| DirectX SDK | 
The CONST_D3DTEXTUREMINFILTER enumeration defines texture minification filtering modes for a texture stage.
Enum CONST_D3DTEXTUREMINFILTER
    D3DTFN_POINT        = 1 
    D3DTFN_LINEAR       = 2 
    D3DTFN_ANISOTROPIC  = 3 
End Enum
You set a texture stage's magnification filter by calling the Direct3DDevice7.SetTextureStageState method with the D3DTSS_MINFILTER value as the second parameter, and one of constants of this enumeration as the third parameter.
CONST_D3DTEXTUREMAGFILTER, CONST_D3DTEXTUREMIPFILTER, Texture Filtering