shadow.psh

hl2 source code. Do not use it illegal.

ps.1.1

def c0, 1.0f, 1.0f, 1.0f, 1.0f

tex t0

; To accomplish shadow fading, subtract vertex alpha from texture alpha
; color channel isn't used...
sub_sat r0.a, t0.a, v0.a

; Blend between white and the constant color...
lrp r0.rgba, 1-r0.a, c0, c1