mgcbeziertriangle3.cpp

《3D游戏引擎设计》的源码

            kSubBP.m_aakThh[2] = kThh12;
        }

        SubdivideLL(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);

        // subtriangle <(s0,tm),(sm,tm),(s0,t1)>
        kSubBP.m_uiI0 = uiI02;
        kSubBP.m_uiI1 = uiI12;
        kSubBP.m_uiI2 = rkBP.m_uiI2;
        kSubBP.m_aakXuu[0] = kXuu02;
        kSubBP.m_aakXuu[1] = kXuu12;
        kSubBP.m_aakXuu[2] = rkBP.m_aakXuu[2];
        kSubBP.m_aakXvv[0] = kXvv02;
        kSubBP.m_aakXvv[1] = kXvv12;
        kSubBP.m_aakXvv[2] = rkBP.m_aakXvv[2];
        kSubBP.m_aakXhh[0] = kXhh02;
        kSubBP.m_aakXhh[1] = kXhh12;
        kSubBP.m_aakXhh[2] = rkBP.m_aakXhh[2];

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = kCuu02;
            kSubBP.m_aakCuu[1] = kCuu12;
            kSubBP.m_aakCuu[2] = rkBP.m_aakCuu[2];
            kSubBP.m_aakCvv[0] = kCvv02;
            kSubBP.m_aakCvv[1] = kCvv12;
            kSubBP.m_aakCvv[2] = rkBP.m_aakCvv[2];
            kSubBP.m_aakChh[0] = kChh02;
            kSubBP.m_aakChh[1] = kChh12;
            kSubBP.m_aakChh[2] = rkBP.m_aakChh[2];
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = kTuu02;
            kSubBP.m_aakTuu[1] = kTuu12;
            kSubBP.m_aakTuu[2] = rkBP.m_aakTuu[2];
            kSubBP.m_aakTvv[0] = kTvv02;
            kSubBP.m_aakTvv[1] = kTvv12;
            kSubBP.m_aakTvv[2] = rkBP.m_aakTvv[2];
            kSubBP.m_aakThh[0] = kThh02;
            kSubBP.m_aakThh[1] = kThh12;
            kSubBP.m_aakThh[2] = rkBP.m_aakThh[2];
        }

        SubdivideLL(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);

        // subtriangle <(sm,t0),(sm,tm),(s0,tm)>
        kSubBP.m_uiI0 = uiI01;
        kSubBP.m_uiI1 = uiI12;
        kSubBP.m_uiI2 = uiI02;
        kSubBP.m_aakXuu[0] = kXuu01;
        kSubBP.m_aakXuu[1] = kXuu12;
        kSubBP.m_aakXuu[2] = kXuu02;
        kSubBP.m_aakXvv[0] = kXvv01;
        kSubBP.m_aakXvv[1] = kXvv12;
        kSubBP.m_aakXvv[2] = kXvv02;
        kSubBP.m_aakXhh[0] = kXhh01;
        kSubBP.m_aakXhh[1] = kXhh12;
        kSubBP.m_aakXhh[2] = kXhh02;

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = kCuu01;
            kSubBP.m_aakCuu[1] = kCuu12;
            kSubBP.m_aakCuu[2] = kCuu02;
            kSubBP.m_aakCvv[0] = kCvv01;
            kSubBP.m_aakCvv[1] = kCvv12;
            kSubBP.m_aakCvv[2] = kCvv02;
            kSubBP.m_aakChh[0] = kChh01;
            kSubBP.m_aakChh[1] = kChh12;
            kSubBP.m_aakChh[2] = kChh02;
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = kTuu01;
            kSubBP.m_aakTuu[1] = kTuu12;
            kSubBP.m_aakTuu[2] = kTuu02;
            kSubBP.m_aakTvv[0] = kTvv01;
            kSubBP.m_aakTvv[1] = kTvv12;
            kSubBP.m_aakTvv[2] = kTvv02;
            kSubBP.m_aakThh[0] = kThh01;
            kSubBP.m_aakThh[1] = kThh12;
            kSubBP.m_aakThh[2] = kThh02;
        }

        SubdivideUR(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);
    }
}
//----------------------------------------------------------------------------
void MgcBezierTriangle3::SubdivideUR (unsigned int uiLevel, MgcReal fDSqr,
    MgcVector3* akX, MgcVector3* akXu, MgcVector3* akXv, MgcColor* akColor,
    MgcVector2* akTexture, BlockParameters& rkBP)
{
    /*
     i2   i1
     +----+
       \  |
         \|
          +
          i0
    */

    // subdivision indices
    unsigned int uiI12 = (rkBP.m_uiI1 + rkBP.m_uiI2) >> 1;
    unsigned int uiD12 = rkBP.m_uiI1 - rkBP.m_uiI2;
    unsigned int uiI01 = (((rkBP.m_uiI0+rkBP.m_uiI1) << 2)+uiD12*uiD12) >> 3;
    unsigned int uiI02 = uiI01 - (uiD12 >> 1);

    // vertices

    // top u-edge subdivision
    MgcVector3 kXuu12 = 0.5*(rkBP.m_aakXuu[1] + rkBP.m_aakXuu[2]);
    MgcVector3 kXvv12 = 0.5*(rkBP.m_aakXvv[1] + rkBP.m_aakXvv[2]);
    MgcVector3 kXhh12 = 0.5*(rkBP.m_aakXhh[1] + rkBP.m_aakXhh[2]);
    akX[uiI12] = 0.5*(akX[rkBP.m_uiI1] + akX[rkBP.m_uiI2] - fDSqr*kXuu12);

    // right v-edge subdivision
    MgcVector3 kXuu01 = 0.5*(rkBP.m_aakXuu[0] + rkBP.m_aakXuu[1]);
    MgcVector3 kXvv01 = 0.5*(rkBP.m_aakXvv[0] + rkBP.m_aakXvv[1]);
    MgcVector3 kXhh01 = 0.5*(rkBP.m_aakXhh[0] + rkBP.m_aakXhh[1]);
    akX[uiI01] = 0.5*(akX[rkBP.m_uiI0] + akX[rkBP.m_uiI1] - fDSqr*kXvv01);

    // hypotenuse edge subdivision
    MgcVector3 kXuu02 = 0.5*(rkBP.m_aakXuu[0] + rkBP.m_aakXuu[2]);
    MgcVector3 kXvv02 = 0.5*(rkBP.m_aakXvv[0] + rkBP.m_aakXvv[2]);
    MgcVector3 kXhh02 = 0.5*(rkBP.m_aakXhh[0] + rkBP.m_aakXhh[2]);
    akX[uiI02] = 0.5*(akX[rkBP.m_uiI0] + akX[rkBP.m_uiI2] - fDSqr*kXhh02);

    // derivatives (for normal vectors)
    if ( akXu )
    {
        // top u-edge subdivision
        akXu[uiI12] = 0.5*(akXu[rkBP.m_uiI1] + akXu[rkBP.m_uiI2] -
            fDSqr*rkBP.m_kXuuu);
        akXv[uiI12] = 0.5*(akXv[rkBP.m_uiI1] + akXv[rkBP.m_uiI2] -
            fDSqr*rkBP.m_kXuuv);

        // right v-edge subdivision
        akXu[uiI01] = 0.5*(akXu[rkBP.m_uiI0] + akXu[rkBP.m_uiI1] - 
            fDSqr*rkBP.m_kXuvv);
        akXv[uiI01] = 0.5*(akXv[rkBP.m_uiI0] + akXv[rkBP.m_uiI1] -
            fDSqr*rkBP.m_kXvvv);

        // hypotenuse edge subdivision
        akXu[uiI02] = 0.5*(akXu[rkBP.m_uiI0] + akXu[rkBP.m_uiI2] -
            fDSqr*rkBP.m_kXhhu);
        akXv[uiI02] = 0.5*(akXv[rkBP.m_uiI0] + akXv[rkBP.m_uiI2] -
            fDSqr*rkBP.m_kXhhv);
    }

    // colors
    MgcColor kCuu12, kCvv12, kChh12, kCuu01, kCvv01, kChh01, kCuu02, kCvv02,
        kChh02;
    if ( akColor )
    {
        // top u-edge subdivision
        kCuu12 = 0.5*(rkBP.m_aakCuu[1] + rkBP.m_aakCuu[2]);
        kCvv12 = 0.5*(rkBP.m_aakCvv[1] + rkBP.m_aakCvv[2]);
        kChh12 = 0.5*(rkBP.m_aakChh[1] + rkBP.m_aakChh[2]);
        akColor[uiI12] = 0.5*(akColor[rkBP.m_uiI1] + akColor[rkBP.m_uiI2] -
            fDSqr*kCuu12);

        // right v-edge subdivision
        kCuu01 = 0.5*(rkBP.m_aakCuu[0] + rkBP.m_aakCuu[1]);
        kCvv01 = 0.5*(rkBP.m_aakCvv[0] + rkBP.m_aakCvv[1]);
        kChh01 = 0.5*(rkBP.m_aakChh[0] + rkBP.m_aakChh[1]);
        akColor[uiI01] = 0.5*(akColor[rkBP.m_uiI0] + akColor[rkBP.m_uiI1] -
            fDSqr*kCvv01);

        // hypotenuse edge subdivision
        kCuu02 = 0.5*(rkBP.m_aakCuu[0] + rkBP.m_aakCuu[2]);
        kCvv02 = 0.5*(rkBP.m_aakCvv[0] + rkBP.m_aakCvv[2]);
        kChh02 = 0.5*(rkBP.m_aakChh[0] + rkBP.m_aakChh[2]);
        akColor[uiI02] = 0.5*(akColor[rkBP.m_uiI0] + akColor[rkBP.m_uiI2] -
            fDSqr*kChh02);
    }

    // textures
    MgcVector2 kTuu12, kTvv12, kThh12, kTuu01, kTvv01, kThh01, kTuu02, kTvv02,
        kThh02;
    if ( akTexture )
    {
        // top u-edge subdivision
        kTuu12 = 0.5*(rkBP.m_aakTuu[1] + rkBP.m_aakTuu[2]);
        kTvv12 = 0.5*(rkBP.m_aakTvv[1] + rkBP.m_aakTvv[2]);
        kThh12 = 0.5*(rkBP.m_aakThh[1] + rkBP.m_aakThh[2]);
        akTexture[uiI12] = 0.5*(akTexture[rkBP.m_uiI1]+akTexture[rkBP.m_uiI2]
            - fDSqr*kTuu12);

        // right v-edge subdivision
        kTuu01 = 0.5*(rkBP.m_aakTuu[0] + rkBP.m_aakTuu[1]);
        kTvv01 = 0.5*(rkBP.m_aakTvv[0] + rkBP.m_aakTvv[1]);
        kThh01 = 0.5*(rkBP.m_aakThh[0] + rkBP.m_aakThh[1]);
        akTexture[uiI01] = 0.5*(akTexture[rkBP.m_uiI0]+akTexture[rkBP.m_uiI1]
            - fDSqr*kTvv01);

        // hypotenuse edge subdivision
        kTuu02 = 0.5*(rkBP.m_aakTuu[0] + rkBP.m_aakTuu[2]);
        kTvv02 = 0.5*(rkBP.m_aakTvv[0] + rkBP.m_aakTvv[2]);
        kThh02 = 0.5*(rkBP.m_aakThh[0] + rkBP.m_aakThh[2]);
        akTexture[uiI02] = 0.5*(akTexture[rkBP.m_uiI0]+akTexture[rkBP.m_uiI2]
            - fDSqr*kThh02);
    }

    // recurse on four children
    if ( uiLevel > 0 )
    {
        uiLevel--;
        fDSqr *= 0.25;

        BlockParameters kSubBP;

        // subtriangle <(sm,tm),(sm,t1),(s0,t1)>
        kSubBP.m_uiI0 = uiI02;
        kSubBP.m_uiI1 = uiI12;
        kSubBP.m_uiI2 = rkBP.m_uiI2;
        kSubBP.m_aakXuu[0] = kXuu02;
        kSubBP.m_aakXuu[1] = kXuu12;
        kSubBP.m_aakXuu[2] = rkBP.m_aakXuu[2];
        kSubBP.m_aakXvv[0] = kXvv02;
        kSubBP.m_aakXvv[1] = kXvv12;
        kSubBP.m_aakXvv[2] = rkBP.m_aakXvv[2];
        kSubBP.m_aakXhh[0] = kXhh02;
        kSubBP.m_aakXhh[1] = kXhh12;
        kSubBP.m_aakXhh[2] = rkBP.m_aakXhh[2];

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = kCuu02;
            kSubBP.m_aakCuu[1] = kCuu12;
            kSubBP.m_aakCuu[2] = rkBP.m_aakCuu[2];
            kSubBP.m_aakCvv[0] = kCvv02;
            kSubBP.m_aakCvv[1] = kCvv12;
            kSubBP.m_aakCvv[2] = rkBP.m_aakCvv[2];
            kSubBP.m_aakChh[0] = kChh02;
            kSubBP.m_aakChh[1] = kChh12;
            kSubBP.m_aakChh[2] = rkBP.m_aakChh[2];
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = kTuu02;
            kSubBP.m_aakTuu[1] = kTuu12;
            kSubBP.m_aakTuu[2] = rkBP.m_aakTuu[2];
            kSubBP.m_aakTvv[0] = kTvv02;
            kSubBP.m_aakTvv[1] = kTvv12;
            kSubBP.m_aakTvv[2] = rkBP.m_aakTvv[2];
            kSubBP.m_aakThh[0] = kThh02;
            kSubBP.m_aakThh[1] = kThh12;
            kSubBP.m_aakThh[2] = rkBP.m_aakThh[2];
        }

        SubdivideUR(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);

        // subtriangle <(s1,tm),(s1,t1),(sm,t1)>
        kSubBP.m_uiI0 = uiI01;
        kSubBP.m_uiI1 = rkBP.m_uiI1;
        kSubBP.m_uiI2 = uiI12;
        kSubBP.m_aakXuu[0] = kXuu01;
        kSubBP.m_aakXuu[1] = rkBP.m_aakXuu[1];
        kSubBP.m_aakXuu[2] = kXuu12;
        kSubBP.m_aakXvv[0] = kXvv01;
        kSubBP.m_aakXvv[1] = rkBP.m_aakXvv[1];
        kSubBP.m_aakXvv[2] = kXvv12;
        kSubBP.m_aakXhh[0] = kXhh01;
        kSubBP.m_aakXhh[1] = rkBP.m_aakXhh[1];
        kSubBP.m_aakXhh[2] = kXhh12;

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = kCuu01;
            kSubBP.m_aakCuu[1] = rkBP.m_aakCuu[1];
            kSubBP.m_aakCuu[2] = kCuu12;
            kSubBP.m_aakCvv[0] = kCvv01;
            kSubBP.m_aakCvv[1] = rkBP.m_aakCvv[1];
            kSubBP.m_aakCvv[2] = kCvv12;
            kSubBP.m_aakChh[0] = kChh01;
            kSubBP.m_aakChh[1] = rkBP.m_aakChh[1];
            kSubBP.m_aakChh[2] = kChh12;
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = kTuu01;
            kSubBP.m_aakTuu[1] = rkBP.m_aakTuu[1];
            kSubBP.m_aakTuu[2] = kTuu12;
            kSubBP.m_aakTvv[0] = kTvv01;
            kSubBP.m_aakTvv[1] = rkBP.m_aakTvv[1];
            kSubBP.m_aakTvv[2] = kTvv12;
            kSubBP.m_aakThh[0] = kThh01;
            kSubBP.m_aakThh[1] = rkBP.m_aakThh[1];
            kSubBP.m_aakThh[2] = kThh12;
        }

        SubdivideUR(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);

        // subtriangle <(s1,t0),(s1,tm),(sm,tm)>
        kSubBP.m_uiI0 = rkBP.m_uiI0;
        kSubBP.m_uiI1 = uiI01;
        kSubBP.m_uiI2 = uiI02;
        kSubBP.m_aakXuu[0] = rkBP.m_aakXuu[0];
        kSubBP.m_aakXuu[1] = kXuu01;
        kSubBP.m_aakXuu[2] = kXuu02;
        kSubBP.m_aakXvv[0] = rkBP.m_aakXvv[0];
        kSubBP.m_aakXvv[1] = kXvv01;
        kSubBP.m_aakXvv[2] = kXvv02;
        kSubBP.m_aakXhh[0] = rkBP.m_aakXhh[0];
        kSubBP.m_aakXhh[1] = kXhh01;
        kSubBP.m_aakXhh[2] = kXhh02;

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = rkBP.m_aakCuu[0];
            kSubBP.m_aakCuu[1] = kCuu01;
            kSubBP.m_aakCuu[2] = kCuu02;
            kSubBP.m_aakCvv[0] = rkBP.m_aakCvv[0];
            kSubBP.m_aakCvv[1] = kCvv01;
            kSubBP.m_aakCvv[2] = kCvv02;
            kSubBP.m_aakChh[0] = rkBP.m_aakChh[0];
            kSubBP.m_aakChh[1] = kChh01;
            kSubBP.m_aakChh[2] = kChh02;
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = rkBP.m_aakTuu[0];
            kSubBP.m_aakTuu[1] = kTuu01;
            kSubBP.m_aakTuu[2] = kTuu02;
            kSubBP.m_aakTvv[0] = rkBP.m_aakTvv[0];
            kSubBP.m_aakTvv[1] = kTvv01;
            kSubBP.m_aakTvv[2] = kTvv02;
            kSubBP.m_aakThh[0] = rkBP.m_aakThh[0];
            kSubBP.m_aakThh[1] = kThh01;
            kSubBP.m_aakThh[2] = kThh02;
        }

        SubdivideUR(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);

        // subtriangle <(sm,tm),(s1,tm),(sm,t1)>
        kSubBP.m_uiI0 = uiI02;
        kSubBP.m_uiI1 = uiI01;
        kSubBP.m_uiI2 = uiI12;
        kSubBP.m_aakXuu[0] = kXuu02;
        kSubBP.m_aakXuu[1] = kXuu01;
        kSubBP.m_aakXuu[2] = kXuu12;
        kSubBP.m_aakXvv[0] = kXvv02;
        kSubBP.m_aakXvv[1] = kXvv01;
        kSubBP.m_aakXvv[2] = kXvv12;
        kSubBP.m_aakXhh[0] = kXhh02;
        kSubBP.m_aakXhh[1] = kXhh01;
        kSubBP.m_aakXhh[2] = kXhh12;

        if ( akColor )
        {
            kSubBP.m_aakCuu[0] = kCuu02;
            kSubBP.m_aakCuu[1] = kCuu01;
            kSubBP.m_aakCuu[2] = kCuu12;
            kSubBP.m_aakCvv[0] = kCvv02;
            kSubBP.m_aakCvv[1] = kCvv01;
            kSubBP.m_aakCvv[2] = kCvv12;
            kSubBP.m_aakChh[0] = kChh02;
            kSubBP.m_aakChh[1] = kChh01;
            kSubBP.m_aakChh[2] = kChh12;
        }

        if ( akTexture )
        {
            kSubBP.m_aakTuu[0] = kTuu02;
            kSubBP.m_aakTuu[1] = kTuu01;
            kSubBP.m_aakTuu[2] = kTuu12;
            kSubBP.m_aakTvv[0] = kTvv02;
            kSubBP.m_aakTvv[1] = kTvv01;
            kSubBP.m_aakTvv[2] = kTvv12;
            kSubBP.m_aakThh[0] = kThh02;
            kSubBP.m_aakThh[1] = kThh01;
            kSubBP.m_aakThh[2] = kThh12;
        }

        SubdivideLL(uiLevel,fDSqr,akX,akXu,akXv,akColor,akTexture,kSubBP);
    }
}
//----------------------------------------------------------------------------

//---------------------------------------------------------------------------
// streaming
//---------------------------------------------------------------------------
MgcObject* MgcBezierTriangle3::Factory (MgcStream& rkStream)
{
    MgcBezierTriangle3* pkObject = new MgcBezierTriangle3;
    MgcStream::Link* pkLink = new MgcStream::Link(pkObject);
    pkObject->Load(rkStream,pkLink);
    return pkObject;
}
//---------------------------------------------------------------------------
void MgcBezierTriangle3::Load (MgcStream& rkStream, MgcStream::Link* pkLink)
{
    MgcBezierTriangle::Load(rkStream,pkLink);
}
//---------------------------------------------------------------------------
void MgcBezierTriangle3::Link (MgcStream& rkStream, MgcStream::Link* pkLink)
{
    MgcBezierTriangle::Link(rkStream,pkLink);
}
//---------------------------------------------------------------------------
bool MgcBezierTriangle3::Register (MgcStream& rkStream)
{
    return MgcBezierTriangle::Register(rkStream);
}
//---------------------------------------------------------------------------
void MgcBezierTriangle3::Save (MgcStream& rkStream)
{
    MgcBezierTriangle::Save(rkStream);
}
//---------------------------------------------------------------------------