User's Manual

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

229

Dword Bit Description

0 6 Invert Color Arg2:

0 = Do not Invert Argument

1 = Invert Argument

5 Color Operation Mask : 0 = Do not update; 1 = Update

4:0 Color Operation: Valid values are :

00h = The user must explicitly disable each blend stage that is not used. Note: The

user must ensure that if a blend stage is disabled, all higher number blend

stages must be disabled too. E.g. It is invalid to disable stage 2 and use only

stages 1 and 3.

(This bit disables/enables both the color and the corresponding alpha stage)

01h = Select Arg1

02h = Select Arg2

03h = Modulate

04h = Modulate and Multiply by 2

05h = Modulate and Multiply by 4

06h = Add

07h = Add Signed

08h = Linearly Blend using the Iterated Alpha as the Blend Term

09h = Reserved

0Ah = Linearly Blend using the Alpha Factor as the Blend Term

0Bh = Reserved (Linearly Blend when a pre-multiplied map alpha is present)

0Ch = Reserved (Pre-modulate)

0Ch = Reserved (Bump/Environment Map)

0Dh = Reserved (Bump pre-modulate with luminance channel)

0Fh = Reserved

10h = Linearly Blend using Texel0’s Alpha as the Blend Term

11h = Linearly Blend using Texel1’s Alpha as the Blend Term

12h = Linearly Blend using Texel0’s Color as the Blend Term

13h = Linearly Blend using Texel1’s Color as the Blend Term

14h = Subtract (Arg1 - Arg2)

15h=1Fh – Reserved