User's Manual

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0

232

DWord Bit Description

0 4:0 Alpha Operation: Valid values are :

00h = Reserved

(Enable/Disable of stage is programmed in the Color Operation field)

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–1Fh = Reserved

13.14. GFXRENDERSTATE_COLOR_FACTOR

This instruction specifies a constant color factor, which can be used in the blending stages.

DWord Bit Description

0 31:29 Client : 03h – Rendering Engine

28:24 3DStateMW : 1Dh

23:16 Instruction : 1h

15:0 DWORD_LENGTH : 0

1 31:0 Color Factor: This is a 32 bit value in ARGB 8888 format. The top 8 bits used by the

alpha blending stage and the lower 24 bits used by the color blending stage.