本文整理汇总了C++中QgsMultiPolyline::begin方法的典型用法代码示例。如果您正苦于以下问题：C++ QgsMultiPolyline::begin方法的具体用法？C++ QgsMultiPolyline::begin怎么用？C++ QgsMultiPolyline::begin使用的例子？那么, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类QgsMultiPolyline的用法示例。
在下文中一共展示了QgsMultiPolyline::begin方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的C++代码示例。
示例1: makeGraph
void QgsLineVectorLayerDirector::makeGraph( QgsGraphBuilderInterface *builder, const QVector< QgsPoint >& additionalPoints,
QVector< QgsPoint >& tiedPoint ) const
{
QgsVectorLayer *vl = mVectorLayer;
if ( vl == NULL )
return;
int featureCount = ( int ) vl->featureCount() * 2;
int step = 0;
QgsCoordinateTransform ct;
ct.setSourceCrs( vl->crs() );
if ( builder->coordinateTransformationEnabled() )
{
ct.setDestCRS( builder->destinationCrs() );
}
else
{
ct.setDestCRS( vl->crs() );
}
tiedPoint = QVector< QgsPoint >( additionalPoints.size(), QgsPoint( 0.0, 0.0 ) );
TiePointInfo tmpInfo;
tmpInfo.mLength = std::numeric_limits<double>::infinity();
QVector< TiePointInfo > pointLengthMap( additionalPoints.size(), tmpInfo );
QVector< TiePointInfo >::iterator pointLengthIt;
//Graph's points;
QVector< QgsPoint > points;
QgsFeatureIterator fit = vl->getFeatures( QgsFeatureRequest().setSubsetOfAttributes( QgsAttributeList() ) );
// begin: tie points to the graph
QgsAttributeList la;
QgsFeature feature;
while ( fit.nextFeature( feature ) )
{
QgsMultiPolyline mpl;
if ( feature.constGeometry()->wkbType() == QGis::WKBMultiLineString )
mpl = feature.constGeometry()->asMultiPolyline();
else if ( feature.constGeometry()->wkbType() == QGis::WKBLineString )
mpl.push_back( feature.constGeometry()->asPolyline() );
QgsMultiPolyline::iterator mplIt;
for ( mplIt = mpl.begin(); mplIt != mpl.end(); ++mplIt )
{
QgsPoint pt1, pt2;
bool isFirstPoint = true;
QgsPolyline::iterator pointIt;
for ( pointIt = mplIt->begin(); pointIt != mplIt->end(); ++pointIt )
{
pt2 = ct.transform( *pointIt );
points.push_back( pt2 );
if ( !isFirstPoint )
{
int i = 0;
for ( i = 0; i != additionalPoints.size(); ++i )
{
TiePointInfo info;
if ( pt1 == pt2 )
{
info.mLength = additionalPoints[ i ].sqrDist( pt1 );
info.mTiedPoint = pt1;
}
else
{
info.mLength = additionalPoints[ i ].sqrDistToSegment( pt1.x(), pt1.y(),
pt2.x(), pt2.y(), info.mTiedPoint );
}
if ( pointLengthMap[ i ].mLength > info.mLength )
{
Q_UNUSED( info.mTiedPoint );
info.mFirstPoint = pt1;
info.mLastPoint = pt2;
pointLengthMap[ i ] = info;
tiedPoint[ i ] = info.mTiedPoint;
}
}
}
pt1 = pt2;
isFirstPoint = false;
}
}
emit buildProgress( ++step, featureCount );
}
// end: tie points to graph
// add tied point to graph
int i = 0;
for ( i = 0; i < tiedPoint.size(); ++i )
{
if ( tiedPoint[ i ] != QgsPoint( 0.0, 0.0 ) )
{
points.push_back( tiedPoint [ i ] );
//.........这里部分代码省略.........
示例2: makeGraph
void RgLineVectorLayerDirector::makeGraph( RgGraphBuilder *builder, const QVector< QgsPoint >& additionalPoints,
QVector< QgsPoint >& tiedPoint ) const
{
QgsVectorLayer *vl = myLayer();
if ( vl == NULL )
return;
int featureCount = ( int ) vl->featureCount() * 2;
int step = 0;
QgsCoordinateTransform ct;
QgsDistanceArea da;
ct.setSourceCrs( vl->crs() );
if ( builder->coordinateTransformEnabled() )
{
ct.setDestCRS( builder->destinationCrs() );
da.setProjectionsEnabled( true );
//
//da.setSourceCrs( builder->destinationCrs().srsid() );
//
}
else
{
ct.setDestCRS( vl->crs() );
da.setProjectionsEnabled( false );
}
tiedPoint = QVector< QgsPoint >( additionalPoints.size(), QgsPoint( 0.0, 0.0 ) );
TiePointInfo tmpInfo;
tmpInfo.mLength = infinity();
QVector< TiePointInfo > pointLengthMap( additionalPoints.size(), tmpInfo );
QVector< TiePointInfo >::iterator pointLengthIt;
// begin: tie points to the graph
QgsAttributeList la;
vl->select( la );
QgsFeature feature;
while ( vl->nextFeature( feature ) )
{
QgsMultiPolyline mpl;
if ( feature.geometry()->wkbType() == QGis::WKBLineString )
{
mpl.push_back( feature.geometry()->asPolyline() );
}else if ( feature.geometry()->wkbType() == QGis::WKBMultiLineString )
{
mpl = feature.geometry()->asMultiPolyline();
}
QgsMultiPolyline::iterator mplIt;
for ( mplIt = mpl.begin(); mplIt != mpl.end(); ++mplIt )
{
QgsPoint pt1, pt2;
bool isFirstPoint = true;
QgsPolyline::iterator pointIt;
for ( pointIt = mplIt->begin(); pointIt != mplIt->end(); ++pointIt )
{
pt2 = builder->addVertex( ct.transform( *pointIt ) );
if ( !isFirstPoint )
{
int i = 0;
for ( i = 0; i != additionalPoints.size(); ++i )
{
TiePointInfo info;
if ( pt1 == pt2 )
{
info.mLength = additionalPoints[ i ].sqrDist( pt1 );
info.mTiedPoint = pt1;
}
else
{
info.mLength = additionalPoints[ i ].sqrDistToSegment( pt1.x(), pt1.y(), pt2.x(), pt2.y(), info.mTiedPoint );
}
if ( pointLengthMap[ i ].mLength > info.mLength )
{
info.mTiedPoint = builder->addVertex( info.mTiedPoint );
info.mFirstPoint = pt1;
info.mLastPoint = pt2;
pointLengthMap[ i ] = info;
tiedPoint[ i ] = info.mTiedPoint;
}
}
}
pt1 = pt2;
isFirstPoint = false;
}
}
emit buildProgress( ++step, featureCount );
}
// end: tie points to graph
if ( mDirectionFieldId != -1 )
{
la.push_back( mDirectionFieldId );
}
if ( mSpeedFieldId != -1 )
{
//.........这里部分代码省略.........