sgn (Vertex Shader)

Computes the sign of the input.

Syntax

sgn dst, src0, src1, src2

where

dst is the destination register.
src0 is a source register.
src1 is a source register.
src2 is a source register.

Remarks

Vertex shader versions	1_1	2_0	2_x	2_sw	3_0	3_sw
sgn		x	x	x	x	x

This instruction works as shown below.

for each component in src0
{
   if (src0.component <  0) 
       dest.component = -1; 
   else
       if (src0.component == 0) 
           dest.component = 0; 
       else 
           dest.component = 1;
}

This is a macro instruction, which takes three instruction slots.

src1, and src2 should be different temporary registers.

Instruction Information

Minimum operating system	Windows 98