CWE-ou-minkata/Sources/Plasma/PubUtilLib/plScene/plCullPoly.cpp

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*==LICENSE==*/

#include "hsTypes.h"
#include "plCullPoly.h"
#include "hsMatrix44.h"
#include "hsStream.h"
#include "hsFastMath.h"

plCullPoly& plCullPoly::InitFromVerts(UInt32 f)
{
    fFlags = f;

    hsAssert(fVerts.GetCount() > 2, "Initializing from degenerate poly");

    hsVector3 a;
    hsVector3 b;
    a.Set(&fVerts[1], &fVerts[0]);
    b.Set(&fVerts[2], &fVerts[0]);
    fNorm = a % b;
    hsFastMath::Normalize(fNorm);
    fDist = -(fNorm.InnerProduct(fVerts[0]));

    fCenter.Set(0,0,0);
    int i;
    for( i = 0; i < fVerts.GetCount(); i++ )
    {
        fCenter += fVerts[i];
    }
    fCenter *= 1.f / hsScalar(fVerts.GetCount());

    fRadius = ICalcRadius();

    return *this;
}

hsScalar plCullPoly::ICalcRadius() const
{
    hsScalar radSq = 0;
    int i;
    for( i = 0; i < fVerts.GetCount(); i++ )
    {
        hsScalar tmpSq = hsVector3(&fVerts[i], &fCenter).MagnitudeSquared();
        if( tmpSq > radSq )
            radSq = tmpSq;
    }
    return radSq * hsFastMath::InvSqrt(radSq);
}

plCullPoly& plCullPoly::Flip(const plCullPoly& p)
{
    fFlags = p.fFlags;

    fNorm = -p.fNorm;
    fDist = -p.fDist;
    fCenter = p.fCenter;
    fRadius = p.fRadius;

    int n = p.fVerts.GetCount();
    fVerts.SetCount(n);
    int i;
    for( i = 0; i < n; i++ )
        fVerts[n-i-1] = p.fVerts[i];

    return *this;
}

plCullPoly& plCullPoly::Transform(const hsMatrix44& l2w, const hsMatrix44& w2l, plCullPoly& dst) const
{
    hsMatrix44 tpose;
    w2l.GetTranspose(&tpose);

    dst.fFlags = fFlags;

    dst.fVerts.SetCount(fVerts.GetCount());

    int i;
    for( i = 0; i < fVerts.GetCount(); i++ )
    {
        dst.fVerts[i] = l2w * fVerts[i];
    }
    dst.fCenter = l2w * fCenter;

    dst.fNorm = tpose * fNorm;
    
    dst.fDist = -(dst.fNorm .InnerProduct(dst.fVerts[0]));

    ICalcRadius();

    return dst;
}

void plCullPoly::Read(hsStream* s, hsResMgr* mgr)
{
    fFlags = s->ReadLE32();

    fNorm.Read(s);
    fDist = s->ReadLEScalar();
    fCenter.Read(s);

    fRadius = s->ReadLEScalar();

    int n = s->ReadLE32();
    fVerts.SetCount(n);
    int i;
    for( i = 0; i < n; i++ )
        fVerts[i].Read(s);
}

void plCullPoly::Write(hsStream* s, hsResMgr* mgr)
{
    s->WriteLE32(fFlags);

    fNorm.Write(s);
    s->WriteLEScalar(fDist);
    fCenter.Write(s);

    s->WriteLEScalar(fRadius);

    s->WriteLE32(fVerts.GetCount());
    int i;
    for( i = 0; i < fVerts.GetCount(); i++ )
        fVerts[i].Write(s);
}

#ifdef HS_DEBUGGING
#define MF_VALIDATE_POLYS
#endif // HS_DEBUGGING

#ifdef MF_VALIDATE_POLYS
hsBool plCullPoly::Validate() const
{
    const hsScalar kMinMag = 1.e-8f;
    hsScalar magSq = fNorm.MagnitudeSquared();
    if( magSq < kMinMag )
        return false;
    if( fVerts.GetCount() < 3 )
        return false;
    hsVector3 norm = hsVector3(&fVerts[1], &fVerts[0]) % hsVector3(&fVerts[2], &fVerts[0]);
    magSq = norm.MagnitudeSquared();
    if( magSq < kMinMag )
        return false;
    norm *= hsFastMath::InvSqrtAppr(magSq);
    int i;
    for( i = 3; i < fVerts.GetCount(); i++ )
    {
        hsVector3 nextNorm = hsVector3(&fVerts[i-1], &fVerts[0]) % hsVector3(&fVerts[i], &fVerts[0]);
        magSq = nextNorm.MagnitudeSquared();
        if( magSq < kMinMag )
            return false;
        nextNorm *= hsFastMath::InvSqrtAppr(magSq);
        if( nextNorm.InnerProduct(norm) < kMinMag )
            return false;
    }
    return true;
}
#else // MF_VALIDATE_POLYS
hsBool plCullPoly::Validate() const
{
    return true;
}
#endif // MF_VALIDATE_POLYS