C++ ShadeContext::Light方法代码示例

void DumMtl::Shade(ShadeContext& sc)
{
	Color lightCol;
	Color diffwk(0.0f,0.0f,0.0f);
	Color specwk(0.0f,0.0f,0.0f);
	Point3 N = sc.Normal();
	Point3	R = sc.ReflectVector();
	LightDesc *l;
	for (int i = 0; i<sc.nLights; i++) {
		l = sc.Light(i);
		register float NL, diffCoef;
		Point3 L;
		if (!l->Illuminate(sc, N, lightCol, L, NL, diffCoef))
			continue;

		// diffuse
		if (l->affectDiffuse)
			diffwk += diffCoef*lightCol;
		// specular
		if (l->affectSpecular) {
			float c = DotProd(L,R);
			if (c>0.0f) {
				c = (float)pow((double)c, (double)phongexp); 
				specwk += c*lightCol*NL;   // multiply by NL to SOFTEN 
			}
		}
	}
	sc.out.t = Color(0.0f,0.0f,0.0f);
	sc.out.c = (.3f*sc.ambientLight + diffwk)*diff + specwk*spec;		
}

// if this function changes, please also check SupportsReShading, PreShade and PostShade
// end - ke/mjm - 03.16.00 - merge reshading code
// [attilas|29.5.2000] if this function changes, please also check EvalColorStdChannel
void Matte::Shade(ShadeContext& sc)
{
   Color c,t, shadowClr;
   float atten;
   float reflA;

   // > 6/15/02 - 11:12am --MQM-- 
   // for renderer prepass, we need to at least call
   // illuminate so that Light Tracer can cache shading
   if ( SHADECONTEXT_IS_PREPASS( sc ) )
   {
      Color    lightCol;
      Point3   L;
      float    NL = 0.0f, diffCoef = 0.0f;
      LightDesc *l = NULL;
      for ( int i = 0;  i < sc.nLights;  i++ )
      {
         l = sc.Light( i );
         if ( NULL != l )
            l->Illuminate( sc, sc.Normal(), lightCol, L, NL, diffCoef );
      }
      return;
   }

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

   if (gbufID) sc.SetGBufferID(gbufID);
   IllumParams ip( 1, &shadowIllumOutStr);
   IllumParams ipNS(0, NULL);
   ip.ClearInputs(); ip.ClearOutputs();
   ipNS.ClearInputs(); ipNS.ClearOutputs();
   ip.hasComponents = ipNS.hasComponents = HAS_MATTE_MTL; 
   
   // get background color & transparency
   if (!opaque) sc.Execute(0x1000); // DS: 6/24/99:use black bg when AA filtering (#192348)
   sc.GetBGColor(c, t, fogBG&&(!fogObjDepth) );
   if (!opaque) sc.Execute(0x1001); // DS: 6/24/99:use black bg when AA filtering (#192348)

   if (shadowBG && sc.shadow) {
      /********
      sc.shadow = 0;
      Color col0 = sc.DiffuseIllum();
      sc.shadow = 1;
      Color scol = sc.DiffuseIllum();
      float f = Intens(col0);
      atten = (f>0.0f)?Intens(scol)/f:1.0f;
      if (atten>1.0f) atten = 1.0f/atten;
      ********/
      atten = IllumShadow( sc, shadowClr );
      atten = amblev + (1.0f-amblev) * atten; 

      // key on black user-set shadow clr
      if( gUseLocalShadowClr || col.r != 0.0f || col.g != 0.0f || col.b != 0.0f )
            shadowClr = col;

      ipNS.finalC = ipNS.diffIllumOut = c;
      c *= atten;
      ip.diffIllumOut = c;

      shadowClr *= 1.0f - atten;
      ip.finalC = sc.out.c = c + shadowClr;

      ip.SetUserIllumOutput( 0, shadowClr );

      if (shadowAlpha)
         t *= atten;
   } else {
      sc.out.c  = 
      ipNS.finalC = ipNS.diffIllumOut = ip.finalC = ip.diffIllumOut = c;
   }


   // add the reflections
   if (reflmap && useReflMap) {
      AColor rcol;
      if (reflmap->HandleOwnViewPerturb()) {
         sc.TossCache(reflmap);
         rcol = reflmap->EvalColor(sc);
      } else 
         rcol = sc.EvalEnvironMap(reflmap, sc.ReflectVector());

      Color rc;
      rc = Color(rcol.r,rcol.g,rcol.b)*reflAmt;
      ip.reflIllumOut = ipNS.reflIllumOut = rc;

      if( additiveReflection ) {
         // additive compositing of reflections
         sc.out.c += rc; ip.finalC += rc; ipNS.finalC += rc;
      } else {
         reflA = Intens( rc );
         // over compositing of reflections 
         sc.out.c = (1.0f - reflA) * sc.out.c + rc; 
         ip.finalC = (1.0f - reflA) * ip.finalC + rc;
//.........这里部分代码省略.........

// returns shadow fraction & shadowClr
// move this util to shade context at first opportunity
float IllumShadow( ShadeContext& sc, Color& shadowClr ) 
{ 
   IlluminateComponents illumComp;
   IIlluminationComponents* pIComponents = NULL; 
   Color illumClr(0,0,0);
   Color illumClrNS(0,0,0);
   shadowClr.Black();
   Point3 N = sc.Normal();

   // scale the sums so we don't overflow
// float scaleFactor = 1.0;
// if( sc.nLights )
//    scaleFactor = 1.0f / float( sc.nLights );

   // > 9/24/02 - 2:30pm --MQM-- 
   // poke flag to let Light Tracer/Radiosity so they will
   // separate out the shadow value.   
   int oldXID = sc.xshadeID;
   sc.xshadeID |= SHADECONTEXT_GUESS_SHADOWS_FLAG;
   
   for (int i = 0; i < sc.nLights; i++) {
      LightDesc* l = sc.Light( i );
      pIComponents = (IIlluminationComponents*)l->GetInterface( IID_IIlluminationComponents );
      if( pIComponents ){
         // use component wise illuminate routines
         if (!pIComponents->Illuminate( sc, N, illumComp ))
            continue;

//       illumClr += (illumComp.finalColor - illumComp.shadowColor ) * illumComp.geometricAtten * scaleFactor;
         LBound( illumComp.shadowColor );
         illumClr += (illumComp.finalColor - illumComp.shadowColor ) * illumComp.geometricAtten;
//       illumClrNS += illumComp.finalColorNS * illumComp.geometricAtten * scaleFactor;
         illumClrNS += illumComp.finalColorNS * illumComp.geometricAtten;
         if( illumComp.rawColor != illumComp.filteredColor ){
            // light is filtered by a transparent object, sum both filter & user shadow color
            shadowClr += illumComp.finalColor * illumComp.geometricAtten; //attenuated filterColor 
         } else {
            // no transparency, sum in just the shadow color
            shadowClr += illumComp.shadowColor * illumComp.geometricAtten;
         }

      } else {
         // no component interface, shadow clr is black
         Color lightCol;
         Point3 L;
         register float NL, diffCoef;
         if (!l->Illuminate(sc, N, lightCol, L, NL, diffCoef))
            continue;
         if (diffCoef <= 0.0f)     
            continue;
//       illumClr += diffCoef * lightCol * scaleFactor;
         illumClr += diffCoef * lightCol;

         if( sc.shadow ){
            sc.shadow = FALSE;
            l->Illuminate(sc, N, lightCol, L, NL, diffCoef);
//          illumClrNS += diffCoef * lightCol * scaleFactor;
            illumClrNS += diffCoef * lightCol;
            sc.shadow = TRUE;
         } else {
            illumClrNS = illumClr;
         }
      }
   }// end, for each light

   // > 9/24/02 - 2:31pm --MQM-- 
   // restore xshadeID
   sc.xshadeID = oldXID;

   float intensNS = Intens(illumClrNS);
// Clamp( intensNS );
   float intens = Intens(illumClr);
// Clamp( intens );
   float atten = (intensNS > 0.01f)? intens/intensNS : 1.0f;
   if (atten > 1.0f)
      atten = 1.0f/atten;

   return atten;
}

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

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

	// Blinn style phong
	BOOL isShiny= (ip.channels[ID_SS].r > 0.0f) ? 1 : 0; 
	double phExp = 0.0;
	if (isShiny)
		phExp = pow(2.0, ip.channels[ID_SH].r * 10.0) * 4.0; 

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

			// specular  
			Color spec( 0.0f, 0.0f, 0.0f );
			if (isShiny && l->affectSpecular) {
				Point3 H = Normalize(L-sc.V() ); // (L + -V)/2
				float c = DotProd(sc.Normal(), H);	 
				if (c>0.0f) {
					if (softThresh != 0.0 && kL < softThresh) {
						c *= Soften(kL/softThresh);
					}
					c = (float)pow((double)c, phExp); // could use table lookup for speed
					spec = c * ip.channels[ID_SS].r * lightCol;
					ip.specIllumOut += spec;
				}
			}

			// diffuse
			if (l->affectDiffuse){
				float diffIntens;
				Color d = OrenNayarIllum( sc.Normal(), L, sc.V(), ip.channels[ID_DIFF_ROUGH].r * Pi*0.5f, ip.channels[ID_DI], &diffIntens, NL );
				d = d * ip.channels[ID_DIFF_LEV].r; 
				ip.diffIllumOut += kL * d * lightCol;
				ip.diffIllumIntens += kL * diffIntens * Intens(lightCol);
			}
 		}
	} // for each light

	// Apply mono self illumination
	if ( ! selfIllumClrOn ){
		float si = 0.3333333f * (ip.channels[ID_SI].r + ip.channels[ID_SI].g + ip.channels[ID_SI].b);
//		float si = ip.channels[ID_SI].r;  //DS: 4/23/99
		if ( si > 0.0f ) {
			si = Bound( si );
			ip.selfIllumOut = si * ip.channels[ID_DI];
			ip.diffIllumOut *= (1.0f - si);
			// fade the ambient down on si: 5/27/99 ke
			ip.ambIllumOut *= 1.0f-si;
			}
		}
	else {
	// colored self illum, 
		ip.selfIllumOut += ip.channels[ID_SI];
	}

	
	// get the diffuse intensity...unscramble the wavelength dependence
//	float rho, diffIntens;
//	rho = ip.channels[ID_DI].r == 0.0f ? 1.0f : 1.0f / ip.channels[ID_DI].r;
//	diffIntens = ip.diffIllumOut.r * rho;
//	rho = ip.channels[ID_DI].g == 0.0f ? 1.0f : 1.0f / ip.channels[ID_DI].g;
//	diffIntens += ip.diffIllumOut.g * rho;
//	rho = ip.channels[ID_DI].b == 0.0f ? 1.0f : 1.0f / ip.channels[ID_DI].b;
//	diffIntens += ip.diffIllumOut.b * rho;
//	ip.diffIllumIntens = diffIntens * 0.5f;
	// now we can multiply by the clrs
	ip.specIllumOut *= ip.channels[ID_SP]; 
	ip.ambIllumOut *= ip.channels[ID_AM]; 

	int chan = ip.stdIDToChannel[ ID_RR ];
	ShadeTransmission(sc, ip, ip.channels[chan], ip.refractAmt);
	chan = ip.stdIDToChannel[ ID_RL ];
	ShadeReflection( sc, ip, ip.channels[chan] ); 

	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);
	}

//.........这里部分代码省略.........

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);   
//.........这里部分代码省略.........

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

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

	BOOL isShiny= (ip.channels[W_SL].r > 0.0f) ? 1 : 0; 

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

			// diffuse
			if (l->affectDiffuse){
				ip.diffIllumOut += Kl / Pi * ip.channels[W_DL].r * lightCol;
			}

			// specular  
			if (isShiny && l->affectSpecular) {
				float gx = ip.channels[W_GX].r;
				float gy = ip.channels[W_GY].r;
				assert( gx >= 0.0f && gy >= 0.0f );
				Point3 H = Normalize(L - sc.V() ); // (L + -V)/2
				float NH = DotProd(sc.Normal(), H);	 
				if (NH > 0.0f) {
					float g2 = normalizeOn ? gx * gy : DEFAULT_GLOSS2;
					float norm = 1.0f / (4.0f * PI * g2);
					float NV = -DotProd(sc.Normal(), sc.V() );
					if ( NV <= 0.001f)
						NV = 0.001f;
  
					float g = 1.0f / (float)sqrt( NL * NV );
					if ( g > 6.0f ) g = 6.0f;

					
					//Point3 basisVecs[ 3 ];
					//sc.DPdUVW( basisVecs, uvChan ); // 0 is vtxclr, 1..n is uv channels, max_meshmaps in mesh.h
					//basisVecs[0] = Normalize( basisVecs[0] );

					// This is the new preferred method for getting bump basis vectors -- DS 5/22/00
					Point3 basisVecs[2];
					sc.BumpBasisVectors(basisVecs, 0, uvChan);

					// the line between the tip of vec[0] and its projection on N is tangent
					Point3 T = basisVecs[0] - sc.Normal() * Dot( basisVecs[0], sc.Normal() );
					Point3 B = CrossProd( sc.Normal(), T );
					float x = DotProd( H, T ) / gx;
					float y = DotProd( H, B ) / gy;
					float e = (float)exp( -2.0 * (x*x + y*y) / (1.0+NH) );
					ip.specIllumOut += Kl * ip.channels[W_SL].r * norm * g * e * lightCol;
				}
			}
 		}
	} // for each light

	// now we can multiply by the clrs, 
	ip.ambIllumOut *= ip.channels[W_AM]; 
	ip.diffIllumIntens = Intens(ip.diffIllumOut);
	ip.diffIllumOut *= ip.channels[W_DI]; 
	ip.specIllumOut *= ip.channels[W_SP]; 

	int chan = ip.stdIDToChannel[ ID_RR ];
	ShadeTransmission(sc, ip, ip.channels[chan], ip.refractAmt);
	chan = ip.stdIDToChannel[ ID_RL ];
	ShadeReflection( sc, ip, ip.channels[chan] ); 

	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 ); 

}