifetime. It consisted of an overhaul to the way that OpenGL works, calling for fundamental changes to the API. 2018:

Vulkan, formerly named the "Next Generation OpenGL Initiative" (glNext), is a ground-up redesign effort to unify OpenGL and OpenGL ES into one common API that will not be backwards compatible with existing OpenGL versions.

1890:

supports OpenGL 4.6 for Intel Broadwell and newer. Mesa 20.0 supports AMD Radeon GPUs, while support for Nvidia Kepler+ is in progress. Zink as Emulation Driver with 21.1 and software driver LLVMpipe also support with Mesa

885:

unsupported by hardware, allowing applications to use advanced graphics on relatively low-powered systems. OpenGL standardized access to hardware, pushed the development responsibility of hardware interface programs (

485:

The OpenGL Architecture Review Board released a series of manuals along with the specification which have been updated to track changes in the API. These are commonly referred to by the colors of their covers:

403:

In addition to being language-independent, OpenGL is also cross-platform. The specification says nothing on the subject of obtaining and managing an OpenGL context, leaving this as a detail of the underlying

1479:

OpenGL 3.1 fully removed all of the features which were deprecated in version 3.0, with the exception of wide lines. From this version onwards, it's not possible to access new features using a

428:

announced that OpenGL ES would not have new versions and has since concentrated on development of Vulkan and other technologies. As a result, certain capabilities offered by modern GPUs, e.g.

4308: 1772:

Direct State Access (DSA) – object accessors enable state to be queried and modified without binding objects to contexts, for increased application and middleware efficiency and flexibility.

477:

The features introduced by each new version of OpenGL are typically formed from the combined features of several widely implemented extensions, especially extensions of type ARB or EXT.

857:) were also able to bring to market 3D hardware supported by extensions made to the PHIGS standard, which pressured SGI to open source a version of IRIS GL as a public standard called 1434:

OpenGL 3.0 introduced a deprecation mechanism to simplify future revisions of the API. Certain features, marked as deprecated, could be completely disabled by requesting a

4349: 1620:

Drawing multiple instances of data captured from GPU vertex processing (including tessellation), to enable complex objects to be efficiently repositioned and replicated

1072:

OS uses Vulkan as the native graphics API and requires a Vulkan-conformant GPU. Fuchsia intends to support OpenGL on top of Vulkan by means of ANGLE translation layer.

873:. And, IRIS GL libraries were unsuitable for opening due to licensing and patent issues. These factors required SGI to continue to support the advanced and proprietary 4082: 1623:

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

2596: 1664:

Shader storage buffer objects, allowing shaders to read and write buffer objects like image load/store from 4.2, but through the language rather than function calls.

4408: 1851: 4005: 2614: 1778:

Robustness – providing a secure platform for applications such as WebGL browsers, including preventing a GPU reset affecting any other running applications;

1331:

GLSL 4.60, More efficient geometry processing and shader execution, more information, no error context, polygon offset clamp, SPIR-V, anisotropic filtering

4517: 745:– A cross-platform C++ widget toolkit. It provides many OpenGL helper objects, which even abstract away the difference between desktop GL and OpenGL ES 1775:

Flush Control – applications can control flushing of pending commands before context switching – enabling high-performance multithreaded applications;

1420:

Other sources reported that the community reaction was not quite as severe as originally presented, with many vendors showing support for the update.

3768: 3507: 4542: 3832: 3551: 1781:

OpenGL ES 3.1 API and shader compatibility – to enable the easy development and execution of the latest OpenGL ES applications on desktop systems.

922:

to Microsoft, released on June 12, 1997, calling on the company to actively support OpenGL. On December 17, 1997, Microsoft and SGI initiated the

3177: 432:, are not supported by the OpenGL standard. However, support for newer features might be provided through the vendor-specific OpenGL extensions. 3208: 2259: 3696: 2696: 1357:

or GLslang). Like the assembly-like shading languages it was replacing, it allowed replacing the fixed-function vertex and fragment pipe with

687:– A cross-platform windowing and keyboard-mouse handler; its API is a superset of the GLUT API, and it is more stable and up to date than GLUT 4342: 4179: 4157: 4138: 3067: 2997: 539: 498: 3721: 2678: 2039: 3671: 2740: 2281: 3954: 2861: 1065:

Atypical Games, with support from Samsung, updated their game engine to use Vulkan, rather than OpenGL, across all non-Apple platforms.

3979: 3239: 2236: 700:

Several "multimedia libraries" can create OpenGL windows, in addition to input, sound and other tasks useful for game-like applications

3225: 2640: 2189: 839: 719: 644: 236: 3424: 1438:

from the windowing system. OpenGL 3.0 features could still be accessed alongside these deprecated features, however, by requesting a

1320:

GLSL 4.50, Direct State Access (DSA), Flush Control, Robustness, OpenGL ES 3.1 API and shader compatibility, DX11 emulation features

205:

license for use of the Sample Implementation (SI): This is a Free Software License B closely modeled on BSD, X, and Mozilla licenses.

4251: 4225: 4203: 2100: 904: 582: 559: 514: 322: 243: 188: 3794: 3366: 3031: 4033: 4522: 4335: 4235: 4213: 1005:(port of Quake to OpenGL with a few modifications) released in 1997. The company's first licensed engine with OpenGL support was 893: 604: 100: 927:

financial constraints at SGI, strategic reasons at Microsoft, and a general lack of industry support, it was abandoned in 1999.

4537: 811: 722:– A cross-platform multimedia library with a C++ API and multiple other bindings to languages such as C#, Java, Haskell, and Go 3275: 930:

In July 2006, the OpenGL Architecture Review Board voted to transfer control of the OpenGL API standard to the Khronos Group.

4383: 3813: 3467: 2402: 1594: 1564: 803: 3928: 274:(SGI) began developing OpenGL in 1991 and released it on June 30, 1992. It is used for a variety of applications, including 408:. For the same reason, OpenGL is purely concerned with rendering, providing no APIs related to input, audio, or windowing. 1827: 1794: 1746: 265: 4060: 2813: 3743: 1670: 458:

Each extension is associated with a short identifier, based on the name of the company which developed it. For example,

2388: 4532: 4527: 2163: 2065: 1869: 1702: 1640: 1508:

OpenGL 3.2 further built on the deprecation mechanisms introduced by OpenGL 3.0, by dividing the specification into a

393: 130: 3630: 3577: 2312: 2148: 1617:

Support for shaders with atomic counters and load-store-atomic read-modify-write operations to one level of a texture

1285:

GLSL 4.20, Shaders with atomic counters, draw transform feedback instanced, shader packing, performance improvements

3651: 3531: 2701: 2659: 1971:

devices). The latest version supported for OpenGL is 4.1 from 2011. A proprietary library from Molten – authors of

1069: 397: 3062:. UPC Grau. Arquitectura, urbanisme i edificació (in Spanish). Universitat Politècnica de Catalunya. p. 191. 2618: 4512: 603:(GLU). It provided simple, useful features which were unlikely to be supported in contemporary hardware, such as 1353:

shading language was eventually completed, resulting in the current formulation of the OpenGL Shading Language (

907:

technology). The specification was circulated among a few interested parties – but never turned into a product.

4547: 3258: 2769: 2001: 1983: 1883: 1488: 795: 713: 636: 631:, automatic OpenGL context creation has become a common feature of several game-development and user-interface 448: 353: 352:

number 3553). Although the function definitions are superficially similar to those of the programming language

283: 258: 165: 69: 1978:

There are several projects that attempt to implement OpenGL on top of Vulkan. The Vulkan backend for Google's

4291: 2949: 2555: 3410: 2720: 1461: 1194: 923: 896:(OpenGL ARB), the group of companies that would maintain and expand the OpenGL specification in the future. 655:. A few libraries have been designed solely to produce an OpenGL-capable window. The first such library was 295: 3608: 2000:

on Arm added support for OpenGL 3.3 via GLon12, an open source OpenGL implementation on top DirectX 12 via

4507: 2467: 1894: 1036: 802:

implementation of OpenGL. It can do pure software rendering, and it may also use hardware acceleration on

690: 671:

These toolkits are designed to create and manage OpenGL windows, and manage input, but little beyond that.

656: 600: 545: 429: 271: 3446: 3301: 1544:

OpenGL 4.0 was released alongside version 3.3. It was designed for hardware able to support Direct3D 11.

2047: 1865: 1858: 1786: 1738: 1694: 1632: 1586: 1556: 1397: 1044: 326: 275: 262: 208:

Trademark license for new licensees who want to use the OpenGL trademark and logo and claim conformance.

55: 2706: 4313: 3489: 3160: 2215: 1400:

products, to continue to run while other software could be written against or ported to the new API.

799: 571:

Includes a poster-sized fold-out diagram showing the structure of an idealised OpenGL implementation.

417:

break, and was limited to inclusion of eleven existing ARB and EXT extensions into the core profile.

251: 247: 1705:

processors and newer. (Linux Mesa: Ivy Bridge without stencil texturing, Haswell and newer), Nvidia

2886: 1841: 1821: 1155: 1035:

Khronos has stopped providing support in OpenGL for a number of modern graphics technologies, e.g.

632: 627:

Given that creating an OpenGL context is quite a complex process, and given that it varies between

612: 202: 182: 4103: 3769:"NVIDIA GeForce 397.31 Graphics Driver Released (OpenGL 4.6, Vulkan 1.1, RTX, CUDA 9.2) – Geeks3D" 1908:

version 1803 (April 2018 update) for AMD Radeon HD 7700+, HD 8500+ and newer. Released April 2018.

138: 3327: 3192:"Khronos Drives Evolution of Cross-Platform 3D Graphics with Release of OpenGL 4.1 Specification" 2754: 2682: 1873: 1798: 1750: 1706: 1628: 1582: 1552: 1002: 707: 640: 3349: 3143: 3126: 3095: 2935: 4247: 4221: 4199: 4175: 4153: 4134: 4083:"OpenGL 4.5 released, next-gen OpenGL unveiled: Cross-platform Mantle killer, DX12 competitor" 3884:"google/angle: A conformant OpenGL ES implementation for Windows, Mac, Linux, iOS and Android" 3063: 3057: 2993: 2334: 2118: 2115:– low-overhead, cross-platform 2D and 3D graphics API, the "next generation OpenGL initiative" 1790: 1742: 1698: 1636: 1590: 1560: 1025: 772: 615:. The GLU specification was last updated in 1998 and depends on OpenGL features which are now 578: 555: 535: 510: 494: 2992:. Graphics programming (6. print ed.). Boston, Mass. Munich: Addison-Wesley. p. 6. 2963: 2533: 842:

rendering. By contrast, PHIGS was considered difficult to use and outdated in functionality.

3112: 3013: 2232: 1979: 1845: 846: 827: 783: 628: 405: 357: 291: 195: 83: 3388: 2581: 2193: 1601:

Minimum "maximum texture size" is 16,384 × 16,384 for GPUs implementing this specification.

1080:

The first version of OpenGL, version 1.0, was released on June 30, 1992, by Mark Segal and

918:, which eventually became the main competitor of OpenGL. Over 50 game developers signed an 4502: 4303: 2921: 2654: 1389: 1151: 1006: 866: 850: 345: 333:, although it is possible for the API to be implemented entirely in software running on a 325:

for drawing 2D and 3D graphics. It is designed to be implemented mostly or entirely using

287: 254: 3191: 3276:"Khronos Group Announces Key Advances in OpenGL Ecosystem – Khronos Group Press Release" 4275: 4240: 4193: 3722:"Intel Graphics Driver 25.20.100.6861 Released (OpenGL 4.6 + Vulkan 1.1.103) | Geeks3D" 2167: 1658: 1405: 878: 681:– A cross-platform windowing and keyboard-mouse-joystick handler; is more game-oriented 377: 240: 3209:"Khronos Enriches Cross-Platform 3D Graphics with Release of OpenGL 4.2 Specification" 3178:"Khronos Unleashes Cutting-Edge, Cross-Platform Graphics Acceleration with OpenGL 4.0" 2485: 1230:

GLSL 1.4, Instancing, Texture Buffer Object, Uniform Buffer Object, Primitive restart

943: 4496: 4358: 4298: 4167: 3672:"AMD Adrenalin 18.4.1 Graphics Driver Released (OpenGL 4.6, Vulkan 1.1.70) – Geeks3D" 2664: 1968: 1677: 1051: 886: 874: 742: 652: 425: 369: 302: 95: 3910: 1252:

GLSL 3.30, Backports as much function as possible from the OpenGL 4.0 specification

955: with: more historical background when support was being added. You can help by 4189: 4038: 4006:"Meet Vulkan, the powerful, platform-agnostic gaming tech taking aim at DirectX 12" 2725: 2445: 1964: 1122: 3475: 2907: 2862:"Dota 2 removes OpenGL support, new hero Muerta now live, big update due in April" 1530:

Mesa supports software Driver SWR, softpipe and for older Nvidia cards with NV50.

838:. This was because IRIS GL was considered easier to use, and because it supported 599:

The earliest versions of OpenGL were released with a companion library called the

3833:"The end of OpenGL support, plus other updates Apple didn't share at the keynote" 834:

API became the industry standard, used more widely than the open standards-based

424:

API, released in 2016, and codenamed glNext during initial development. In 2017,

2070: 2059: 1960: 1956: 1868:

and newer (FP64 shaders implemented by emulation on some TeraScale GPUs), Intel

1081: 998: 992: 919: 768: 616: 565: 385: 373: 61: 903:" which included elements such as a scene-graph API (presumably based on their 900: 2817: 2029: 1997: 1936: 1915: 1905: 1686:

Texture views to interpret textures in different ways without data replication

1635:

and newer (FP64 shaders implemented by emulation on some TeraScale GPUs), and

1374: 1274:

GLSL 4.10, Developer-friendly debug outputs, compatibility with OpenGL ES 2.0

767:. Extensions are also loaded automatically by most language bindings, such as 710:– A cross-platform multimedia library with a C API focused on game development 361: 341: 313: 299: 279: 90: 78: 1487:. An exception to the former rule is made if the implementation supports the 4471: 4449: 4444: 4373: 2088: 2082: 1993: 1932: 1928: 1901: 1898: 1709:

and newer. VIRGL Emulation for virtual machines supports 4.3+ with Mesa 20.

1683:

Debug abilities to receive debugging messages during application development

1047: 1018: 1014: 976: 911: 764: 748: 1219:

GLSL 1.3, Texture Arrays, Conditional rendering, Frame Buffer Object (FBO)

4327: 3585: 3059:

Simulación visual de materiales : teoría, técnicas, análisis de casos

1789: