SDK_WaterCheapFresnelOpaque_ps14.psh #1

ps.1.4

; Get the 3-vector from the normal map
texld  r0, t0
; Get environment matrix
texcrd r1.rgb, t1
texcrd r2.rgb, t2
texcrd r3.rgb, t3
; Normalize eye-ray vector through normalizer cube map
texld  r4, t4                  ; <---- CUBE MAP here!!!

; Transform normal
dp3    r5.r, r1, r0_bx2
dp3    r5.g, r2, r0_bx2
dp3    r5.b, r3, r0_bx2
; Reflection calculatiom
dp3_x2 r3.rgb, r5, r4_bx2      ; 2(N.Eye)
mul    r3.rgb, r5, r3          ; 2N(N.Eye)
dp3    r2.rgb, r5, r5          ; N.N
mad    r2.rgb, -r4_bx2, r2, r3 ; 2N(N.Eye) - Eye(N.N)

phase

; Sample environment map
texld  r3, r2
texld  r4, t5					; Normalize the tangent-space eye vector
	 
; dot eye-vector with per-pixel normal from r0
dp3_sat	r1, r4_bx2, r0_bx2

; run Fresnel approx. on it: R0 + (1-R0) (1-cos(q))^5 in alpha channel
mul r0.a, 1-r1.a, 1-r1.a			; squared
mul r0.a, r0.a, r0.a				; quartic
mul_sat r1.a, r0.a, 1-r1.a			; quintic

; multiply color by reflecttint
mul r0, r3, c1

; blend between reflected color and fog color based on fresnel
lrp r0.rgb, r1.a, r0, c0