Code doubt

[iris_raj]

Dear shader programmers,

I am new to shader programming

What does the (((IN.Pos.xy / IN.Pos.w) + 1) / 2 indicate.

The code snippet is
float2 texc = ((IN.Pos.xy / IN.Pos.w) + 1) / 2;

With regards
RAJESH.R

[zeoverlord]

It looks like some kind of texture projection with bias transformation.
Used for things like depth map shadows.

[tomtrenki]

This code calculates a texture coordinate on the screen.
I used this and a dudv map to create refractive materials.