User's Manual

Intel® 815 Chipset: Graphics Controller PRM, Rev 1.0
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The Zero blend factor is :
Rout = 0
Gout = 0
Bout = 0
Aout = 0
The One blend factor is :
Rout = Rin
Gout = Gin
Bout = Bin
Aout = Ain
The Src_Color blend factor is :
Rout = Rs * Rin
Gout = Gs * Gin
Bout = Bs * Bin
Aout = As * Ain
The Inv_Src_Color blend factor is :
Rout = (1 - Rs) * Rin
Gout = (1 - Gs) * Gin
Bout = (1 - Bs) * Bin
Aout = (1 - As) * Ain
The Src_Alpha blend factor is :
Rout = As * Rin
Gout = As * Gin
Bout = As * Bin
Aout = As * Ain
The Inv_Src_Alpha blend factor is :
Rout = (1 - As) * Rin
Gout =(1 - As) * Gin
Bout = (1 - As) * Bin
Aout = (1 - As) * Ain
The Dst_Color blend factor is :
Rout = Rd * Rin
Gout = Gd * Gin
Bout = Bd * Bin
Aout = Ad * Ain
The Inv_Dst_Color blend factor is :
Rout = (1 - Rd) * Rin
Gout = (1 - Gd) * Gin
Bout = (1 - Bd) * Bin
Aout = (1 - Ad) * Ain
The Both_Src_Alpha blend factor is :
Source :
Rout = As * Rin
Gout = As * Gin
Bout = As * Bin
Aout = As * Ain
Destination :
Rout = (1 - As) * Rin
Gout = (1 - As) * Gin
Bout = (1 - As) * Bin
Aout = (1 - As) * Ain
The Both_Inv_Src_Alpha blend factor
is :
Source :
Rout = (1 - As) * Rin
Gout = (1 - As) * Gin
Bout = (1 - As) * Bin
Aout = (1 - As) * Ain
Destination :
Rout = As * Rin
Gout = As * Gin
Bout = As * Bin
Aout = As * Ain
The blending factors shall be applied to the source and destination RGBA values and computed using
one of the blending equations shown below. The equation is selected by a state variable.
Add: Cs * S + Cd * D
Where Cs is the source RGBA, Cd is the destination RGBA, S is the source blending factor, and D is the
destination blending factor.