Intel 815 Manuel D’Utilisation
Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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13.10. GFXRENDERSTATE_MAP_LOD_CONTROL
The Level-of-Detail dither weight and bias can be associated with each map using the following
instruction.
instruction.
Figure 37.
State Variable Relationships
Coordinate Sets
Map Information
Blending Stages
Texels
Dword Bit
Description
0 31:29
Client : 03h – Rendering Engine
28:24
3DState16 : 1Ch
23:19
Opcode : 4h
18:17
Reserved: 00h (Additional Maps)
16
Update Map Index : The valid range is 0–1.
15:11
Reserved: 00h
10
Texture LOD Dither Weight Mask : 0 = Do not update; 1 = Update
9:8
Texture LOD Dither Weight: A 4-bit dither value can be added to the computed and
biased LOD which softens the transitions between mip-maps. The position or weight of
the dither value is specified as follows:
biased LOD which softens the transitions between mip-maps. The position or weight of
the dither value is specified as follows:
00 = Full dither weight (the dither value has a range of 0.0 – 0.9375)
01 = ½ dither weight (the dither value has a range of 0.0 – 0.4375)
10 = ¼ dither weight (the dither value has a range of 0.0 – 0.1875)
11 =
1
/
8
dither weight (the dither value has a range of 0.0 – 0.0625)
7
Texture LOD Bias Mask : 0 = Do not update; 1 = Update
6:0
Texture LOD Bias : This is a signed value that is added to the LOD when the LOD is
determined at a textured pixel. This 2’s complement fixed point value has 2 integer bits
and 4 fractional bits and is signed extended before being added to the LOD. Valid data
value range from -4.0 to 3.9375. (S2.4) The default value is 0.
determined at a textured pixel. This 2’s complement fixed point value has 2 integer bits
and 4 fractional bits and is signed extended before being added to the LOD. Valid data
value range from -4.0 to 3.9375. (S2.4) The default value is 0.