QgsGeometry QgsMapToolDeleteRing::ringUnderPoint( const QgsPoint &p, QgsFeatureId &fid, int &partNum, int &ringNum )
{
//There is no clean way to find if we are inside the ring of a feature,
//so we iterate over all the features visible in the canvas
//If several rings are found at this position, the smallest one is chosen,
//in order to be able to delete a ring inside another ring
QgsFeatureIterator fit = vlayer->getFeatures( QgsFeatureRequest().setFilterRect( toLayerCoordinates( vlayer, mCanvas->extent() ) ) );
QgsFeature f;
QgsGeometry g;
QgsGeometry ringGeom;
QgsMultiPolygon pol;
QgsPolygon tempPol;
QgsGeometry tempGeom;
double area = std::numeric_limits<double>::max();
while ( fit.nextFeature( f ) )
{
g = f.geometry();
if ( g.isNull() )
continue;
if ( g.wkbType() == QgsWkbTypes::Polygon || g.wkbType() == QgsWkbTypes::Polygon25D )
{
pol = QgsMultiPolygon() << g.asPolygon();
}
else
{
pol = g.asMultiPolygon();
}
for ( int i = 0; i < pol.size() ; ++i )
{
//for each part
if ( pol[i].size() > 1 )
{
for ( int j = 1; j < pol[i].size(); ++j )
{
tempPol = QgsPolygon() << pol[i][j];
tempGeom = QgsGeometry::fromPolygon( tempPol );
if ( tempGeom.area() < area && tempGeom.contains( &p ) )
{
fid = f.id();
partNum = i;
ringNum = j;
area = tempGeom.area();
ringGeom = tempGeom;
}
}
}
}
}
return ringGeom;
}
void QgsZonalStatistics::statisticsFromPreciseIntersection( const QgsGeometry &poly, int pixelOffsetX,
int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle &rasterBBox, FeatureStats &stats )
{
stats.reset();
double currentY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
QgsGeometry pixelRectGeometry;
double hCellSizeX = cellSizeX / 2.0;
double hCellSizeY = cellSizeY / 2.0;
double pixelArea = cellSizeX * cellSizeY;
double weight = 0;
QgsRectangle featureBBox = poly.boundingBox().intersect( &rasterBBox );
QgsRectangle intersectBBox = rasterBBox.intersect( &featureBBox );
QgsRasterBlock *block = mRasterProvider->block( mRasterBand, intersectBBox, nCellsX, nCellsY );
for ( int i = 0; i < nCellsY; ++i )
{
double currentX = rasterBBox.xMinimum() + cellSizeX / 2.0 + pixelOffsetX * cellSizeX;
for ( int j = 0; j < nCellsX; ++j )
{
if ( !validPixel( block->value( i, j ) ) )
{
continue;
}
pixelRectGeometry = QgsGeometry::fromRect( QgsRectangle( currentX - hCellSizeX, currentY - hCellSizeY, currentX + hCellSizeX, currentY + hCellSizeY ) );
if ( !pixelRectGeometry.isNull() )
{
//intersection
QgsGeometry intersectGeometry = pixelRectGeometry.intersection( poly );
if ( !intersectGeometry.isNull() )
{
double intersectionArea = intersectGeometry.area();
if ( intersectionArea >= 0.0 )
{
weight = intersectionArea / pixelArea;
stats.addValue( block->value( i, j ), weight );
}
}
pixelRectGeometry = QgsGeometry();
}
currentX += cellSizeX;
}
currentY -= cellSizeY;
}
delete block;
}
void QgsZonalStatistics::statisticsFromPreciseIntersection( void* band, const QgsGeometry* poly, int pixelOffsetX,
int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle& rasterBBox, FeatureStats &stats )
{
stats.reset();
double currentY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
float* pixelData = ( float * ) CPLMalloc( sizeof( float ) );
QgsGeometry* pixelRectGeometry = nullptr;
double hCellSizeX = cellSizeX / 2.0;
double hCellSizeY = cellSizeY / 2.0;
double pixelArea = cellSizeX * cellSizeY;
double weight = 0;
for ( int row = 0; row < nCellsY; ++row )
{
double currentX = rasterBBox.xMinimum() + cellSizeX / 2.0 + pixelOffsetX * cellSizeX;
for ( int col = 0; col < nCellsX; ++col )
{
if ( GDALRasterIO( band, GF_Read, pixelOffsetX + col, pixelOffsetY + row, nCellsX, 1, pixelData, 1, 1, GDT_Float32, 0, 0 ) != CE_None )
QgsDebugMsg( "Raster IO Error" );
if ( !validPixel( *pixelData ) )
continue;
pixelRectGeometry = QgsGeometry::fromRect( QgsRectangle( currentX - hCellSizeX, currentY - hCellSizeY, currentX + hCellSizeX, currentY + hCellSizeY ) );
if ( pixelRectGeometry )
{
//intersection
QgsGeometry *intersectGeometry = pixelRectGeometry->intersection( poly );
if ( intersectGeometry )
{
double intersectionArea = intersectGeometry->area();
if ( intersectionArea >= 0.0 )
{
weight = intersectionArea / pixelArea;
stats.addValue( *pixelData, weight );
}
delete intersectGeometry;
}
delete pixelRectGeometry;
pixelRectGeometry = nullptr;
}
currentX += cellSizeX;
}
currentY -= cellSizeY;
}
CPLFree( pixelData );
}
void QgsZonalStatistics::statisticsFromPreciseIntersection( void* band, QgsGeometry* poly, int pixelOffsetX,
int pixelOffsetY, int nCellsX, int nCellsY, double cellSizeX, double cellSizeY, const QgsRectangle& rasterBBox, double& sum, double& count )
{
sum = 0;
count = 0;
double currentY = rasterBBox.yMaximum() - pixelOffsetY * cellSizeY - cellSizeY / 2;
float* pixelData = ( float * ) CPLMalloc( sizeof( float ) );
QgsGeometry* pixelRectGeometry = 0;
double hCellSizeX = cellSizeX / 2.0;
double hCellSizeY = cellSizeY / 2.0;
double pixelArea = cellSizeX * cellSizeY;
double weight = 0;
for ( int row = 0; row < nCellsY; ++row )
{
double currentX = rasterBBox.xMinimum() + cellSizeX / 2.0 + pixelOffsetX * cellSizeX;
for ( int col = 0; col < nCellsX; ++col )
{
GDALRasterIO( band, GF_Read, pixelOffsetX + col, pixelOffsetY + row, nCellsX, 1, pixelData, 1, 1, GDT_Float32, 0, 0 );
pixelRectGeometry = QgsGeometry::fromRect( QgsRectangle( currentX - hCellSizeX, currentY - hCellSizeY, currentX + hCellSizeX, currentY + hCellSizeY ) );
if ( pixelRectGeometry )
{
//intersection
QgsGeometry *intersectGeometry = pixelRectGeometry->intersection( poly );
if ( intersectGeometry )
{
double intersectionArea = intersectGeometry->area();
if ( intersectionArea >= 0.0 )
{
weight = intersectionArea / pixelArea;
count += weight;
sum += *pixelData * weight;
}
delete intersectGeometry;
}
delete pixelRectGeometry;
pixelRectGeometry = 0;
}
currentX += cellSizeX;
}
currentY -= cellSizeY;
}
CPLFree( pixelData );
}