Intel 815 Manuel D’Utilisation
Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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13.8. GFXRENDERSTATE_MAP_FILTER
The Mapping Engine is capable of fetching texels/pixels from at most two maps per pixel. This
instruction specifies the filter settings associated with specified map.
instruction specifies the filter settings associated with specified map.
Figure 35.
State Variable Relationships
Coordinate Sets
Map Information
Blending Stages
Texels
Anisotropic filtering produces superior image quality with reduced performance. Adjusting the LOD bias
can contain the aspect ratio of the filter. Generally the LOD bias should be set to -1.0 when anisotropic
filtering is enabled. The Mip Mode, Min Mode and Mag Mode Filter state variables continue to have
their meanings when anisotropic filtering is enabled.
can contain the aspect ratio of the filter. Generally the LOD bias should be set to -1.0 when anisotropic
filtering is enabled. The Mip Mode, Min Mode and Mag Mode Filter state variables continue to have
their meanings when anisotropic filtering is enabled.
The Mip Mode Filter state variable specifies whether mip-mapping is enabled. If so, it also identifies if
the nearest mip map should be used for the texture data or texels between the two nearest maps should be
dithered together when transitioning between maps. LOD dithering provides the ability to offset the map
LOD based on the pixel x,y location. A 4x4 x,y matrix provides values which range from 0 to 15, which
are scaled and then added to the LOD computation.
the nearest mip map should be used for the texture data or texels between the two nearest maps should be
dithered together when transitioning between maps. LOD dithering provides the ability to offset the map
LOD based on the pixel x,y location. A 4x4 x,y matrix provides values which range from 0 to 15, which
are scaled and then added to the LOD computation.
The Min Mode Filter state variable identifies the filtering operation to utilize when the map is minimized
and a texel is smaller than a pixel. When this occurs the either Nearest or Linear filtering is performed. In
Nearest filtering, the texel with coordinates nearest to the desired pixel value is used. In Linear filtering,
a weighted average of a 2-by-2 area of texels surrounding the desired pixel is used.
and a texel is smaller than a pixel. When this occurs the either Nearest or Linear filtering is performed. In
Nearest filtering, the texel with coordinates nearest to the desired pixel value is used. In Linear filtering,
a weighted average of a 2-by-2 area of texels surrounding the desired pixel is used.
The Mag Mode s Filter state variable describes operations where the map is magnified and a texel is
larger than one pixel. In this mode, the finest texture map (LOD 0) is addressed, and the state variable
selects between Nearest and Linear filtering. In Nearest filtering, the texel with coordinates nearest to the
desired pixel value is used. In Linear filtering, a weighted average of a 2-by-2 area of texels surrounding
the desired pixel is used.
larger than one pixel. In this mode, the finest texture map (LOD 0) is addressed, and the state variable
selects between Nearest and Linear filtering. In Nearest filtering, the texel with coordinates nearest to the
desired pixel value is used. In Linear filtering, a weighted average of a 2-by-2 area of texels surrounding
the desired pixel is used.