Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

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13.9.GFXRENDERSTATE_MAP_LOD_LIMITS

The limits of the Level of Detail calculation can be controlled within GC for each Map. These values are specified in the following instruction as follows.

Figure 36. State Variable Relationships

Coordinate Sets

Map Information

Texels

Blending Stages

DWord

Bit

Description

 

 

 

0

31:29

Client : 03h – Rendering Engine

 

 

 

 

28:24

3DState16 : 1Ch

 

 

 

 

23:19

Opcode : 3h

 

 

 

 

18:17

Reserved: 00h (Additional Maps)

 

 

 

 

16

Update Map Index : The valid range is 0–1.

 

 

 

 

15:14

Reserved: 00h

 

 

 

 

13

Maximum Mip Level Mask : 0 = Do not update; 1 = Update

 

 

 

 

12:5

Maximum Mip Level : This is an unsigned 4.4 bit value which defines the highest

 

 

resolution map which may be accessed. A value of 0 equates to no limit on the mip

 

 

map selection. Values 1 through 10 will force the mip map selection to be between the

 

 

specified value and the highest defined mip map (the lowest resolution map). This

 

 

value must be less than the Minimum Mip Level.

 

 

 

 

4

Minimum Mip Level Mask : 0 = Do not update; 1 = Update

 

 

 

 

3:0

Minimum Mip Level : This is an unsigned 4 bit value which defines the lowest

 

 

resolution map which may be accessed. Values 0 through 10 will force the mip map

 

 

selection to be between the maximum resolution mip map and the specified value.

 

 

This value must be correctly identified for the current map (no assumptions are made

 

 

about the number of mips associated with a particular map). This value must also be

 

 

greater than the Maximum Mip Level.

 

 

 

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Intel 815 manual Gfxrenderstatemaplodlimits, Opcode 3h