View source for IRIS GL

{{Short description|Graphics API by Silicon Graphics}}
{{Infobox Software|
    name=IRIS GL|
    screenshot=| 
    caption=|
    developer= [[Silicon Graphics]]|
    latest_release_version=[[OpenGL|n/a]]|
    latest_release_date={{start date and age|1992}}|
    operating_system=[[IRIX]]|
    genre=API|
    license=Various proprietary|
    discontinued=[[OpenGL]]
    website={{Official website | http://www.opengl.org }}
}}
'''IRIS GL''' ('''I'''ntegrated '''R'''aster '''I'''maging '''S'''ystem '''G'''raphics '''L'''ibrary) is a proprietary graphics [[application programming interface|API]] created by [[Silicon Graphics]] (SGI) in the early 1980s for producing 2D and 3D computer graphics on their [[IRIX]]-based IRIS graphical workstations.<ref name=seddon>{{cite book|title=OpenGL Game Development|page=43|chapter=History of OpenGL|author=Seddon, Chris|publisher=Wordware|year=2005|isbn=1-55622-989-5|chapter-url=https://books.google.com/books?id=ahb5bqeLROAC&q=IRIS+GL&pg=PA43}}</ref><ref>{{cite web|author=Kilgard, Mark|url=https://www.slideshare.net/Mark_Kilgard/sigraph-asia-2008-modern-opengl-presentation/13-13OpenGLs_PrehistoryIRIS_GL_1Window_system|title=OpenGL Prehistory: IRIS GL (slide from SIGGRAPH talk)|website=www.slideshare.net|year=2008}}</ref> Later SGI removed their proprietary code, reworked various system calls, and released IRIS GL as the industry standard [[OpenGL]].<ref name=seddon/><ref>{{cite web|url=http://www.sgi.com/products/software/opengl/overview.html|title=SGI – OpenGL Overview|archive-url=https://web.archive.org/web/20041031094901/http://www.sgi.com/products/software/opengl/overview.html|archive-date=October 31, 2004|access-date=August 20, 2024|url-status=live}}</ref><ref name="g926">{{cite web|last1=Peddie|first1=Jon|title=Who's the Fairest of Them All?|url=http://www.cgw.com/Publications/CGW/2012/Volume-35-Issue-4-June-July-2012/Who-s-the-Fairest-of-Them-All-.aspx|publisher=Computer Graphics World|access-date=August 20, 2024|date=July 2012}}</ref><ref>{{Cite web|date=July 31, 2006|title=OpenGL ARB to Pass Control of OpenGL Specification to Khronos Group|url=https://www.khronos.org/news/press/opengl_arb_to_pass_control_of_opengl_specification_to_khronos_group|access-date=August 20, 2024|website=The Khronos Group|language=en}}</ref>

== History ==
In 1982, SGI began development of IRIS GL. It soon became much more popular than the ANSI standard [[PHIGS]], as developers considered it more intuitive and flexible. In the years after 1982, IRIS GL began licensing it to many companies, including [[IBM]]. Fragmentation soon became an issue with IRIS GL's popularity, in the implementations and a much bigger one with many different [[windowing system]]s. In 1985, the [[X window system]] came around, and finally there was a somewhat common system. The system was considered more transparent and reliable.<ref name="opengldistilled"/>

Later, a competitor came along from [[Sun Microsystems]] and [[Digital Equipment Corporation]], relying much more on the X window system. It was technically called X3D, though soon became more commonly known as [[PHIGS]] Extension To X (PEX). By the late 1980's, full implementations were available. Around that time, developers that used IRIS GL started to demand a portable, open graphics standard from SGI to support the most machines possible.<ref name="opengldistilled"/>

In 1989, to comply with the demands and not be replaced, SGI started development of [[OpenGL]]. Two years later, the OpenGL ARB was formed with people from many different companies. In September of 1991, it was announced by SGI that IRIS GL was available for general licensing, making it fully open. They also announced that several companies,  including Intel and Microsoft endorsed the GL.<ref>{{cite web |title=SILICON GRAPHICS OPENS IRIS GRAPHICS LIBRARY FOR GENERAL LICENSING |url=http://www.sgistuff.net/hardware/graphics/documents/iris-gl-announce.txt |website=sgistuff.net |access-date=11 March 2025}}</ref>

In June 1992, the OpenGL 1.0 specification was released, with as much portability as possible.<ref name="opengldistilled">{{cite book |last1=Martz |first1=Paul |title=OpenGL Distilled |publisher=Addison-Wesley |date=2006 |url=https://learning.oreilly.com/library/view/opengl-r-distilled/0321336798/ch01.html#ch01lev1sec1 |access-date=1 March 2025}} (free trial)</ref> Unlike PEX, OpenGL did not rely on the window system, it being a completely separate part to ensure their previous goals were met. To avoid namespace conflicts, every function was prefixed with "gl". Many modules were also either cleaned up, removed, or renamed.<ref name="glforx">{{cite book |last1=Kilgrad |first1=Mark |title=OpenGL programming for the X window system |pages=4-5 |date=1996 |publisher=Addison-Wesley |isbn=0201483599 |url=https://archive.org/details/openglprogrammin0000kilg |access-date=1 March 2025}}</ref>

== Overview ==
IRIS GL was a graphics library for the [[IRIX]] workstations. Window creation and input were built in.

It provided special routines for handling 3D graphics, allowing the user to specify a [[3D projection#Perspective projection|3D transformation]], and then having it automatically be applied with every [[Vertex (computer graphics)|vertex]] passed in. Due to the lack of [[shader|programmable shaders]], [[shading]] was specified with many parameters including diffuse, specular, ambient, and emission.

There existed routines like <code>rect</code> that allowed a programmer to specify vertices from a more high-level perspective. 

The GL also had basic [[typesetting]] support using [[raster font]]s, and also support for [[NURBS]] curves<ref>{{cite web |title=Graphics Library Programming Guide |url=https://bitsavers.org/pdf/sgi/iris4d/007-1210-020_Graphics_Library_Programming_Guide_v2.0_May_1990.pdf |website=Bitsavers |publisher=SGI |access-date=12 April 2025 |date=1990}}</ref>

==See also==
* [[Silicon Graphics Image]] for file extension <code>.iris</code>
* [[SGI IRIS]]
* [[IrisVision]] - first port to PCs

==References==
{{reflist}}

== Further reading ==
*{{Cite conference
  | first = James
  | last = Clark
  | title = The Geometry Engine: A VLSI Geometry System for Graphics
  | book-title = Proceedings of the 9th annual conference on Computer graphics and interactive techniques
  | pages = 127–133
  | date = July 1982
  | url = https://design.osu.edu/carlson/history/PDFs/geometry-engine.pdf
  | access-date = 2015-06-08
  | archive-date = 2016-04-02
  | archive-url = https://web.archive.org/web/20160402232433/http://design.osu.edu/carlson/history/PDFs/geometry-engine.pdf
  | url-status = dead
  }}
*{{cite web |title=Graphics Library Programming Guide |url=https://bitsavers.org/pdf/sgi/iris4d/007-1210-020_Graphics_Library_Programming_Guide_v2.0_May_1990.pdf |website=Bitsavers |publisher=SGI |access-date=12 April 2025 |date=1990}}
*{{cite web |title=Graphics Library Reference Manual, C Edition |url=https://bitsavers.org/pdf/sgi/iris4d/007-1203-040_Graphics_Library_Reference_Manual_C_Edition_v4.0_Sep_1990.pdf |website=Bitsavers |publisher=SGI |access-date=12 April 2025 |date=September 1990}}

== External links ==
* [http://www.opengl.org/ Official OpenGL website]
* [https://tech-pubs.net/SGI_Developer/books/OpenGL_Porting/sgi_html/apb.html#id71689 Differences between OpenGL and IRISGL]

[[Category:3D graphics software]]
[[Category:Application programming interfaces]]
[[Category:Graphics libraries]]
[[Category:Graphics standards]]
[[Category:SGI graphics]]
[[Category:Video game development software]]
[[Category:Computer-related introductions in 1992]]