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

ps.2.0
// material 2.0: texture pass (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]
	LgtType
endflags

alias cAmbient = c0
alias cMatrix0 = c1, cMatrix1 = c2, cMatrix2 = c3
def   c8,1,1,1,0
def   c9,4,0,0,0

// texture coords and samplers
imov i1,0

/* no paralax mapping yet
if Flags[1] // if paralax mapping is enabled, we need to sample the bump textures
	for i = 0..1
		if LgtUsed[i]
			dcl			t0+i1
			dcl_2d	s0+i1
			iadd		i1,1
		endif
	endif
endif*/

for i = 0..2 // texture samplers
	if TexUsed[i][0]
		dcl			t0+i1.xy
		dcl_2d	s0+i1
		iadd		i1,1
	endif
endfor

imov i1,0

// actual shader code
temp  accu

if TexUsed[0][0] // main texture?
  texld   accu,t0+i1,s0+i1
  iadd    i1,1
else
  mov     accu,c8 // use white
endif

if Flags[9] // main color correct
  temp    tmpcol
  mov     tmpcol.rgb, accu
  mov     tmpcol.a, c8.x
  dp4_sat accu.r, tmpcol, cMatrix0
  dp4_sat accu.g, tmpcol, cMatrix1
  dp4_sat accu.b, tmpcol, cMatrix2
endif

for i=1..2 // detail textures
  if TexUsed[i][0] // detail i used?
    temp    detail
    
    texld   detail,t0+i1,s0+i1
    iadd    i1,1
    
    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.x
    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

// ambient light level
mul   accu.rgb,accu,cAmbient
mov   oC0,accu