double QgsDistanceArea::measurePerimeter( const QgsGeometry* geometry ) const
{
if ( !geometry )
return 0.0;
const QgsAbstractGeometryV2* geomV2 = geometry->geometry();
if ( !geomV2 || geomV2->dimension() < 2 )
{
return 0.0;
}
if ( !mEllipsoidalMode || mEllipsoid == GEO_NONE )
{
return geomV2->perimeter();
}
//create list with (single) surfaces
QList< const QgsSurfaceV2* > surfaces;
const QgsSurfaceV2* surf = dynamic_cast<const QgsSurfaceV2*>( geomV2 );
if ( surf )
{
surfaces.append( surf );
}
const QgsMultiSurfaceV2* multiSurf = dynamic_cast<const QgsMultiSurfaceV2*>( geomV2 );
if ( multiSurf )
{
surfaces.reserve(( surf ? 1 : 0 ) + multiSurf->numGeometries() );
for ( int i = 0; i < multiSurf->numGeometries(); ++i )
{
surfaces.append( static_cast<const QgsSurfaceV2*>( multiSurf->geometryN( i ) ) );
}
}
double length = 0;
QList<const QgsSurfaceV2*>::const_iterator surfaceIt = surfaces.constBegin();
for ( ; surfaceIt != surfaces.constEnd(); ++surfaceIt )
{
if ( !*surfaceIt )
{
continue;
}
QgsPolygonV2* poly = ( *surfaceIt )->surfaceToPolygon();
const QgsCurveV2* outerRing = poly->exteriorRing();
if ( outerRing )
{
length += measure( outerRing );
}
int nInnerRings = poly->numInteriorRings();
for ( int i = 0; i < nInnerRings; ++i )
{
length += measure( poly->interiorRing( i ) );
}
delete poly;
}
return length;
}
// Make sure all rings are closed and have > 3 points.
static bool lwpoly_make_geos_friendly( QgsPolygonV2 &poly )
{
// If the polygon has no rings there's nothing to do
// TODO: in qgis representation there always is exterior ring
//if ( ! poly->nrings ) return true;
// All rings must be closed and have > 3 points
for ( int i = 0; i < poly.numInteriorRings(); i++ )
{
if ( !ring_make_geos_friendly( *const_cast<QgsCurve *>( poly.interiorRing( i ) ) ) )
return false;
}
return true;
}
QString QgsMultiSurface::asJSON( int precision ) const
{
// GeoJSON does not support curves
QString json = QStringLiteral( "{\"type\": \"MultiPolygon\", \"coordinates\": [" );
Q_FOREACH ( const QgsAbstractGeometry *geom, mGeometries )
{
if ( dynamic_cast<const QgsSurface*>( geom ) )
{
json += '[';
QgsPolygonV2* polygon = static_cast<const QgsSurface*>( geom )->surfaceToPolygon();
QgsLineString* exteriorLineString = polygon->exteriorRing()->curveToLine();
QgsPointSequence exteriorPts;
exteriorLineString->points( exteriorPts );
json += QgsGeometryUtils::pointsToJSON( exteriorPts, precision ) + ", ";
delete exteriorLineString;
for ( int i = 0, n = polygon->numInteriorRings(); i < n; ++i )
{
QgsLineString* interiorLineString = polygon->interiorRing( i )->curveToLine();
QgsPointSequence interiorPts;
interiorLineString->points( interiorPts );
json += QgsGeometryUtils::pointsToJSON( interiorPts, precision ) + ", ";
delete interiorLineString;
}
if ( json.endsWith( QLatin1String( ", " ) ) )
{
json.chop( 2 ); // Remove last ", "
}
delete polygon;
json += QLatin1String( "], " );
}
}
if ( json.endsWith( QLatin1String( ", " ) ) )
{
json.chop( 2 ); // Remove last ", "
}
json += QLatin1String( "] }" );
return json;
}
double QgsDistanceArea::measure( const QgsAbstractGeometryV2* geomV2, MeasureType type ) const
{
if ( !geomV2 )
{
return 0.0;
}
int geomDimension = geomV2->dimension();
if ( geomDimension <= 0 )
{
return 0.0;
}
MeasureType measureType = type;
if ( measureType == Default )
{
measureType = ( geomDimension == 1 ? Length : Area );
}
if ( !mEllipsoidalMode || mEllipsoid == GEO_NONE )
{
//no transform required
if ( measureType == Length )
{
return geomV2->length();
}
else
{
return geomV2->area();
}
}
else
{
//multigeom is sum of measured parts
const QgsGeometryCollectionV2* collection = dynamic_cast<const QgsGeometryCollectionV2*>( geomV2 );
if ( collection )
{
double sum = 0;
for ( int i = 0; i < collection->numGeometries(); ++i )
{
sum += measure( collection->geometryN( i ), measureType );
}
return sum;
}
if ( measureType == Length )
{
const QgsCurveV2* curve = dynamic_cast<const QgsCurveV2*>( geomV2 );
if ( !curve )
{
return 0.0;
}
QgsLineStringV2* lineString = curve->curveToLine();
double length = measureLine( lineString );
delete lineString;
return length;
}
else
{
const QgsSurfaceV2* surface = dynamic_cast<const QgsSurfaceV2*>( geomV2 );
if ( !surface )
return 0.0;
QgsPolygonV2* polygon = surface->surfaceToPolygon();
double area = 0;
const QgsCurveV2* outerRing = polygon->exteriorRing();
area += measurePolygon( outerRing );
for ( int i = 0; i < polygon->numInteriorRings(); ++i )
{
const QgsCurveV2* innerRing = polygon->interiorRing( i );
area -= measurePolygon( innerRing );
}
delete polygon;
return area;
}
}
}