// 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;
}
