;****************************************************************************************
; PinkGas.NVP
; A shader for tinting an image pink; used in the Kewlett psych-gas grenade effect.
; Works by converting the image to greyscale, and using the brightness as a blend
; factor between two other colors. So, if the greyscale is white, it will pick
; color #1, if it is black it will pick color #2.
; TimS, Sept 7 2004
;****************************************************************************************

ps.1.1  								; Declare pixel shader version

def c1, 0.21f, 0.715f, 0.072f, 0.0f   	; luminance conversion constant

;def c3, 0.99f, 0.81f, 0.85f, 1.0f    	; Pink
;def c4, 0.15f, 0.06f, 0.10f, 1.0f    	; dark Pink

def c3, 0.97f, 0.44f, 0.98f, 1.0f    	; Bright
def c4, 0.14f, 0.0f,  0.55f, 1.0f    	; Dark


tex t0                      			; Fetch the texture we'll be tinting

dp3    r1.rgba, t0, c1          		; Convert the image to greyscale, stored in r1
lrp r0.rgb, r1, c3, c4          		; Use the greyscale as a blend factor between the colours in c3 and c4
mul r0, r0, c2                          ; Multiply in program-supplised RGBA's