// This file is distributed under a BSD license. See LICENSE.txt for details.

ps.2.0
// material 2.0: fat shader (pixel shader)

// flag data layout, constants
flags
	Flags
	_pad[7]
	
	TexFlags[4]
	TexScale[4]
	
	LgtFlags[4]
	LgtScale[4]
	
	SRT1[9]
	SRT2[5]
	ColC[4]
	
	TexUsed[4]
	LgtUsed[4]
	SrcScale[4]
	SrcScale2[4]
endflags

alias cDiffuse = c0
alias cSpecular = c1
def   c8,1,1,1,0
def   c9,1,0,0,4

// texture coords and samplers
alias tAtten = t0
alias tL = t1
alias tH = t2

dcl   tAtten.xyz
dcl   tL.xyz

if Flags[0] // specular 
  imov  i1,3
  dcl   tH.xyz
else
  imov  i1,2
endif

imov  i2,i1
imov  i3,0

for i=0..1 // bump maps
  if LgtUsed[i][0]
    dcl     t0+i2.xy
    dcl_2d  s0+i3
    iadd    i2,1
    iadd    i3,1
  endif
endfor

for i=0..2 // textures
	if TexUsed[i][0]
		dcl			t0+i2.xy
		dcl_2d	s0+i3
		iadd		i2,1
		iadd    i3,1
	endif
endfor

// normal
temp    N0,N

vmov    N0,c9
imov    i2,i1
imov    i3,0

for i=0..1  // bump maps
  if LgtUsed[i][0]
    temp    map
    
    // load tex
    texld   map,t0+i2,s0+i3
    
    // accumulate
    if i3 == 0
      vmov    N0,map
    else
      add     N0,N0,map
    endif
    
    // increment steps
    iadd    i2,1
    iadd    i3,1
    free    map
  endif
endfor

// renormalize normal if necessary
if i3 > 1
  nrm   N,N0
elif Flags[5] // renormalize bump
  nrm   N,N0
else
  vmov  N,N0
endif

// material 1
temp  accu

if TexUsed[0][0] // main texture?
  texld   accu,t0+i2,s0+i3
  iadd    i2,1
  iadd    i3,1
else
  mov     accu,c8 // use white
endif

// diffuse
temp    cDiff,L
nrm     L.xyz,tL
dp3_sat cDiff.r,L,N
mul     cDiff.rgb,cDiffuse,cDiff.r

// specular
temp    cSpec
if Flags[0]
  temp    H
  
  nrm     H.xyz,tH
  dp3_sat cSpec.a,H,N
  pow     cSpec.a,cSpec.a,cSpecular.a
  mul     cSpec.rgb,cSpecular,cSpec.a
endif

// detail
for i=1..2
  if TexUsed[i][0] // detail i used?
    temp    detail
    
    texld   detail,t0+i2,s0+i3
    iadd    i2,1
    iadd    i3,1
    
    if TexFlags[i][16..19] == 0 // mul
      mul     accu.rgb,accu,detail
    elif TexFlags[i][16..19] == 1 // mul2
      mul     accu.rgb,accu,detail
      add     accu.rgb,accu,accu
    elif TexFlags[i][16..19] == 2 // mul4
      mul     accu.rgb,accu,detail
      mul     accu.rgb,accu,c9.w
    elif TexFlags[i][16..19] == 3 // add
      add     accu.rgb,accu,detail
    elif TexFlags[i][16..19] == 4 // addsmooth
      temp    accu2
      lrp     accu2.rgb,detail,c8,accu
      vmov    accu,accu2
    endif
  endif
endfor

// shade
temp    color

if Flags[0]
  mad     color.rgb,accu,cDiff,cSpec
else
  mul     color.rgb,accu,cDiff
endif

// attenuation
dp3_sat   color.a,tAtten,tAtten
mad_sat   color.rgb,color,-color.a,color

// clear alpha
mov       oC0,color