| DirectX SDK |
If the user's computer provides no special hardware acceleration for 3-D operations, your application may emulate 3-D hardware in software. RGB devices emulate the functions of color 3-D hardware in software. Because an RGB device is emulated in software, it runs more slowly than a HAL device. However, RGB devices take advantage of any special instructions supported by the user's CPU to increase performance. Supported instruction sets include the AMD 3D-Now! instruction set on some AMD processors and the MMX instruction set supported by many Intel processors. Direct3D uses the 3D-Now! instruction set to accelerate transformation and lighting operations and the MMX instruction set to accelerate rasterization.
Applications written in C++ create an RGB device with the IDirect3D7::CreateDevice method. Pass the value IID_IDirect3DRGBDevice as the first parameter. For more information, see Creating a Direct3D Device.
Applications written in Visual Basic create an RGB device with the Direct3D7.CreateDevice method. Pass the "IID_IDirect3DRGBDevice" string constant as the first parameter. For more information, see Creating a Direct3D Device.