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

ps.2.0
// material 2.0: envi 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

def c0,-2,0,-0.5,0.5

// texture coords and samplers
alias tBasisX = t0
alias tEye = t1
alias tUV = t2
alias tBasisY = t3
alias tBasisZ = t4

alias sEnvi = s0
alias sBump = s1

dcl     tBasisX.xyz
dcl     tEye.xyz
dcl_2d  sEnvi

if LgtFlags[2][17]
  dcl     tUV.xy
  dcl     tBasisY.xyz
  dcl     tBasisZ.xyz
  dcl_2d  sBump
elif Flags[7]
  dcl     tUV.xy
  dcl_2d  sBump
endif

// sample bump if required
temp    normalMap
if LgtFlags[2][17] // bumped
  texld   normalMap,tUV,sBump
elif Flags[7] // specular map
  texld   normalMap,tUV,sBump
endif

// calc input normal
temp    inN

if LgtFlags[2][17] // bumped
  mul   inN.xyz,normalMap.x,tBasisX
  mad   inN.xyz,normalMap.y,tBasisY,inN
  mad   inN.xyz,normalMap.z,tBasisZ,inN
else // unbumped
  vmov  inN,tBasisX
endif

// calc reflected dir
temp    envDir

if LgtFlags[2][16] // reflection
  // R = eye - 2 * (eye . N) * N
  temp    eye
  
  nrm     eye.xyz,tEye
  nrm     envDir.xyz,inN
  dp3     eye.w,eye,envDir
  mul     envDir.xyz,envDir,eye.w
  mad     envDir.xyz,envDir,c0.x,eye
else // just normal
  vmov    envDir,inN
endif

// sample envmap
temp  color,smpUV

nrm   smpUV.xyz,envDir
mad   smpUV.xy,smpUV,c0.wzyx,c0.w
texld color,smpUV,sEnvi

// weight with specular map if desired
if Flags[7]
  mul   color.rgb,color,normalMap.a
endif

mov   oC0,color