C++ QVector::Dot方法代码示例

//does not check inside sphere
float Unit::querySphereNoRecurse( const QVector &start, const QVector &end, float min_radius ) const
{
    int    i;
    double tmp;
    for (i = 0; i < nummesh(); i++) {
        if ( ( meshdata[i]->Position().Magnitude() > this->rSize() ) || ( meshdata[i]->rSize() > 30+this->rSize() ) )
            continue;
        if (isUnit() == PLANETPTR && i > 0)
            break;
        double  a, b, c;
        QVector st  = start-Transform( cumulative_transformation_matrix, meshdata[i]->Position().Cast() );

        QVector dir = end-start;         //now start and end are based on mesh's position
        c = st.Dot( st );
        double temp1 = ( min_radius+meshdata[i]->rSize() );
        //if (st.MagnitudeSquared()<temp1*temp1) //UNCOMMENT if you want inside sphere to count...otherwise...
        //return 1.0e-6;
        if (min_radius != -FLT_MAX)
            c = c-temp1*temp1;
        else
            c = temp1;
#ifdef VARIABLE_LENGTH_PQR
        c *= SizeScaleFactor*SizeScaleFactor;
#endif
        b  = 2.0f*( dir.Dot( st ) );
        a  = dir.Dot( dir );
        //b^2-4ac
        if (min_radius != -FLT_MAX)
            c = b*b-4.0f*a*c;
        else
            c = FLT_MAX;
        if (c < 0 || a == 0)
            continue;
        a  *= 2.0f;

        tmp = ( -b+sqrt( c ) )/a;
        c   = ( -b-sqrt( c ) )/a;
        if (tmp > 0 && tmp <= 1)
            return (c > 0 && c < tmp) ? c : tmp;
        else if (c > 0 && c <= 1)
            return c;
    }
    return 0.0f;
}

float globQueryShell( QVector st, QVector dir, float radius )
{
    float temp1 = radius;
    float a, b, c;
    c  = st.Dot( st );
    c  = c-temp1*temp1;
    b  = 2.0f*( dir.Dot( st ) );
    a  = dir.Dot( dir );
    //b^2-4ac
    c  = b*b-4.0f*a*c;
    if (c < 0 || a == 0)
        return 0.0f;
    a *= 2.0f;

    float tmp = ( -b+sqrt( c ) )/a;
    c  = ( -b-sqrt( c ) )/a;
    if (tmp > 0 && tmp <= 1)
        return (c > 0 && c < tmp) ? c : tmp;
    else if (c > 0 && c <= 1)
        return c;
    return 0.0f;
}

/** queries the bounding box, excluding a select edge 
 *  0 = lx, 1=mx, 2=ly 3=my 4=lz 5=mz
 */
bool BoundingBox::OpenWithin (const QVector &query, float err, int excludeWhich) {
  err = -err;
  QVector tquery (query -lx); // now it's in coords with respect to the minimum x;
  QVector tmp (mx-lx);
  if (excludeWhich!=0){
    if (tquery.Dot (tmp) <err) {
      //VSFileSystem::Fprintf (stderr,"tqueryreturn mx-lx%f Exc %d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  if (excludeWhich!=0) {
    tquery = query - mx;
    tmp = lx - mx;
    if (tquery.Dot(tmp)<err){
      //VSFileSystem::Fprintf (stderr,"tqueryreturn lx-mx, %fExc %d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  if (excludeWhich!=1) {
    tquery = query - ly;
    tmp = my - ly;
    if (tquery.Dot (tmp)<err) {
      //VSFileSystem::Fprintf (stderr,"tqueryreturn my-ly%f Exc %d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  if (excludeWhich!=1) {
    tquery = query - my;
    tmp = ly - my;
    if (tquery.Dot (tmp) <err) {
      //VSFileSystem::Fprintf (stderr,"tqueryreturn ly-my%f Exc %d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  if (excludeWhich!=2) {
    tquery = query - lz;
    tmp = mz - lz;
    if (tquery.Dot (tmp)<err) {
      //VSFileSystem::Fprintf (stderr,"tqueryreturn mz-lz%f Exc%d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  if (excludeWhich!=2) {
    tquery = query - mz;
    tmp = lz - mz;
    if (tquery.Dot (tmp) <err) {
      //VSFileSystem::Fprintf (stderr,"tqueryreturn lz-mz%f Ignore%d\n",tquery.Dot(tmp),excludeWhich);
      return false;
    }
  }
  return true; //within bounding box;
}

/** Queries the bounding box whether the query vector is within it*/
bool BoundingBox::Within (const QVector &query, float err) {
  err = -err;
  QVector tquery =query -lx; // now it's in coords with respect to the minimum x;
  QVector tmp = mx-lx;
  if (tquery.Dot (tmp) <err) {
    //VSFileSystem::Fprintf (stderr,"tqueryreturn mx-lx%f",tquery.Dot(tmp));
    return false;
  }
  tquery = query - mx;
  tmp = lx - mx;
  if (tquery.Dot(tmp)<err){
    //VSFileSystem::Fprintf (stderr,"tqueryreturn lx-mx, %f",tquery.Dot(tmp));
    return false;
  }
  tquery = query - ly;
  tmp = my - ly;
  if (tquery.Dot (tmp)<err) {
    //VSFileSystem::Fprintf (stderr,"tqueryreturn my-ly%f",tquery.Dot(tmp));
    return false;
  }
  tquery = query - my;
  tmp = ly - my;
  if (tquery.Dot (tmp) <err) {
    //VSFileSystem::Fprintf (stderr,"tqueryreturn ly-my%f",tquery.Dot(tmp));
    return false;
  }
  tquery = query - lz;
  tmp = mz - lz;
  if (tquery.Dot (tmp)<err) {
    //VSFileSystem::Fprintf (stderr,"tqueryreturn mz-lz%f",tquery.Dot(tmp));
    return false;
  }
  tquery = query - mz;
  tmp = lz - mz;
  if (tquery.Dot (tmp) <err) {
    //VSFileSystem::Fprintf (stderr,"tqueryreturn lz-mz%f",tquery.Dot(tmp));
    return false;
  }
  return true; //within bounding box;
}

/*  Determines whether the ray intersects the box...returns -1 if the -ray does, 1 if
 *  the ray itself does. 0 if the ray misses the box
 *  To Compute the intersection of a ray from eye to pnt and a bounding box
 *  solve for 'r' 
 *  (r* pnt.i+eye.i-PlaneAffine.i) *PlaneNorm.i +
 *  (r* pnt.j+eye.j-PlaneAffine.j) *PlaneNorm.j +
 *  (r* pnt.k+eye.k-PlaneAffine.k) *PlaneNorm.k ==0 
 *  
 *  r (pnt.i*PlaneNorm.i+pnt.j*PlaneNorm.j+pnt.k*PlaneNorm.k) ==
 *  (PlaneAffine.i-eye.i)*PlaneNorm.i +(PlaneAffine.j-eye.j)*PlaneNorm.j+(PlaneAffine.k-eye.k)*PlaneNorm.k
 *  r =   pnt.Dot (PlaneNorm)/PlaneNorm.Dot(PlaneAffine-eye) 
 *  xyz = r * pnt + eye;
 */
int BoundingBox::Intersect (const QVector &eye, const QVector &pnt,float err) {
  QVector IntersectXYZ (eye.i,eye.j,eye.k);
  QVector Normal (mx - lx);
  double divisor=pnt.Dot (Normal);
  if (divisor!=0) {
    IntersectXYZ+= (Normal.Dot(lx-eye)/divisor)*pnt;//point of intersection with lx plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,0)) 
      return Normal.Dot(lx-eye)*divisor>=0?1:-1;
  }
  Normal = -Normal;  
  divisor=pnt.Dot(Normal);
  if (divisor!=0) {
    IntersectXYZ = eye+( Normal.Dot(mx-eye)/divisor)*pnt; //point of interscetion with mx plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,0)) 
      return Normal.Dot(mx-eye)*divisor>=0?1:-1;
  }
  Normal = my - ly;
  divisor = pnt.Dot(Normal);
  if (divisor!=0) {
    IntersectXYZ = eye + (Normal.Dot(ly-eye)/divisor)*pnt;//point of intersection with the ly plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,1))
      return Normal.Dot(ly-eye)*divisor>=0?1:-1;
  }
  Normal = -Normal;
  divisor = pnt.Dot(Normal);
  if (divisor!=0) {

    IntersectXYZ = eye + (Normal.Dot(my-eye)/divisor)*pnt;//point of intersection with my plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,1)) 
      return Normal.Dot(my-eye)*divisor>=0?1:-1;
  }
  Normal = (mz - lz);
  divisor = pnt.Dot(Normal);
  if (divisor!=0) {
    IntersectXYZ = eye + (Normal.Dot(lz-eye)/divisor)*pnt;//point of intersection with the ly plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,2)) 
      return Normal.Dot(lz-eye)*divisor>=0?1:-1;
  }

  Normal = -Normal;
  divisor = pnt.Dot(Normal);
  if (divisor!=0) {
    IntersectXYZ = eye + (Normal.Dot (mz-eye)/divisor)*pnt;//point of intersection with my plane
    //VSFileSystem::Fprintf (stderr,"Intersect::%f,%f,%f>\n",IntersectXYZ.i,IntersectXYZ.j,IntersectXYZ.k);
    if (OpenWithin (IntersectXYZ,err,2)) 
      return Normal.Dot(mz-eye)*divisor>=0?1:-1;
  }
  return false;
}