|Microsoft DirectX 9.0|
Get the filter type that is used for automatically generated mipmap sublevels.
Filter type. See D3DTEXTUREFILTERTYPE. A texture must be created with USAGE_AUTOGENMIPMAP to use this method. Any other usage value will cause this method to return D3DTEXF_NONE.
Changing the filter type "dirties" the mipmap sublevels and causes them to be regenerated.
The (default) filter type set at texture creation time is D3DTEXF_LINEAR. If the driver doesn't support a linear filter, the filter type will be set to D3DTEXF_POINT. All filter types supported by the driver for regular texture filtering are supported for autogeneration except D3DTEXF_NONE. For each resource type, drivers should support all the filter types reported in the corresponding texture, cubetexture, and volumetexture filter caps. For more information about texture types, see D3DTEXTUREFILTERTYPE.
This method has no effect if the texture is not created with D3DUSAGE_AUTOGENMIPMAP. For more information about usage constants, see D3DUSAGE.