bumpmappedlightmap_lightingonly_overbright2.psh

hl2 source code. Do not use it illegal.

ps.1.1

;------------------------------------------------------------------------------
; Computes the diffuse component of lighting using lightmap + bumpmap
; t0 - Normalmap
; t1 - Lightmap1
; t2 - Lightmap2
; t3 - Lightmap3
;
; The texture coordinates need to be defined as follows:
; tc0 - Normalmap and lightmap texture coordinates
; c0, c1, c2 - Axes of the lightmap coordinate system in tangent space 
; c3 = a
; c4 = b 
; c5 = c in a quadratic approx to pow( 1/2.2 )
;------------------------------------------------------------------------------

; Get the 3-vector from the normal map
tex t0

; Sample the lightmaps
tex t1 
tex t2 
tex t3 

; Compute the dot product of axis 1 and the normal
dp3_sat r1, t0_bx2, c0

; Modulate the lightmap color by N dot Axis 1
mul r0, t1, r1

; Do the same for the other two axes
dp3_sat r1, t0_bx2, c1
mad r0, r1, t2, r0

dp3_sat r1, t0_bx2, c2
mad r0, r1, t3, r0

; Do quadratic approximation to pow( x, 1 / 2.2 )
;mad r1, c3, r0, c4		; r1 = a*x + b
;mad_x4_sat r0, r1, r0, c5		; r0 = r1*x + c = a*x*x + b*x + c