element decides, which driver of an active interface should be used to operate the 3D graphics. By setting its value to 1
the driver will be used according to the table below. By setting its value to 0
an automatically detected driver will be used. The driver selected is used to initialize the 3D mode by the 3D graphics window
command. If the 3D window is not active or if the desired driver has not been found, the element will return the 0. Otherwise the number of the active driver is returned. The driver can be changed even after the 3D window has been activated. A driver can by changed automatically, too, after switching over the full screen mode or after changing the active Windows videomode.
1 HAL (hardware)
2 TnLHal (hardware with transformation and lighting module)
3 REF (reference)
4 RGB (software)
5 MMX (software with the MMX instructions)
6 Ramp (software with MONO lighting, without textures)
The HAL driver is a driver utilizing the hardware support of the videocard. It is the only driver supported in the OpenGL interface. The DirectX 7 interface supports another variation, the TnLHal (The lighting and the transformations of the vertices are implemented by the hardware). In higher DirectX versions this variation is automatically integrated with the HAL driver.
The REF driver is a reference driver using no hardware support. It serves as a comparing driver when developing the hardware driver of the videocard. Because of his low speed it is not suitable for practical use.
The RGB and MMX drivers are software drivers. Some operations are carried out in a simplified manner or they partly use the hardware. They are of use in case of incorrect functionality of the hardware driver, or when the videocard does not support the hardware acceleration. An advantage is the possibility of using multitextures in videocards that do not support this feature. The MMX driver uses the processorís MMX instructions; it is supported in the DirectX 6 and 7 only. The RGB and MMX drivers in the DirectX 3 through 6 support the videomode of 256 colors. This videomode is no more supported by the DirectX 7 interface and its higher versions.
The Ramp driver is a software driver using a simplified lighting operation (This is a mono lighting, only the blue component being used.). In Peterís environment this driver is utilized in a simplified manner, without textures. Thus a high driver speed can be reached, owing to which the driver can serve as an lack driver if no hardware acceleration of the videocard is available, and other software drivers operate too slowly.
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