sharpetronics/QGIS
1
0
Fork 0
mirror of https://github.com/qgis/QGIS.git synced 2025-10-06 00:07:29 -04:00
Code Issues Packages Projects Releases Wiki Activity

[FEATURE] New expression functions for angle/distance interpolation

Browse Source 
angle_at_vertex: returns average (bisector) angle to a geometry
at a specified vertex index
distance_to_vertex: returns distance along geometry to a specified
vertex index
line_interpolate_angle: calculates the angle parallel to a geometry
at the specified distance along the geometry

Sponsored by Andreas Neumann
This commit is contained in:
Nyall Dawson 2016-08-25 18:36:28 +10:00
parent 9fa4e776db
commit da78ddeb7c
5 changed files with 67 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
resources/function_help/json/angle_at_vertex Normal file
View File

@ -0,0 +1,8 @@
{
"name": "angle_at_vertex",
"type": "function",
"description": "Returns the bisector angle (average angle) to the geometry for a specified vertex on a linestring geometry. Angles are in degrees clockwise from north.",
"arguments": [ {"arg":"geometry","description":"a linestring geometry"},
{"arg":"vertex","description":"vertex index, starting from 0"}],
"examples": [ { "expression":"angle_at_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)", "returns":"45.0"}]
}

8
resources/function_help/json/distance_to_vertex Normal file
View File

@ -0,0 +1,8 @@
{
"name": "distance_to_vertex",
"type": "function",
"description": "Returns the distance along the geometry to a specified vertex.",
"arguments": [ {"arg":"geometry","description":"a linestring geometry"},
{"arg":"vertex","description":"vertex index, starting from 0"}],
"examples": [ { "expression":"distance_to_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)", "returns":"10.0"}]
}

8
resources/function_help/json/line_interpolate_angle Normal file
View File

@ -0,0 +1,8 @@
{
"name": "line_interpolate_angle",
"type": "function",
"description": "Returns the angle parallel to the geometry at a specified distance along a linestring geometry. Angles are in degrees clockwise from north.",
"arguments": [ {"arg":"geometry","description":"a linestring geometry"},
{"arg":"distance","description":"distance along line to interpolate angle at"}],
"examples": [ { "expression":"line_interpolate_angle(geometry:=geom_from_wkt('LineString(0 0, 10 0)'),distance:=5)", "returns":"90.0"}]
}

31
src/core/qgsexpression.cpp
View File

@ -2559,6 +2559,30 @@ static QVariant fcnLineInterpolatePoint( const QVariantList& values, const QgsEx
return result;
}
static QVariant fcnLineInterpolateAngle( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
{
QgsGeometry lineGeom = getGeometry( values.at( 0 ), parent );
double distance = getDoubleValue( values.at( 1 ), parent );
return lineGeom.interpolateAngle( distance ) * 180.0 / M_PI;
}
static QVariant fcnAngleAtVertex( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
{
QgsGeometry geom = getGeometry( values.at( 0 ), parent );
int vertex = getIntValue( values.at( 1 ), parent );
return geom.angleAtVertex( vertex ) * 180.0 / M_PI;
}
static QVariant fcnDistanceToVertex( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
{
QgsGeometry geom = getGeometry( values.at( 0 ), parent );
int vertex = getIntValue( values.at( 1 ), parent );
return geom.distanceToVertex( vertex );
}
static QVariant fcnLineLocatePoint( const QVariantList& values, const QgsExpressionContext*, QgsExpression* parent )
{
QgsGeometry lineGeom = getGeometry( values.at( 0 ), parent );
@ -3148,6 +3172,7 @@ const QStringList& QgsExpression::BuiltinFunctions()
<< "distance" << "intersection" << "sym_difference" << "combine"
<< "extrude" << "azimuth" << "project" << "closest_point" << "shortest_line"
<< "line_locate_point" << "line_interpolate_point"
<< "line_interpolate_angle" << "angle_at_vertex" << "distance_to_vertex"
<< "union" << "geom_to_wkt" << "geomToWKT" << "geometry"
<< "transform" << "get_feature" << "getFeature"
<< "levenshtein" << "longest_common_substring" << "hamming_distance"
@ -3375,8 +3400,14 @@ const QList<QgsExpression::Function*>& QgsExpression::Functions()
<< new StaticFunction( "shortest_line", 2, fcnShortestLine, "GeometryGroup" )
<< new StaticFunction( "line_interpolate_point", ParameterList() << Parameter( "geometry" )
<< Parameter( "distance" ), fcnLineInterpolatePoint, "GeometryGroup" )
<< new StaticFunction( "line_interpolate_angle", ParameterList() << Parameter( "geometry" )
<< Parameter( "distance" ), fcnLineInterpolateAngle, "GeometryGroup" )
<< new StaticFunction( "line_locate_point", ParameterList() << Parameter( "geometry" )
<< Parameter( "point" ), fcnLineLocatePoint, "GeometryGroup" )
<< new StaticFunction( "angle_at_vertex", ParameterList() << Parameter( "geometry" )
<< Parameter( "vertex" ), fcnAngleAtVertex, "GeometryGroup" )
<< new StaticFunction( "distance_to_vertex", ParameterList() << Parameter( "geometry" )
<< Parameter( "vertex" ), fcnDistanceToVertex, "GeometryGroup" )
<< new StaticFunction( "$id", 0, fcnFeatureId, "Record" )
<< new StaticFunction( "$currentfeature", 0, fcnFeature, "Record" )
<< new StaticFunction( "uuid", 0, fcnUuid, "Record", QString(), false, QStringList(), false, QStringList() << "$uuid" )

12
tests/src/core/testqgsexpression.cpp
View File

@ -786,6 +786,18 @@ class TestQgsExpression: public QObject
QTest::newRow( "line_locate_point null" ) << "line_locate_point(NULL, geom_from_wkt('Point 5 0'))" << false << QVariant();
QTest::newRow( "line_locate_point point" ) << "line_locate_point(geom_from_wkt('POINT(1 2)'),geom_from_wkt('Point 5 0'))" << false << QVariant();
QTest::newRow( "line_locate_point line" ) << "line_locate_point(geometry:=geom_from_wkt('LineString(0 0, 10 0)'),point:=geom_from_wkt('Point(5 0)'))" << false << QVariant( 5.0 );
QTest::newRow( "line_interpolate_angle not geom" ) << "line_interpolate_angle('g', 5)" << true << QVariant();
QTest::newRow( "line_interpolate_angle null" ) << "line_interpolate_angle(NULL, 5)" << false << QVariant();
QTest::newRow( "line_interpolate_angle point" ) << "line_interpolate_angle(geom_from_wkt('POINT(1 2)'),5)" << false << QVariant( 0.0 );
QTest::newRow( "line_interpolate_angle line" ) << "line_interpolate_angle(geometry:=geom_from_wkt('LineString(0 0, 10 0)'),distance:=5)" << false << QVariant( 90.0 );
QTest::newRow( "angle_at_vertex not geom" ) << "angle_at_vertex('g', 5)" << true << QVariant();
QTest::newRow( "angle_at_vertex null" ) << "angle_at_vertex(NULL, 0)" << false << QVariant();
QTest::newRow( "angle_at_vertex point" ) << "angle_at_vertex(geom_from_wkt('POINT(1 2)'),0)" << false << QVariant( 0.0 );
QTest::newRow( "angle_at_vertex line" ) << "angle_at_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)" << false << QVariant( 45.0 );
QTest::newRow( "distance_to_vertex not geom" ) << "distance_to_vertex('g', 5)" << true << QVariant();
QTest::newRow( "distance_to_vertex null" ) << "distance_to_vertex(NULL, 0)" << false << QVariant();
QTest::newRow( "distance_to_vertex point" ) << "distance_to_vertex(geom_from_wkt('POINT(1 2)'),0)" << false << QVariant( 0.0 );
QTest::newRow( "distance_to_vertex line" ) << "distance_to_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)" << false << QVariant( 10.0 );
// string functions
QTest::newRow( "lower" ) << "lower('HeLLo')" << false << QVariant( "hello" );