shadowmodel.psh

hl2 source code. Do not use it illegal.

ps.1.1

;------------------------------------------------------------------------------
; Draw a texture . . woo hoo!
; t0 - texture
;
; The texture coordinates need to be defined as follows:
; tc0 - texcoords
;------------------------------------------------------------------------------

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

tex t0		; shadow color
texkill t1	; Clip
texkill t2
texkill t3	; backface cull

; Darkening equation, compute a color = (shadow color * shadow alpha + 1- shadow alpha)
;sub r1, t0, v0.a			; r1 = shadow alpha
lrp r0.rgb, t0.a, v0, c0 +	; r0.rgb = (shadow color * shadow alpha + 1 - shadow alpha)
mov r0.a, c0.a				; r0.a = 1