| DirectX SDK | 
The CONST_D3DTEXTUREMAGFILTER enumeration defines texture magnification filtering modes for a texture stage.
Enum CONST_D3DTEXTUREMAGFILTER
    D3DTFG_POINT        = 1  
    D3DTFG_LINEAR       = 2  
    D3DTFG_FLATCUBIC    = 3  
    D3DTFG_GAUSSIANCUBIC= 4  
    D3DTFG_ANISOTROPIC  = 5  
End Enum
You set a texture stage's magnification filter by calling the Direct3DDevice7.SetTextureStageState method with the D3DTSS_MAGFILTER value as the second parameter, and one of constants of this enumeration as the third parameter.
CONST_D3DTEXTUREMINFILTER, CONST_D3DTEXTUREMIPFILTER, Texture Filtering