Source Register Bias
Subtract 0.5 from all components.
Source register. For more about register types, see ps_1_1__ps_1_2__ps_1_3__ps_1_4 Registers.
The contents of the register are not changed. The modifier is applied only to the data read from the register. The bias is applied to all four color channels (RGBA) as follows:
output = (input - 0.5)
The effect is to modify data that was in the range 0 to 1 to be in the range -0.5 to 0.5. Applying bias to data outside this range may produce undefined results.
Note This modifier is mutually exclusive with Source Register Invert, so it cannot be applied to the same register.
This modifier is for use with the arithmetic instructions.
This example performs the same operation as D3DTOP_ADDSIGNED in DirectX 6.0 and 7.0 multiple texture syntax.
add r0, r0, t0_bias; Shift down by 0.5.