自学教程：C++ transformCoords函数代码示例

QgsRectangle QgsCoordinateTransform::transform( const QgsRectangle theRect, TransformDirection direction ) const{    if ( mShortCircuit || !mInitialisedFlag )        return theRect;    // transform x    double x1 = theRect.xMinimum();    double y1 = theRect.yMinimum();    double x2 = theRect.xMaximum();    double y2 = theRect.yMaximum();    // Number of points to reproject------+    //                                    |    //                                    V    try    {        double z = 0.0;        transformCoords( 1, &x1, &y1, &z, direction );        transformCoords( 1, &x2, &y2, &z, direction );    }    catch ( const QgsCsException & )    {        // rethrow the exception        QgsDebugMsg( "rethrowing exception" );        throw;    }#ifdef COORDINATE_TRANSFORM_VERBOSE    QgsDebugMsg( "Rect projection..." );    QgsDebugMsg( QString( "Xmin : %1 --> %2" ).arg( theRect.xMinimum() ).arg( x1 ) );    QgsDebugMsg( QString( "Ymin : %1 --> %2" ).arg( theRect.yMinimum() ).arg( y1 ) );    QgsDebugMsg( QString( "Xmax : %1 --> %2" ).arg( theRect.xMaximum() ).arg( x2 ) );    QgsDebugMsg( QString( "Ymax : %1 --> %2" ).arg( theRect.yMaximum() ).arg( y2 ) );#endif    return QgsRectangle( x1, y1, x2, y2 );}

void QgsCoordinateTransform::transformInPlace(    QVector<double>& x, QVector<double>& y, QVector<double>& z,    TransformDirection direction ) const{    if ( mShortCircuit || !mInitialisedFlag )        return;    Q_ASSERT( x.size() == y.size() );    // Apparently, if one has a std::vector, it is valid to use the    // address of the first element in the vector as a pointer to an    // array of the vectors data, and hence easily interface with code    // that wants C-style arrays.    try    {        transformCoords( x.size(), &x[0], &y[0], &z[0], direction );    }    catch ( const QgsCsException & )    {        // rethrow the exception        QgsDebugMsg( "rethrowing exception" );        throw;    }}

void QgsCoordinateTransform::transformInPlace(  QVector<float> &x, QVector<float> &y, QVector<float> &z,  TransformDirection direction ) const{  if ( !d->mIsValid || d->mShortCircuit )    return;  Q_ASSERT( x.size() == y.size() );  // Apparently, if one has a std::vector, it is valid to use the  // address of the first element in the vector as a pointer to an  // array of the vectors data, and hence easily interface with code  // that wants C-style arrays.  try  {    //copy everything to double vectors since proj needs double    int vectorSize = x.size();    QVector<double> xd( x.size() );    QVector<double> yd( y.size() );    QVector<double> zd( z.size() );    double *destX = xd.data();    double *destY = yd.data();    double *destZ = zd.data();    const float *srcX = x.constData();    const float *srcY = y.constData();    const float *srcZ = z.constData();    for ( int i = 0; i < vectorSize; ++i )    {      *destX++ = static_cast< double >( *srcX++ );      *destY++ = static_cast< double >( *srcY++ );      *destZ++ = static_cast< double >( *srcZ++ );    }    transformCoords( x.size(), &xd[0], &yd[0], &zd[0], direction );    //copy back    float *destFX = x.data();    float *destFY = y.data();    float *destFZ = z.data();    const double *srcXD = xd.constData();    const double *srcYD = yd.constData();    const double *srcZD = zd.constData();    for ( int i = 0; i < vectorSize; ++i )    {      *destFX++ = static_cast< float >( *srcXD++ );      *destFY++ = static_cast< float >( *srcYD++ );      *destFZ++ = static_cast< float >( *srcZD++ );    }  }  catch ( QgsCsException & )  {    // rethrow the exception    QgsDebugMsg( QStringLiteral( "rethrowing exception" ) );    throw;  }}

 QPointF Panel::transformCoords(QPointF pos) {     coord m = pos.x();     coord n = pos.y();     int x, y;     transformCoords(m, n, &x, &y);     return QPointF(x, y); }

QgsRectangle QgsCoordinateTransform::transform( const QgsRectangle theRect, TransformDirection direction ) const{  if ( mShortCircuit || !mInitialisedFlag )    return theRect;  // transform x  double x1 = theRect.xMinimum();  double y1 = theRect.yMinimum();  double x2 = theRect.xMaximum();  double y2 = theRect.yMaximum();  // Number of points to reproject------+  //                                    |  //                                    V  try  {    double z = 0.0;    transformCoords( 1, &x1, &y1, &z, direction );    transformCoords( 1, &x2, &y2, &z, direction );  }  catch ( QgsCsException &cse )  {    // rethrow the exception    QgsDebugMsg( "rethrowing exception" );    throw cse;  }#ifdef COORDINATE_TRANSFORM_VERBOSE  QgsDebugMsg( "Rect projection..." );  QgsLogger::debug( "Xmin : ", theRect.xMinimum(), 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "-->", x1, 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "Ymin : ", theRect.yMinimum(), 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "-->", y1, 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "Xmax : ", theRect.xMaximum(), 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "-->", x2, 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "Ymax : ", theRect.yMaximum(), 1, __FILE__, __FUNCTION__, __LINE__ );  QgsLogger::debug( "-->", y2, 1, __FILE__, __FUNCTION__, __LINE__ );#endif  return QgsRectangle( x1, y1, x2, y2 );}

void QgsCoordinateTransform::transformPolygon( QPolygonF &poly, TransformDirection direction ) const{  if ( !d->mIsValid || d->mShortCircuit )  {    return;  }  //create x, y arrays  int nVertices = poly.size();  QVector<double> x( nVertices );  QVector<double> y( nVertices );  QVector<double> z( nVertices );  double *destX = x.data();  double *destY = y.data();  double *destZ = z.data();  const QPointF *polyData = poly.constData();  for ( int i = 0; i < nVertices; ++i )  {    *destX++ = polyData->x();    *destY++ = polyData->y();    *destZ++ = 0;    polyData++;  }  try  {    transformCoords( nVertices, x.data(), y.data(), z.data(), direction );  }  catch ( const QgsCsException & )  {    // rethrow the exception    QgsDebugMsg( QStringLiteral( "rethrowing exception" ) );    throw;  }  QPointF *destPoint = poly.data();  const double *srcX = x.constData();  const double *srcY = y.constData();  for ( int i = 0; i < nVertices; ++i )  {    destPoint->rx() = *srcX++;    destPoint->ry() = *srcY++;    destPoint++;  }}

void QgsCoordinateTransform::transformPolygon( QPolygonF& poly, TransformDirection direction ) const{    if ( mShortCircuit || !mInitialisedFlag )    {        return;    }    //create x, y arrays    int nVertices = poly.size();    QVector<double> x( nVertices );    QVector<double> y( nVertices );    QVector<double> z( nVertices );    for ( int i = 0; i < nVertices; ++i )    {        const QPointF& pt = poly.at( i );        x[i] = pt.x();        y[i] = pt.y();        z[i] = 0;    }    try    {        transformCoords( nVertices, x.data(), y.data(), z.data(), direction );    }    catch ( const QgsCsException & )    {        // rethrow the exception        QgsDebugMsg( "rethrowing exception" );        throw;    }    for ( int i = 0; i < nVertices; ++i )    {        QPointF& pt = poly[i];        pt.rx() = x[i];        pt.ry() = y[i];    }}

QgsPointXY QgsCoordinateTransform::transform( const QgsPointXY &point, TransformDirection direction ) const{  if ( !d->mIsValid || d->mShortCircuit )    return point;  // transform x  double x = point.x();  double y = point.y();  double z = 0.0;  try  {    transformCoords( 1, &x, &y, &z, direction );  }  catch ( const QgsCsException & )  {    // rethrow the exception    QgsDebugMsg( QStringLiteral( "rethrowing exception" ) );    throw;  }  return QgsPointXY( x, y );}

QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle rect, TransformDirection direction, const bool handle180Crossover ) const{    // Calculate the bounding box of a QgsRectangle in the source CRS    // when projected to the destination CRS (or the inverse).    // This is done by looking at a number of points spread evenly    // across the rectangle    if ( mShortCircuit || !mInitialisedFlag )        return rect;    if ( rect.isEmpty() )    {        QgsPoint p = transform( rect.xMinimum(), rect.yMinimum(), direction );        return QgsRectangle( p, p );    }    static const int numP = 8;    QgsRectangle bb_rect;    bb_rect.setMinimal();    // We're interfacing with C-style vectors in the    // end, so let's do C-style vectors here too.    double x[numP * numP];    double y[numP * numP];    double z[numP * numP];    QgsDebugMsg( "Entering transformBoundingBox..." );    // Populate the vectors    double dx = rect.width()  / ( double )( numP - 1 );    double dy = rect.height() / ( double )( numP - 1 );    double pointY = rect.yMinimum();    for ( int i = 0; i < numP ; i++ )    {        // Start at right edge        double pointX = rect.xMinimum();        for ( int j = 0; j < numP; j++ )        {            x[( i*numP ) + j] = pointX;            y[( i*numP ) + j] = pointY;            // and the height...            z[( i*numP ) + j] = 0.0;            // QgsDebugMsg(QString("BBox coord: (%1, %2)").arg(x[(i*numP) + j]).arg(y[(i*numP) + j]));            pointX += dx;        }        pointY += dy;    }    // Do transformation. Any exception generated must    // be handled in above layers.    try    {        transformCoords( numP * numP, x, y, z, direction );    }    catch ( const QgsCsException & )    {        // rethrow the exception        QgsDebugMsg( "rethrowing exception" );        throw;    }    // Calculate the bounding box and use that for the extent    for ( int i = 0; i < numP * numP; i++ )    {        if ( !qIsFinite( x[i] ) || !qIsFinite( y[i] ) )        {            continue;        }        if ( handle180Crossover )        {            //if crossing the date line, temporarily add 360 degrees to -ve longitudes            bb_rect.combineExtentWith( x[i] >= 0.0 ? x[i] : x[i] + 360.0, y[i] );        }        else        {            bb_rect.combineExtentWith( x[i], y[i] );        }    }    if ( handle180Crossover )    {        //subtract temporary addition of 360 degrees from longitudes        if ( bb_rect.xMinimum() > 180.0 )            bb_rect.setXMinimum( bb_rect.xMinimum() - 360.0 );        if ( bb_rect.xMaximum() > 180.0 )            bb_rect.setXMaximum( bb_rect.xMaximum() - 360.0 );    }    QgsDebugMsg( "Projected extent: " + bb_rect.toString() );    if ( bb_rect.isEmpty() )//.........这里部分代码省略.........

QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle &rect, TransformDirection direction, const bool handle180Crossover ) const{  // Calculate the bounding box of a QgsRectangle in the source CRS  // when projected to the destination CRS (or the inverse).  // This is done by looking at a number of points spread evenly  // across the rectangle  if ( mShortCircuit || !mInitialisedFlag )    return rect;  if ( rect.isEmpty() )  {    QgsPoint p = transform( rect.xMinimum(), rect.yMinimum(), direction );    return QgsRectangle( p, p );  }  // 64 points (<=2.12) is not enough, see #13665, for EPSG:4326 -> EPSG:3574 (say that it is a hard one),  // are decent result from about 500 points and more. This method is called quite often, but  // even with 1000 points it takes < 1ms  // TODO: how to effectively and precisely reproject bounding box?  const int nPoints = 1000;  double d = sqrt(( rect.width() * rect.height() ) / pow( sqrt( static_cast< double >( nPoints ) ) - 1, 2.0 ) );  int nXPoints = static_cast< int >( ceil( rect.width() / d ) ) + 1;  int nYPoints = static_cast< int >( ceil( rect.height() / d ) ) + 1;  QgsRectangle bb_rect;  bb_rect.setMinimal();  // We're interfacing with C-style vectors in the  // end, so let's do C-style vectors here too.  QVector<double> x( nXPoints * nYPoints );  QVector<double> y( nXPoints * nYPoints );  QVector<double> z( nXPoints * nYPoints );  QgsDebugMsg( "Entering transformBoundingBox..." );  // Populate the vectors  double dx = rect.width()  / static_cast< double >( nXPoints - 1 );  double dy = rect.height() / static_cast< double >( nYPoints - 1 );  double pointY = rect.yMinimum();  for ( int i = 0; i < nYPoints ; i++ )  {    // Start at right edge    double pointX = rect.xMinimum();    for ( int j = 0; j < nXPoints; j++ )    {      x[( i*nXPoints ) + j] = pointX;      y[( i*nXPoints ) + j] = pointY;      // and the height...      z[( i*nXPoints ) + j] = 0.0;      // QgsDebugMsg(QString("BBox coord: (%1, %2)").arg(x[(i*numP) + j]).arg(y[(i*numP) + j]));      pointX += dx;    }    pointY += dy;  }  // Do transformation. Any exception generated must  // be handled in above layers.  try  {    transformCoords( nXPoints * nYPoints, x.data(), y.data(), z.data(), direction );  }  catch ( const QgsCsException & )  {    // rethrow the exception    QgsDebugMsg( "rethrowing exception" );    throw;  }  // Calculate the bounding box and use that for the extent  for ( int i = 0; i < nXPoints * nYPoints; i++ )  {    if ( !qIsFinite( x[i] ) || !qIsFinite( y[i] ) )    {      continue;    }    if ( handle180Crossover )    {      //if crossing the date line, temporarily add 360 degrees to -ve longitudes      bb_rect.combineExtentWith( x[i] >= 0.0 ? x[i] : x[i] + 360.0, y[i] );    }    else    {      bb_rect.combineExtentWith( x[i], y[i] );    }  }  if ( handle180Crossover )  {    //subtract temporary addition of 360 degrees from longitudes    if ( bb_rect.xMinimum() > 180.0 )      bb_rect.setXMinimum( bb_rect.xMinimum() - 360.0 );//.........这里部分代码省略.........

    void init(unsigned w, unsigned h) {        ResourceMap resource;        resource.addPath("Fonts","");        std::string fontPath = resource.getPath("Fonts")+"monaco11";        font.load(fontPath.c_str());        console.reserve(height/font.lineHeight());        width=w;height=h;        objs.clear();        glMatrixMode (GL_PROJECTION);        glLoadIdentity ();        glFrustum (-1.0, 1.0, -1.0, 1.0, 1.5, 2000.0);                glEnable(GL_DEPTH_TEST);        glutIdleFunc (idle);        glutDisplayFunc (draw);        glutKeyboardFunc (keyboard);                       //adding here the mouse processing callbacks        glutMotionFunc(processMouseActiveMotion);        glutPassiveMotionFunc(processMousePassiveMotion);                GLfloat mat_specular[] = { .5, .5, .5, 1.0 };        GLfloat mat_shininess[] = { 5.0 };        GLfloat light_position[] = { 1.0, 1.0, 1.0, 0.0 };        glClearColor (0.0, 0.0, 0.0, 0.0);        glShadeModel (GL_SMOOTH);        glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);        glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);        glLightfv(GL_LIGHT0, GL_POSITION, light_position);                Color3 colors [] = {            Color3(255,0,0),            Color3(0,255,0),            Color3(0,0,255),            Color3(255,255,0),            Color3(0,255,255),            Color3(255,0,255),            Color3(255,255,255),        };                int n = 1;                for (unsigned i=0;i<n;i++) {             size_t size;//            size = objs.size();//            objs.push_back(Object());//            objs[size].p_ = DReal3(randnorm<dreal>(),randnorm<dreal>(),randnorm<dreal>());//            initModel(objs[objs.size()-1], icosa_vertex, icosa_indices,icosa_vertex_size,icosa_indices_size, colors[(i+5)%7],(7./n));            size = objs.size();            objs.push_back(Object());//            objs[size].p_ =0.8*DReal3(0.1+randnorm<dreal>(),0.1+randnorm<dreal>(),randnorm<dreal>());            //objs[size].p_ =0.5*DReal3(randnorm<dreal>(),randnorm<dreal>(),randnorm<dreal>());            objs[size].p_=Real3(0.5,0.,0.5)+0.1*Real3(randnorm<real>(),randnorm<real>(),randnorm<real>());            initModel(objs[objs.size()-1], bunny_vertex, bunny_indices,bunny_vertex_size,bunny_indices_size, colors[(i)%7],5/*(1./n)*/);            //            initModel(objs[objs.size()-1], bunnyh_vertex, bunnyh_indices,bunnyh_vertex_size,bunnyh_indices_size, colors[(i)%7],5/*(1./n)*/);        }        gettimeofday(&idleold, 0);                transformCoords();        buildTree(objs,coltrees);        colres.resize(coltrees.size());        for (unsigned i=0;i<coltrees.size();i++) {            coltrees[i]->collideWithSegment(seg[0], seg[1], colres[i]);        }    }

QgsRectangle QgsCoordinateTransform::transformBoundingBox( const QgsRectangle rect, TransformDirection direction ) const{  // Calculate the bounding box of a QgsRectangle in the source CRS  // when projected to the destination CRS (or the inverse).  // This is done by looking at a number of points spread evenly  // across the rectangle  if ( mShortCircuit || !mInitialisedFlag || rect.isEmpty() )    return rect;  static const int numP = 8;  QgsRectangle bb_rect;  bb_rect.setMinimal();  // We're interfacing with C-style vectors in the  // end, so let's do C-style vectors here too.  double x[numP * numP];  double y[numP * numP];  double z[numP * numP];  QgsDebugMsg( "Entering transformBoundingBox..." );  // Populate the vectors  double dx = rect.width()  / ( double )( numP - 1 );  double dy = rect.height() / ( double )( numP - 1 );  double pointY = rect.yMinimum();  for ( int i = 0; i < numP ; i++ )  {    // Start at right edge    double pointX = rect.xMinimum();    for ( int j = 0; j < numP; j++ )    {      x[( i*numP ) + j] = pointX;      y[( i*numP ) + j] = pointY;      // and the height...      z[( i*numP ) + j] = 0.0;      // QgsDebugMsg(QString("BBox coord: (%1, %2)").arg(x[(i*numP) + j]).arg(y[(i*numP) + j]));      pointX += dx;    }    pointY += dy;  }  // Do transformation. Any exception generated must  // be handled in above layers.  try  {    transformCoords( numP * numP, x, y, z, direction );  }  catch ( QgsCsException &cse )  {    // rethrow the exception    QgsDebugMsg( "rethrowing exception" );    throw cse;  }  // Calculate the bounding box and use that for the extent  for ( int i = 0; i < numP * numP; i++ )  {    if ( qIsFinite( x[i] ) && qIsFinite( y[i] ) )      bb_rect.combineExtentWith( x[i], y[i] );  }  QgsDebugMsg( "Projected extent: " + QString(( bb_rect.toString() ).toLocal8Bit().data() ) );  return bb_rect;}