OpenGL is an industrial standard in this area. The computer three-dimensional graphics refers to the technique of converting the three-dimensional space described by the data to convert to a two-dimensional image and displayed or printed.
OpenGL is a library that supports this conversion. It stems from the IRIS GL developed by SGI for its graphics workstation, developing in cross-platform transplantation into OpenGL. SGI issued a version 1.0 version in July 1992, and became an industrial standard, which was controlled by an independent consignment of the independent consortium in 1992. ARB members such as SGI produce standards in voting, and make specific documents announced, and software and hardware vendors have developed their own system. Only the implementation of all the tests of the ARB specification can be called OpenGL. In December 1995, ARB approved 1.1 version, the latest version of the specification was 1.2.1 passed by 1999.5.
OpenGL is designed to be independent of hardware, independent of window system, can be used on various computers running various operating systems, and can work in customer / server mode in network environments, is professional graphics processing, scientific computing and other high-end Standard graphics library in the field. It is MS-Direct3D in its low-end application, which is provided in the form of COM interface, so it is extremely complex, stable, and Microsoft has copyright, currently available on the Windows platform. The advantage of D3D is on the speed, but now the low-cost graphics can provide good OpenGL hardware acceleration, so 3D use Direct3D has no special necessary, and there is currently no Direct 3D technology in professional graphics, especially high-end applications. The foundation example, and the low-end application of the game also has the trend to turn OpenGL.
Microsoft's support in Windows NT begins with 3.51, and supports in Windows 9x begin with Win95 OEM Service Release 2. There are two OpenGL libraries for Windows, and the MS implementation and SGI implementation are automatically detected whether there is an ICD (Install Device DeviceDriver driver that displays the display card manufacturer, which calls the routines in the ICD. Otherwise, the CPU is used to calculate, so the OpenGL acceleration capability of the display card can be used. It is not a difference between the usage method for developers, just if there is an ICD driver. The SGI version is that pure software does not use hardware acceleration and SGI has announced its stop support in 1999, but this library is easy to debug the program, there are still many developers.
SGI has announced the development of OpenGL , the maximum feature of the graphic library is an interim object, providing tree scene support, which greatly reduces the workload of complex scenes using OpenGL. Later (1999) SGI announced the development of Ferihant, the next-generation graphics processing system, including Windows, including DirectX and OpenGL's low graphics processing interface, and advanced interfaces featured by the scene map, and stopped under Windows. OpenGL implementation is determined by determination. This is a world-famous, everyone thinks that Windows graphics will have a happy life, but soon, SGI announces suspension of cooperation, and withdraws the scientists who sent them, Ferihant basically died. SGI said that the reason for the termination of cooperation is that M $ is not willing to actively cooperate. It is ideal that SGI's technology into DirectX, and truly inside. However, it is still a bit of credibility based on the boss of the SGI in the graphic process, because M $ initial support OpenGL is not active.
Although it has already implemented its OpenGL version as early as WinNT3.51, it is refused to provide with its Windows95, saying that the API is suitable for high-end applications, while Win95 is not used for general consumers, and in its Win3. Based on the WING chart library developed by X, the later DirectX library, said that the library is specifically designed for high-performance game development, which is undintereently, this is undoubtedly very reasonable under the hardware conditions. And soon becoming a standard API for game development in a Windows environment. The library is essentially a way to bypass Windows direct access to memory, thereby solving the shortcomings of GDI system performance, but because it is provided in the form of COM interface, it is quite complicated, and stability is not very good. So some people say that Direct3D is used for companies that pursue speed and unscrupulous means. In this period, the three-dimensional graphics acceleration card began to travel to commercial and home, that is, S3 companies accelerated with the three-dimensional graphics, the S3 company accelerated, and the board card has launched a challenge at the time of Trident. . In addition, the real-time three-dimensional game began to popular, and the first person under DOS was shot. In today (2000.4) game circle, no one does not know, is it? 1996.12. IID Software Master John Carmack wrote the following words in its. PLAN in its. PLAN, is written in its .plan: Direct-3D IS A Horribly Broken API. It inflicts Great Pain and Suffering on The Programmers Using It, Without returning any significant advantages. I do not think there is ANY market segment that D3D is apropriate for, OpenGL seems to work just fine for everything from quake to softimage. there is no good technical reason for the existance of D3D. I'm sure D3D WILL SUCK LESS with Each FortComing Version, But this is an Oportunity To Just Bypass Dragging The Entire Development Community THROUGH The Messy Evolution of An Ill-Birthed API.
