| IRIS GL | |
|---|---|
| Developer | Silicon Graphics |
| Stable release | |
| Operating system | IRIX |
| Type | API |
| License | Various proprietary |
IRIS GL (IntegratedRasterImagingSystemGraphicsLibrary) is a proprietary graphicsAPI created bySilicon Graphics (SGI) in the early 1980s for producing 2D and 3D computer graphics on theirIRIX-based IRIS graphical workstations.[1][2] Later SGI removed their proprietary code, reworked various system calls, and released IRIS GL as the industry standardOpenGL.[1][3][4][5]
In 1982, SGI began development of IRIS GL. It soon became much more popular than the ANSI standardPHIGS, as developers considered it more intuitive and flexible. In the years after 1982, IRIS GL began licensing it to many companies, includingIBM. Fragmentation soon became an issue with IRIS GL's popularity, in the implementations and a much bigger one with many differentwindowing systems. In 1985, theX window system came around, and finally there was a somewhat common system. The system was considered more transparent and reliable.[6]
Later, a competitor came along fromSun Microsystems andDigital Equipment Corporation, relying much more on the X window system. It was technically called X3D, though soon became more commonly known asPHIGS 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.[6]
In 1989, to comply with the demands and not be replaced, SGI started development ofOpenGL. 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.[7]
In June 1992, the OpenGL 1.0 specification was released, with as much portability as possible.[6] 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.[8]
IRIS GL was a graphics library for theIRIX workstations. Window creation and input were built in.
It provided special routines for handling 3D graphics, allowing the user to specify a3D transformation, and then having it automatically be applied with everyvertex passed in. Due to the lack ofprogrammable shaders,shading was specified with many parameters including diffuse, specular, ambient, and emission.
There existed routines likerect that allowed a programmer to specify vertices from a more high-level perspective.
The GL also had basictypesetting support usingraster fonts, and also support forNURBS curves[9]
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