materials/shaders/shaderstrauss.cpp

//////////////////////////////////////////////////////////////////////////////
//
//    Strauss Shader plug-in, implementation
//
//    Created: 10/26/98 Kells Elmquist
//
#include "shadersPch.h"
#include "shadersRc.h"
#include "gport.h"
#include "shaders.h"
#include "shaderUtil.h"
#include "macrorec.h"
#include "toneop.h"

#include "3dsmaxport.h"

// Class Ids
#define STRAUSS_SHADER_CLASS_ID     0x2857f450

static Class_ID StraussShaderClassID( STRAUSS_SHADER_CLASS_ID, 0);

// paramblock2 block and parameter IDs.
enum { strauss_params, };
// shdr_params param IDs
enum
{
   st_diffuse, st_glossiness, st_metalness,
};

/////////////////////////////////////////////////////////////////////
//
// Basic Panel UI
//
#define NMBUTS 4

// tex channel number to button IDC
static int texMButtonsIDC[] = {
   IDC_MAPON_CLR, IDC_MAPON_GL, IDC_MAPON_MT, IDC_MAPON_TR,
};

// This array gives the texture map number for given MButton number
static int texmapFromMBut[] = { 0, 1, 2, 3 };

// Texture Maps
#define STRAUSS_NTEXMAPS   5

// channels ids used by shader
#define S_DI   0
#define S_GL   1
#define S_MT   2
#define S_TR   3

// channel names
static int texNameIDS[STD2_NMAX_TEXMAPS] = {
   IDS_KE_COLOR,  IDS_KE_GLOSSINESS, IDS_KE_METALNESS, IDS_DS_TRANS,
   IDS_KE_REFR_FILTER, IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE,
   IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE,
   IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE,
   IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE,
   IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE, IDS_KE_NONE,
};

// internal non-local parsable channel map names
static TCHAR* texInternalNames[STD2_NMAX_TEXMAPS] = {
   _T("diffuseMap"),_T("glossinessMap"), _T("metalnessMap"), _T("opacityMap"),
   _T("filterMap"), _T(""), _T(""), _T(""),
   _T(""), _T(""), _T(""), _T(""),
   _T(""), _T(""), _T(""), _T(""),
   _T(""), _T(""), _T(""), _T(""),
   _T(""), _T(""), _T(""), _T(""),
};

// sized for nmax textures
// bump, reflection & refraction maps are ignored....done after shading
static int chanType[STD2_NMAX_TEXMAPS] = {
   CLR_CHANNEL, MONO_CHANNEL, MONO_CHANNEL, MONO_CHANNEL,
   CLR_CHANNEL, UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL,
   UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL,
   UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL,
   UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL,
   UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL, UNSUPPORTED_CHANNEL,
};

// what channel corresponds to the stdMat ID's
static int stdIDToChannel[N_ID_CHANNELS] = { -1, 0, -1, 1, -1, -1, 3, 4, -1, -1, -1, -1, -1, -1, -1, -1 };


//////////////////////////////////////////////////////////////////////////////////////////
//
//    Strauss Parameter Block
//
#define CURRENT_STRAUSS_SHADER_VERSION 2
#define STRAUSS_SHADER_NPARAMS         4
#define STRAUSS_SHADER_PB_VERSION      1

#define STRAUSS_NCOLBOX 1
static int colID[STRAUSS_NCOLBOX] = { IDC_STD_COLOR2  };

//Current Param Block Descriptor
static ParamBlockDescID StraussShaderPB[ STRAUSS_SHADER_NPARAMS ] = {
   { TYPE_RGBA,  NULL, TRUE,st_diffuse },   // diffuse
   { TYPE_FLOAT, NULL, TRUE,-1 },  // ambient level
   { TYPE_FLOAT, NULL, TRUE,st_glossiness },   // glossiness
   { TYPE_FLOAT, NULL, TRUE,st_metalness },  // metalness
};

#define STRAUSS_NUMOLDVER 1

static ParamVersionDesc oldVersions[STRAUSS_NUMOLDVER] = {
   ParamVersionDesc(StraussShaderPB, STRAUSS_SHADER_NPARAMS, 0),
};


//----------------------------------------------------------------------------------------
// Straus Shader, from CGA Nov 1990, "Realistic lighting model for computer animators"
//----------------------------------------------------------------------------------------
// note: We replace std opacity & std reflection, these are automatic in the strauss model
#define STRAUSS_PARAMS (STD_PARAM_DIFFUSE_CLR+STD_PARAM_GLOSSINESS\
                  +STD_PARAM_SPECULAR_LEV+STD_EXTRA_DLG+STD_EXTRA_REFRACTION)

class StraussShaderDlg;

class StraussShader : public ExposureMaterialControlImp<StraussShader,
                        AddExposureMaterialControl<Shader> > {
friend class StraussShaderCB;
friend class StraussShaderDlg;
friend class ExposureMaterialControlImp<StraussShader,
   AddExposureMaterialControl<Shader> >;
   BOOL rolloutOpen;
protected:
   IParamBlock2      *pblock;   // ref 0
   Interval    ivalid;

   StraussShaderDlg* paramDlg;

   Color       diffuse;
   float       glossiness;
   float       metalness;

   static CombineComponentsFPDesc msExpMtlControlDesc;

   public:
   StraussShader();
   void DeleteThis(){ delete this; }
    ULONG SupportStdParams(){ return STRAUSS_PARAMS; }

   // copy std params, for switching shaders
    void CopyStdParams( Shader* pFrom );

   // texture maps
   long nTexChannelsSupported(){ return STRAUSS_NTEXMAPS; }
   TSTR GetTexChannelName( long nChan ){ return GetString( texNameIDS[ nChan ] ); }
   TSTR GetTexChannelInternalName( long nChan ) { return texInternalNames[ nChan ]; }
   long ChannelType( long nChan ) { return chanType[nChan]; }
   long StdIDToChannel( long stdID ){ return stdIDToChannel[stdID]; }

   BOOL KeyAtTime(int id,TimeValue t) { return pblock->KeyFrameAtTime(id,t); }
   ULONG GetRequirements( int subMtlNum ){ return isNoExposure() | MTLREQ_PHONG; }

   ShaderParamDlg* CreateParamDialog(HWND hOldRollup, HWND hwMtlEdit, IMtlParams *imp, StdMat2* theMtl, int rollupOpen, int );
   ShaderParamDlg* GetParamDlg(int){ return (ShaderParamDlg*)paramDlg; }
   void SetParamDlg( ShaderParamDlg* newDlg, int ){ paramDlg = (StraussShaderDlg*)newDlg; }

   Class_ID ClassID() { return StraussShaderClassID; }
   SClass_ID SuperClassID() { return SHADER_CLASS_ID; }
   TSTR GetName() { return GetString( IDS_KE_STRAUSS ); }
   void GetClassName(TSTR& s) { s = GetName(); }

   int NumSubs() { return 1; }
   Animatable* SubAnim(int i){ return (i==0)? pblock : NULL; }
   TSTR SubAnimName(int i){ return TSTR(GetString( IDS_KE_STRAUSS_PARMS )); };
   int SubNumToRefNum(int subNum) { return subNum; }

   // add direct ParamBlock2 access
   int   NumParamBlocks() { return 1; }
   IParamBlock2* GetParamBlock(int i) { return pblock; }
   IParamBlock2* GetParamBlockByID(BlockID id) { return (pblock->ID() == id) ? pblock : NULL; }

   int NumRefs() { return 1; }
   RefTargetHandle GetReference(int i){ return (i==0)? pblock : NULL; }
   void SetReference(int i, RefTargetHandle rtarg)
      { if (i==0) pblock = (IParamBlock2*)rtarg; else assert(0); }
   void NotifyChanged(){ NotifyDependents(FOREVER, PART_ALL, REFMSG_CHANGE); }

   void Update(TimeValue t, Interval& valid);
   void Reset();
   RefTargetHandle Clone( RemapDir &remap=DefaultRemapDir() );
   RefResult NotifyRefChanged( Interval changeInt, RefTargetHandle hTarget,
                               PartID& partID, RefMessage message );
   // IO
   IOResult Save(ISave *isave);
   IOResult Load(ILoad *iload);

   void GetIllumParams( ShadeContext &sc, IllumParams& ip );

   // Strauss Shader specific section
   void  Illum(ShadeContext &sc, IllumParams &ip);
   float EvalHiliteCurve(float x);

   void AffectReflection(ShadeContext &sc, IllumParams &ip, Color &rcol);
   void CombineComponents( ShadeContext &sc, IllumParams& ip );

   void SetGlossiness(float v, TimeValue t){ glossiness= v; pblock->SetValue( st_glossiness, t, v); }
   float GetGlossiness(int mtlNum=0, BOOL backFace=FALSE){ return glossiness; };
   float GetGlossiness( TimeValue t){return pblock->GetFloat(st_glossiness,t);  }

   void SetMetalness(float v, TimeValue t){ metalness = v; pblock->SetValue( st_metalness, t, v); }
   float GetMetalness(int mtlNum=0, BOOL backFace=FALSE){ return metalness; };
   float GetMetalness( TimeValue t){return pblock->GetFloat(st_metalness,t);  }

   // Std Params
   void SetDiffuseClr(Color c, TimeValue t)
      { diffuse = c; pblock->SetValue( st_diffuse, t, c); }

    Color GetDiffuseClr(int mtlNum=0, BOOL backFace=FALSE){ return diffuse;}
   Color GetDiffuseClr(TimeValue t){ return pblock->GetColor(st_diffuse,t); }

   // std params not supported
   void SetLockDS(BOOL lock){ }
   BOOL GetLockDS(){ return FALSE; }
   void SetLockAD(BOOL lock){ }
   BOOL GetLockAD(){ return FALSE; }
   void SetLockADTex(BOOL lock){ }
   BOOL GetLockADTex(){ return FALSE; }
   void SetAmbientClr(Color c, TimeValue t){}
   Color GetAmbientClr(int mtlNum=0, BOOL backFace=FALSE){ return diffuse * 0.5f;}
   Color GetAmbientClr(TimeValue t){ return diffuse * 0.5f; }

   void SetSpecularClr(Color c, TimeValue t){}
   void SetSpecularLevel(float v, TimeValue t){}
   Color GetSpecularClr(int mtlNum=0, BOOL backFace=FALSE){ return Color(0.9f, 0.9f,0.9f); };
   float GetSpecularLevel(TimeValue t);
   float GetSpecularLevel(int mtlNum, BOOL backFace){ return GetSpecularLevel(0); };
   Color GetSpecularClr(TimeValue t){ return Color(0.9f,0.9f,0.9f);}
   void SetSelfIllum(float v, TimeValue t)   {}
   float GetSelfIllum(int mtlNum=0, BOOL backFace=FALSE){ return 0.0f; };
   void SetSelfIllumClrOn( BOOL on ){};
   BOOL IsSelfIllumClrOn(){ return TRUE; };
   BOOL IsSelfIllumClrOn(int mtlNum, BOOL backFace){ return TRUE; }
   void SetSelfIllumClr(Color c, TimeValue t){}
   Color GetSelfIllumClr(int mtlNum=0, BOOL backFace=FALSE){ return Color(0,0,0); }
   void SetSoftenLevel(float v, TimeValue t) {}
   float GetSoftenLevel(int mtlNum=0, BOOL backFace=FALSE){ return DEFAULT_SOFTEN; }
   float GetSoftenLevel(TimeValue t){ return  DEFAULT_SOFTEN; }
   float GetSelfIllum(TimeValue t){ return 0.0f;}
   Color GetSelfIllumClr(TimeValue t){ return Color(0,0,0);}

   void SetPanelOpen(BOOL open){rolloutOpen = open;}


};

///////////// Class Descriptor ////////////////////////
class StraussShaderClassDesc:public ClassDesc2 {
   public:
   int         IsPublic() { return 1; }
   void *         Create(BOOL loading) {  return new StraussShader(); }
   const TCHAR *  ClassName() { return GetString(IDS_KE_STRAUSS); }
   SClass_ID      SuperClassID() { return SHADER_CLASS_ID; }
   Class_ID       ClassID() { return StraussShaderClassID; }
   const TCHAR*   Category() { return _T("");  }
   const TCHAR*   InternalName() { return _T("Strauss"); } // returns fixed parsable name (scripter-visible name)
   HINSTANCE      HInstance() { return hInstance; }          // returns owning module handle
};

StraussShaderClassDesc StraussCD;
ClassDesc * GetStraussShaderCD(){ return &StraussCD; }

// shader parameters
static ParamBlockDesc2 strauss_param_blk ( strauss_params, _T("shaderParameters"),  0, &StraussCD, P_AUTO_CONSTRUCT, 0,
   // params
   st_diffuse, _T("diffuse"), TYPE_RGBA, P_ANIMATABLE, IDS_DS_DIFFUSE,
      p_default, Color(0.5f, 0.5f, 0.5f),
      end,
   st_glossiness, _T("glossiness"), TYPE_PCNT_FRAC, P_ANIMATABLE, IDS_KE_GLOSSINESS,
      p_default,     0.0,
      p_range,    0.0, 100.0,
      end,
   st_metalness, _T("metalness"), TYPE_PCNT_FRAC, P_ANIMATABLE, IDS_KE_METALNESS,
      p_default,     0.0,
      p_range,    0.0, 100.0,
      end,
   end
);


CombineComponentsFPDesc StraussShader::msExpMtlControlDesc(StraussCD);

StraussShader::StraussShader()
{
   pblock = NULL;
   StraussCD.MakeAutoParamBlocks(this);   // make and intialize paramblock2
   paramDlg = NULL;
   diffuse = Color(0.0f,0.0f,0.0f);
   glossiness = metalness = 0.0f;
   ivalid.SetEmpty();
   rolloutOpen = TRUE;

}

void StraussShader::CopyStdParams( Shader* pFrom )
{
   macroRecorder->Disable();
   // don't want to see this parameter copying in macrorecorder

      SetAmbientClr( pFrom->GetAmbientClr(0,0), 0 );
      SetDiffuseClr( pFrom->GetDiffuseClr(0,0), 0 );
      SetGlossiness( pFrom->GetGlossiness(0,0), 0 );

   macroRecorder->Enable();
   ivalid.SetEmpty();
}


RefTargetHandle StraussShader::Clone( RemapDir &remap )
{
   StraussShader* mnew = new StraussShader();
   mnew->ExposureMaterialControl::operator=(*this);
   mnew->ReplaceReference(0, remap.CloneRef(pblock));
   mnew->ivalid.SetEmpty();
   mnew->diffuse = diffuse;
   mnew->glossiness = glossiness;
   mnew->metalness = metalness;
   BaseClone(this, mnew, remap);
   return (RefTargetHandle)mnew;
}

void StraussShader::GetIllumParams( ShadeContext &sc, IllumParams& ip )
{
   ip.stdParams = SupportStdParams();
   ip.channels[S_DI] = diffuse;
   ip.channels[S_GL].r = glossiness;
   ip.channels[S_MT].r = metalness;
}


void StraussShader::Update(TimeValue t, Interval &valid) {
   Point3 p;
   if (!ivalid.InInterval(t)) {
      ivalid.SetInfinite();

      pblock->GetValue( st_diffuse, t, p, ivalid );
      diffuse= Bound(Color(p.x,p.y,p.z));
      pblock->GetValue( st_glossiness, t, glossiness, ivalid );
      glossiness = Bound(glossiness );
      pblock->GetValue( st_metalness, t, metalness, ivalid );
      metalness = Bound(metalness );
   }
   valid &= ivalid;
}

void StraussShader::Reset()
{
// StraussCD.MakeAutoParamBlocks(this);   // make and intialize paramblock2

   ivalid.SetEmpty();
   SetDiffuseClr( Color(0.5f,0.5f,0.5f), 0 );
   SetGlossiness( 0.2f,0);
   SetMetalness( 0.0f,0);
}


//////////////////////////////////////////////////////////////////////////////////////////
//
// IO Routines
//
#define SHADER_HDR_CHUNK 0x4000
#define SHADER_MAPSON_CHUNK 0x5004
#define SHADER_VERS_CHUNK 0x5300
#define SHADER_DIMDIFFON_CHUNK 0x5400
#define SHADER_EXPOSURE_MATERIAL_CONTROL_CHUNK  0x5020

// IO
IOResult StraussShader::Save(ISave *isave)
{
ULONG nb;

   isave->BeginChunk(SHADER_VERS_CHUNK);
   int version = CURRENT_STRAUSS_SHADER_VERSION;
   isave->Write(&version,sizeof(version),&nb);
   isave->EndChunk();

   isave->BeginChunk(SHADER_EXPOSURE_MATERIAL_CONTROL_CHUNK);
   ExposureMaterialControl::Save(isave);
   isave->EndChunk();
   return IO_OK;
}

class StraussShaderCB: public PostLoadCallback {
   public:
      StraussShader *s;
      int loadVersion;
       StraussShaderCB(StraussShader *newS, int loadVers) { s = newS; loadVersion = loadVers; }
      void proc(ILoad *iload)
      {
         s->ReplaceReference(0,
            UpdateParameterBlock2(StraussShaderPB, STRAUSS_SHADER_NPARAMS, (IParamBlock*)s->pblock, &strauss_param_blk));
      }
};


IOResult StraussShader::Load(ILoad *iload) {
   ULONG nb;
   int id;
   int version = 0;

   IOResult res;
   while (IO_OK==(res=iload->OpenChunk())) {
      switch(id = iload->CurChunkID())  {
         case SHADER_VERS_CHUNK:
            res = iload->Read(&version,sizeof(version), &nb);
            break;
         case SHADER_DIMDIFFON_CHUNK:
            BOOL dim;
            res = iload->Read(&dim,sizeof(dim), &nb);
            break;
         case SHADER_EXPOSURE_MATERIAL_CONTROL_CHUNK:
            res = ExposureMaterialControl::Load(iload);
            break;
      }
      iload->CloseChunk();
      if (res!=IO_OK)
         return res;
   }
   if (version < CURRENT_STRAUSS_SHADER_VERSION ) {
      iload->RegisterPostLoadCallback(new StraussShaderCB(this, version));
      iload->SetObsolete();
   }
   return IO_OK;
}


///////////////////////////////////////////////////////////////////////////////////////////
// The Shader
//

// my magic constants
static float SpecBoost = 1.3f;

// Strauss's Magic Constants
static float kf = 1.12f;
static float kf2 = 1.0f / (kf * kf);
static float kf3 = 1.0f / ((1.0f - kf) * (1.0f - kf));
static float kg = 1.01f;
static float kg2 = 1.0f / (kg * kg);
static float kg3 = 1.0f / ((1.0f - kg) * (1.0f - kg));
static float kj = 0.1f; //.1 strauss

static float OneOverHalfPi = 1.0f / (0.5f * Pi);

inline float F( float x ){
   float xb = Bound( x );
   float xkf = 1.0f / ((xb - kf)*(xb - kf));
   return (xkf - kf2) / (kf3 - kf2);
}

inline float G( float x ){
   float xb = Bound( x );
   float xkg = 1.0f / ((xb - kg)*(xb - kg));
   return (kg3 - xkg) / (kg3 - kg2);
}

#define REFL_BRIGHTNESS_ADJUST   3.0f;

void StraussShader::AffectReflection(ShadeContext &sc, IllumParams &ip, Color &rClr )
{
   float opac = ip.channels[ S_TR ].r;
   float g = ip.channels[ S_GL ].r;
   float m = ip.channels[ S_MT ].r;
   Color Cd = ip.channels[ S_DI ];

   float rn = opac - (1.0f - g * g * g) * opac;

   // the reflection of the reflection vector is just the view vector
   // so dot(v, r) is 1, to any power is still 1
   float a, b;
// NB: this has been transformed for existing in-pointing v
   float NV = Dot( sc.V(), sc.Normal() );
   Point3 R = sc.V() - 2.0f * NV * sc.Normal();
   float NR = Dot( sc.Normal(), R );
      a = (float)acos( NR ) * OneOverHalfPi;
      b = (float)acos( NV ) * OneOverHalfPi;

   float fa = F( a );
   float j = fa * G( a ) * G( b );
   float rj = Bound( rn + (rn+kj)*j );
   Color white( 1.0f, 1.0f, 1.0f );

   Color Cs = white + m * (1.0f - fa) * (Cd - white);
   rClr *= Cs * rj * REFL_BRIGHTNESS_ADJUST;
}

static int stopX = -1;
static int stopY = -1;

static float   greyVal = 0.3f;
static float   clrVal = 0.3f;

static float   softThresh = 0.15f;

void StraussShader::Illum(ShadeContext &sc, IllumParams &ip)
{
   LightDesc *l;
   Color lightClr;

#ifdef _DEBUG
   IPoint2 sp = sc.ScreenCoord();
   if ( sp.x == stopX && sp.y == stopY )
      sp.x = stopX;
#endif

   float opac = ip.channels[ S_TR ].r;
   float g = ip.channels[ S_GL ].r;
   float m = ip.channels[ S_MT ].r;
   Color Cd = ip.channels[ S_DI ];
// BOOL dimDiffuse = ip.hasComponents & HAS_REFLECT;
   BOOL dimDiffuse = ip.hasComponents & HAS_REFLECT_MAP;

   float rd;
   float g3 = Cube( g );
   if ( dimDiffuse )
      rd = (1.0f - g3) * opac;
   else
      rd = (1.0f - m * g3) * opac;  //ke 10/28/98

   float rn = opac - (1.0f - g3) * opac;

   float h = (g == 1.0f ) ? 600.0f : 3.0f / (1.0f - g );
   float d = 1.0f - m * g;

   for (int i=0; i<sc.nLights; i++) {
      l = sc.Light(i);
      float NL, Kl;
      Point3 L;
      if (l->Illuminate( sc, sc.Normal(), lightClr, L, NL, Kl)) {
         if (l->ambientOnly) {
            ip.ambIllumOut += lightClr;
            continue;
         }
         if (NL<=0.0f)
            continue;

         // diffuse
         if (l->affectDiffuse){
            ip.diffIllumOut += Kl * d * rd * lightClr;
         }

         // specular
         if (l->affectSpecular) {
            // strauss uses the reflected LIGHT vector
            Point3 R = L - 2.0f * NL * sc.Normal();
            R = Normalize( R );

            float RV = -Dot(R, sc.V() );

            float s;
            if (RV < 0.0f) {
               // soften
               if ( NL < softThresh )
                  RV *= SoftSpline2( NL / softThresh );
               // specular function
               s = SpecBoost * (float)pow( -RV, h);
            } else
               continue;

            float a, b;
            a = (float)acos( NL ) * OneOverHalfPi;
            b = (float)acos( -Dot(sc.Normal(), sc.V()) ) * OneOverHalfPi;

            float fa = F( a );
            float j = fa * G( a ) * G( b );
            float rj = rn > 0.0f ? Bound( rn + (rn+kj)*j ) : rn;
            Color Cl = lightClr;
            // normalize the light color in case it's really bright
            float I = NormClr( Cl );
            Color Cs = Cl + m * (1.0f - fa) * (Cd - Cl);

            ip.specIllumOut += s * rj * I * Cs;

         } // end, if specular
      }  // end, illuminate

   } // for each light

   // now we can multiply by the clrs, except specular, which is already done
   ip.ambIllumOut *= 0.5f * rd * Cd;
   ip.diffIllumIntens = Intens(ip.diffIllumOut);
   ip.diffIllumOut *= Cd;

   // next due reflection
   if ( ip.hasComponents & HAS_REFLECT ){
      Color rc = ip.channels[ ip.stdIDToChannel[ ID_RL ] ];
      AffectReflection(sc, ip, rc);
      ip.reflIllumOut = rc * ip.reflectAmt;
   }

   // last do refraction/ opacity
   if ( (ip.hasComponents & HAS_REFRACT) ){
      // Set up attenuation opacity for Refraction map. dim diffuse & spec by this
      ip.finalAttenuation = ip.finalOpac * (1.0f - ip.refractAmt);

      // Make more opaque where specular hilite occurs:
      float max = Max(ip.specIllumOut);
      if (max > 1.0f) max = 1.0f;
         float newOpac = ip.finalAttenuation + max - ip.finalAttenuation * max;

      // Evaluate refraction map, filtered by filter color.
//    Color tClr = ((StdMat2*)(ip.pMtl))->TranspColor( newOpac, ip.channels[filtChan], ip.channels[diffChan]);
      Color tClr = transpColor( TRANSP_FILTER, newOpac, Cd, Cd );
      ip.transIllumOut = ip.channels[ ip.stdIDToChannel[ ID_RR ] ] * tClr;

      // no transparency when doing refraction
      ip.finalT.Black();

   } else {
      // no refraction, transparent?
      ip.finalAttenuation = opac;
      if (ip.hasComponents & HAS_OPACITY) {
         // ip.finalT = Cd * (1.0f-opac);
         Cd = greyVal * Color( 1.0f, 1.0f, 1.0f ) + clrVal * Cd;
         ip.finalT = transpColor( TRANSP_FILTER, opac, Cd, Cd );
      }
   }

   if (sc.globContext != NULL && sc.globContext->pToneOp != NULL) {
      if (isInvertSelfIllum())
         sc.globContext->pToneOp->RGBToScaled(ip.selfIllumOut);
      if (isInvertReflect() && (ip.hasComponents & HAS_REFLECT))
         sc.globContext->pToneOp->RGBToScaled(ip.reflIllumOut);
      if (isInvertRefract() && (ip.hasComponents & HAS_REFRACT))
         sc.globContext->pToneOp->RGBToScaled(ip.transIllumOut);
   }

   CombineComponents( sc, ip );
}

float StraussShader::GetSpecularLevel(TimeValue t)
{
   float g3 = Cube( glossiness );

// float j = F( 0.0f ) * G( 0.0f ) * G( 0.0f );
// float j = G( 0.0f ) * G( 0.0f );
// float rj = Bound( g3 + (g3+kj)*j );
// return rj;
   return g3;
}

void StraussShader::CombineComponents( ShadeContext &sc, IllumParams& ip )
{
   float o = (ip.hasComponents & HAS_REFRACT) ? ip.finalAttenuation : 1.0f;

   ip.finalC = o * (ip.ambIllumOut + ip.diffIllumOut) + ip.specIllumOut
            + ip.reflIllumOut + ip.transIllumOut;
}

///////////////////////////////////////////////////////////////////////////////////
//
// Strauss shader dlg panel
//
class StraussShaderDlg : public ShaderParamDlg {
public:
   StraussShader* pShader;
   StdMat2* pMtl;
   HPALETTE hOldPal;
   HWND     hwmEdit; // window handle of the materials editor dialog
   IMtlParams* pMtlPar;
   HWND     hwHilite;   // the hilite window
   HWND     hRollup; // Rollup panel
   TimeValue   curTime;
   BOOL     valid;
   BOOL     isActive;

   IColorSwatch *cs[STRAUSS_NCOLBOX];
   ISpinnerControl *glSpin, *mtSpin, *trSpin;
   ICustButton* texMBut[NMBUTS];
   TexDADMgr dadMgr;

   StraussShaderDlg( HWND hwMtlEdit, IMtlParams *pParams );
   ~StraussShaderDlg();

   // required for correctly operating map buttons
   int FindSubTexFromHWND(HWND hw) {
      for (long i=0; i<NMBUTS; i++) {
         if (hw == texMBut[i]->GetHwnd())
            return texmapFromMBut[i];
      }
      return -1;
   }

   // Methods
   INT_PTR PanelProc(HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam );
   Class_ID ClassID(){ return StraussShaderClassID; }

   void SetThing(ReferenceTarget *m){ pMtl = (StdMat2*)m; }
   void SetThings( StdMat2* theMtl, Shader* theShader )
   {  if (pShader) pShader->SetParamDlg(NULL,0);
      pShader = (StraussShader*)theShader;
      if (pShader)pShader->SetParamDlg(this,0);
      pMtl = theMtl;
   }
   ReferenceTarget* GetThing(){ return pMtl; } // mtl is the thing! (for DAD!)
   Shader* GetShader(){ return pShader; }

   void SetTime(TimeValue t) {
      //DS 2/26/99: added interval test to prevent redrawing when not necessary
      curTime = t;
      if (!pShader->ivalid.InInterval(t)) {
         Interval v;
         pShader->Update(t,v);
         LoadDialog(TRUE);
      }
   }
   BOOL KeyAtCurTime(int id) { return pShader->KeyAtTime(id,curTime); }
   void DeleteThis() { delete this; }
   void ActivateDlg( BOOL dlgOn ){ isActive = dlgOn; }
   HWND GetHWnd(){ return hRollup; }
   void NotifyChanged(){ pShader->NotifyChanged(); }
   void LoadDialog(BOOL draw);
   void ReloadDialog(){ Interval v; pShader->Update(pMtlPar->GetTime(), v); LoadDialog(FALSE);}
   void UpdateDialog( ParamID paramId ){ ReloadDialog(); }

   void UpdateMtlDisplay(){ pMtlPar->MtlChanged(); } // redraw viewports
    void UpdateHilite( );
   void UpdateColSwatches();
   void UpdateMapButtons();
   void UpdateOpacity();

   void SelectEditColor(int i) { cs[ i ]->EditThis(FALSE); }
};

static INT_PTR CALLBACK  StraussShaderDlgProc(HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam) {
   StraussShaderDlg *theDlg;
   if (msg == WM_INITDIALOG) {
      theDlg = (StraussShaderDlg*)lParam;
      DLSetWindowLongPtr(hwndDlg, lParam);
   } else {
       if ( (theDlg = DLGetWindowLongPtr<StraussShaderDlg *>(hwndDlg) ) == NULL )
         return FALSE;
   }
   theDlg->isActive = 1;
   BOOL res = theDlg->PanelProc(hwndDlg, msg, wParam, lParam);
   theDlg->isActive = 0;
   return res;
}


ShaderParamDlg* StraussShader::CreateParamDialog(HWND hOldRollup, HWND hwMtlEdit, IMtlParams *imp, StdMat2* theMtl, int rollupOpen, int )
{
   Interval v;
   Update(imp->GetTime(),v);
   int rollupflags = rolloutOpen ? 0  : APPENDROLL_CLOSED;

   StraussShaderDlg *pDlg = new StraussShaderDlg(hwMtlEdit, imp);
   pDlg->SetThings( theMtl, this  );

   LoadStdShaderResources();
   if ( hOldRollup ) {
      pDlg->hRollup = imp->ReplaceRollupPage(
         hOldRollup,
         hInstance,
         MAKEINTRESOURCE(IDD_DMTL_BASIC_STRAUSS3),
         StraussShaderDlgProc,
         GetString(IDS_KE_STRAUSS_BASIC), // your name here
         (LPARAM)pDlg ,
         // NS: Bugfix 263414 keep the old category and store it for the current rollup
         rollupflags|ROLLUP_SAVECAT|ROLLUP_USEREPLACEDCAT
         );
   } else
      pDlg->hRollup = imp->AddRollupPage(
         hInstance,
         MAKEINTRESOURCE(IDD_DMTL_BASIC_STRAUSS3),
         StraussShaderDlgProc,
         GetString(IDS_KE_STRAUSS_BASIC),
         (LPARAM)pDlg ,
         rollupflags
         );

   return (ShaderParamDlg*)pDlg;
}

RefResult StraussShader::NotifyRefChanged(Interval changeInt, RefTargetHandle hTarget,
                             PartID& partID, RefMessage message )
{
   switch (message) {
      case REFMSG_CHANGE:
         ivalid.SetEmpty();
         if (hTarget == pblock){
            // update UI if paramblock changed, possibly from scripter
            ParamID changingParam = pblock->LastNotifyParamID();
            // reload the dialog if present
            if (paramDlg){
               paramDlg->UpdateDialog( changingParam );
            }
         }
         break;
   }
   return(REF_SUCCEED);
}


float StraussShader::EvalHiliteCurve( float x )
{
   float op = ( paramDlg )? paramDlg->pMtl->GetOpacity(0) : 1.0f;
   float rn = op - (1.0f - glossiness * glossiness * glossiness) * op;

   float h = (glossiness == 1.0f)? 600.0f : 3.0f / (1.0f - glossiness );
   float s = (float)pow( cos(x*PI), h);

   float a = 0.5f;
   float b = x;

   float fa = F( a );
   float j = fa * G( a ) * G( b );
   float rj = Min( 1.0f, rn + (rn+kj)*j );
   float IllumOut = SpecBoost * s * rj;

   return IllumOut;
}


StraussShaderDlg::StraussShaderDlg( HWND hwMtlEdit, IMtlParams *pParams)
{
   pMtl = NULL;
   pShader = NULL;
   hwmEdit = hwMtlEdit;
   pMtlPar = pParams;
   dadMgr.Init(this);
   glSpin = mtSpin = trSpin = NULL;
   hRollup = hwHilite = NULL;
   curTime = pMtlPar->GetTime();
   isActive = valid = FALSE;

   for( long i = 0; i < STRAUSS_NCOLBOX; ++i )
      cs[ i ] = NULL;

   for( long i = 0; i < NMBUTS; ++i )
      texMBut[ i ] = NULL;
}

StraussShaderDlg::~StraussShaderDlg()
{
   HDC hdc = GetDC(hRollup);
   GetGPort()->RestorePalette(hdc, hOldPal);
   ReleaseDC(hRollup, hdc);

   if( pShader ) pShader->SetParamDlg(NULL,0);

   for (long i=0; i < NMBUTS; i++ ){
      ReleaseICustButton( texMBut[i] );
      texMBut[i] = NULL;
   }

   for (long i=0; i<STRAUSS_NCOLBOX; i++)
      if (cs[i]) ReleaseIColorSwatch(cs[i]); // mjm - 5.10.99

   ReleaseISpinner(glSpin);
   ReleaseISpinner(mtSpin);
   ReleaseISpinner(trSpin);

   DLSetWindowLongPtr(hRollup, NULL);
   DLSetWindowLongPtr(hwHilite, NULL);

   if(pShader){
      IRollupWindow* pRollup = pMtlPar->GetMtlEditorRollup();
      pShader->SetPanelOpen(pRollup->IsPanelOpen(pRollup->GetPanelIndex(hRollup)));
   }

   hwHilite = hRollup = NULL;
}


void  StraussShaderDlg::LoadDialog(BOOL draw)
{
   if (pShader && hRollup) {
      glSpin->SetValue( FracToPc( pShader->GetGlossiness() ),FALSE);
      glSpin->SetKeyBrackets(KeyAtCurTime(st_glossiness));

      mtSpin->SetValue( FracToPc( pShader->GetMetalness() ), FALSE);
      mtSpin->SetKeyBrackets(KeyAtCurTime(st_metalness));

      trSpin->SetValue(FracToPc(pMtl->GetOpacity(curTime)),FALSE);
      trSpin->SetKeyBrackets(pMtl->KeyAtTime(OPACITY_PARAM, curTime));

      UpdateColSwatches();
      UpdateHilite();
   }
}


static TCHAR* mapStates[] = { _T(" "), _T("m"),  _T("M") };

void StraussShaderDlg::UpdateMapButtons()
{

   for ( long i = 0; i < NMBUTS; ++i ) {
      int nMap = texmapFromMBut[ i ];
      int state = pMtl->GetMapState( nMap );
      texMBut[i]->SetText( mapStates[ state ] );

      TSTR nm = pMtl->GetMapName( nMap );
      texMBut[i]->SetTooltip(TRUE,nm);
   }
}


void StraussShaderDlg::UpdateOpacity()
{
   trSpin->SetValue(FracToPc(pMtl->GetOpacity(curTime)),FALSE);
   trSpin->SetKeyBrackets(pMtl->KeyAtTime(OPACITY_PARAM, curTime));
   UpdateHilite();
}

void StraussShaderDlg::UpdateColSwatches()
{
   cs[0]->SetKeyBrackets( pShader->KeyAtTime(st_diffuse,curTime) );
   cs[0]->SetColor( pShader->GetDiffuseClr() );
}


void StraussShaderDlg::UpdateHilite()
{
   HDC hdc = GetDC(hwHilite);
   Rect r;
   GetClientRect(hwHilite,&r);
   DrawHilite(hdc, r, pShader );
   ReleaseDC(hwHilite,hdc);
}


static int ColorIDCToIndex(int idc) {
   switch (idc) {
      case IDC_COLOR: return 0;
      default: return 0;
   }
}


INT_PTR StraussShaderDlg::PanelProc(HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam )
{
   int id = LOWORD(wParam);
   int code = HIWORD(wParam);
    switch (msg) {
      case WM_INITDIALOG:
         {
         HDC theHDC = GetDC(hwndDlg);
         hOldPal = GetGPort()->PlugPalette(theHDC);
         ReleaseDC(hwndDlg,theHDC);

         HWND hwndCS = GetDlgItem(hwndDlg, IDC_COLOR);
         cs[0] = GetIColorSwatch( hwndCS, pShader->GetDiffuseClr(), GetString(IDS_KE_COLOR) );

         hwHilite = GetDlgItem(hwndDlg, IDC_HIGHLIGHT);
         DLSetWindowLongPtr( hwHilite, HiliteWndProc);

         glSpin = SetupIntSpinner(hwndDlg, IDC_GL_SPIN, IDC_GL_EDIT, 0,100, 0);
         mtSpin = SetupIntSpinner(hwndDlg, IDC_MT_SPIN, IDC_MT_EDIT, 0,100, 0);
         trSpin = SetupIntSpinner(hwndDlg, IDC_TR_SPIN, IDC_TR_EDIT, 0,100, 0);

         for (int j=0; j<NMBUTS; j++) {
            texMBut[j] = GetICustButton(GetDlgItem(hwndDlg,texMButtonsIDC[j]));
            assert( texMBut[j] );
            texMBut[j]->SetRightClickNotify(TRUE);
            texMBut[j]->SetDADMgr(&dadMgr);
         }
         LoadDialog(TRUE);
      }
      break;

      case WM_COMMAND:
         {
         for ( int i=0; i<NMBUTS; i++) {
            if (id == texMButtonsIDC[i]) {
               PostMessage(hwmEdit,WM_TEXMAP_BUTTON, texmapFromMBut[i],(LPARAM)pMtl );
               UpdateMapButtons();
               goto exit;
               }
            }
         }

         break; // WM_COMMAND

      case CC_COLOR_SEL: {
         int id = LOWORD(wParam);
         SelectEditColor(ColorIDCToIndex(id));
      }
      break;
      case CC_COLOR_DROP:  {
         int id = LOWORD(wParam);
         SelectEditColor(ColorIDCToIndex(id));
         UpdateMtlDisplay();
      }
      break;
      case CC_COLOR_BUTTONDOWN:
         theHold.Begin();
       break;
      case CC_COLOR_BUTTONUP:
         if (HIWORD(wParam)) theHold.Accept(GetString(IDS_DS_PARAMCHG));
         else theHold.Cancel();
         UpdateMtlDisplay();
         break;
      case CC_COLOR_CHANGE: {
         int id = LOWORD(wParam);
         int buttonUp = HIWORD(wParam);
         int n = ColorIDCToIndex(id);
         if (buttonUp) theHold.Begin();
         Color curColor(cs[n]->GetColor());
         pShader->SetDiffuseClr(curColor, curTime);
         if (buttonUp) {
            theHold.Accept(GetString(IDS_DS_PARAMCHG));
            // DS: 5/11/99-  this was commented out. I put it back in, because
            // it is necessary for the Reset button in the color picker to
            // update the viewport.
            UpdateMtlDisplay();
            }
      } break;
      case WM_PAINT:
         if (!valid) {
            valid = TRUE;
            ReloadDialog();
            }
         return FALSE;
      case WM_CLOSE:
      case WM_DESTROY:
         break;
      case CC_SPINNER_CHANGE:
         if (!theHold.Holding()) theHold.Begin();
         switch (id) {
            case IDC_GL_SPIN:
               pShader->SetGlossiness(PcToFrac( glSpin->GetIVal() ), curTime);
               UpdateHilite();
               break;
            case IDC_MT_SPIN:
               pShader->SetMetalness(PcToFrac(mtSpin->GetIVal()), curTime);
               break;
            //******** >>>><<<< required handling for opacity....must be present in all dialogs
            case IDC_TR_SPIN:
               pMtl->SetOpacity(PcToFrac( trSpin->GetIVal()),curTime);
               break;
         }
//       UpdateMtlDisplay();
      break;

      case CC_SPINNER_BUTTONDOWN:
         theHold.Begin();
         break;

      case WM_CUSTEDIT_ENTER:
      case CC_SPINNER_BUTTONUP:
         if (HIWORD(wParam) || msg==WM_CUSTEDIT_ENTER)
            theHold.Accept(GetString(IDS_DS_PARAMCHG));
         else
            theHold.Cancel();
         UpdateMtlDisplay();
         break;

    }
   exit:
   return FALSE;
   }