Glide API
Encyclopedia
Glide is a 3D graphics API
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...

 developed by 3dfx Interactive for their Voodoo Graphics 3D accelerator
Graphics processing unit
A graphics processing unit or GPU is a specialized circuit designed to rapidly manipulate and alter memory in such a way so as to accelerate the building of images in a frame buffer intended for output to a display...

 cards. Although it originally started as a proprietary API, it was later open sourced by 3dfx. It was dedicated to gaming performance, supporting geometry and texture mapping primarily, in data formats identical to those used internally in their cards. The Voodoo cards were the first to offer performance to really make 3D games work well, and Glide became widely used as a result. Further refinement of Microsoft's Direct3D
Direct3D
Direct3D is part of Microsoft's DirectX application programming interface . Direct3D is available for Microsoft Windows operating systems , and for other platforms through the open source software Wine. It is the base for the graphics API on the Xbox and Xbox 360 console systems...

 and full OpenGL
OpenGL
OpenGL is a standard specification defining a cross-language, cross-platform API for writing applications that produce 2D and 3D computer graphics. The interface consists of over 250 different function calls which can be used to draw complex three-dimensional scenes from simple primitives. OpenGL...

 implementations from other graphics card vendors, in addition to growing competition in 3D hardware, eventually caused Glide to become superfluous.

API

Glide is based on the basic geometry and "world view" of OpenGL. OpenGL is a large graphics library with 336 calls in the API, many of which are of limited use. Glide was an effort to select primarily features that were useful for real-time rendering of 3D games. The result was an API that was small enough to be implemented entirely in late-1990s hardware. However, this focus led to various limitations in Glide, such as a 16-bit color depth
Color depth
In computer graphics, color depth or bit depth is the number of bits used to represent the color of a single pixel in a bitmapped image or video frame buffer. This concept is also known as bits per pixel , particularly when specified along with the number of bits used...

 limit in the display buffer
Framebuffer
A framebuffer is a video output device that drives a video display from a memory buffer containing a complete frame of data.The information in the memory buffer typically consists of color values for every pixel on the screen...

.

Use in games

The combination of the hardware performance of Voodoo Graphics (Voodoo 1) and Glide's easy-to-use API resulted in Voodoo cards generally dominating the gaming market during the latter half of the 1990s. The name Glide was chosen to be indicative of the GL underpinnings, while being different enough to avoid trademark
Trademark
A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

 problems.

Glide wrappers and emulators

Glide emulator development has been in progress since the late 1990s. During 3dfx's lifetime, the company was aggressive at trying to stop these attempts to emulate their proprietary API, shutting down early emulation projects with legal threats. However, just before it ceased operations and had its assets purchased by NVIDIA
NVIDIA
Nvidia is an American global technology company based in Santa Clara, California. Nvidia is best known for its graphics processors . Nvidia and chief rival AMD Graphics Techonologies have dominated the high performance GPU market, pushing other manufacturers to smaller, niche roles...

, 3dfx released the Glide API, along with the Voodoo 2 and Voodoo 3 specifications, under an open source license, which later evolved into an open source project. Although no games released after 1999 depend on Glide for 3D acceleration (Direct3D and OpenGL are used instead), Glide emulation is still needed to run older games in hardware accelerated mode. With the specifications and code now open source, there are several capable emulators and wrappers available allowing older games that make use of the Glide API to run on non-Voodoo hardware. Other projects like Glidos
Glidos
The word Glidos comes from the first part of the phrase "Glide API" and the word DOS. Paul Gardiner wrote this small Win9x/XP/Vista application to allow old games written for DOS using the 3dfx proprietary Glide driver to be played on and thus take advantage of the power in newer computer...

allow even older games to use Glide.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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