Supports linear referencing along a linear Geometry using LinearLocations as the index.
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#include <LocationIndexedLine.h>
Supports linear referencing along a linear Geometry using LinearLocations as the index.
◆ LocationIndexedLine()
| geos::linearref::LocationIndexedLine::LocationIndexedLine |
( |
const geom::Geometry * |
p_linearGeom | ) |
|
|
inline |
Constructs an object which allows linear referencing along a given linear Geometry.
- Parameters
-
| p_linearGeom | the linear geometry to reference along |
◆ clampIndex()
◆ extractLine()
Computes the LineString for the interval on the line between the given indices.
If the endIndex lies before the startIndex, the computed geometry is reversed.
- Parameters
-
| startIndex | the index of the start of the interval |
| endIndex | the index of the end of the interval |
- Returns
- the linear interval between the indices
References geos::linearref::ExtractLineByLocation::extract().
◆ extractPoint() [1/2]
Computes the Coordinate for the point on the line at the given index.
If the index is out of range the first or last point on the line will be returned. The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.
- Parameters
-
| index | the index of the desired point |
- Returns
- the Coordinate at the given index
References geos::linearref::LinearLocation::getCoordinate().
◆ extractPoint() [2/2]
Computes the Coordinate for the point on the line at the given index, offset by the given distance.
If the index is out of range the first or last point on the line will be returned. The computed point is offset to the left of the line if the offset distance is positive, to the right if negative.
The Z-ordinate of the computed point will be interpolated from the Z-ordinates of the line segment containing it, if they exist.
- Parameters
-
| index | the index of the desired point |
| offsetDistance | the distance the point is offset from the segment (positive is to the left, negative is to the right) |
- Returns
- the Coordinate at the given index
References geos::linearref::LinearLocation::getSegment(), and geos::linearref::LinearLocation::getSegmentFraction().
◆ getEndIndex()
| LinearLocation geos::linearref::LocationIndexedLine::getEndIndex |
( |
| ) |
const |
|
inline |
◆ getStartIndex()
| LinearLocation geos::linearref::LocationIndexedLine::getStartIndex |
( |
| ) |
const |
|
inline |
Returns the index of the start of the line.
- Returns
- the start index
◆ indexOf()
Computes the index for a given point on the line.
The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use project to compute a guaranteed result for points which may be far from the line.
- Parameters
-
- Returns
- the index of the point
- See also
- project
◆ indexOfAfter()
Finds the index for a point on the line which is greater than the given index.
If no such index exists, returns minIndex. This method can be used to determine all indexes for a point which occurs more than once on a non-simple line. It can also be used to disambiguate cases where the given point lies slightly off the line and is equidistant from two different points on the line.
The supplied point does not necessarily have to lie precisely on the line, but if it is far from the line the accuracy and performance of this function is not guaranteed. Use project to compute a guaranteed result for points which may be far from the line.
- Parameters
-
| pt | a point on the line |
| minIndex | the value the returned index must be greater than |
- Returns
- the index of the point greater than the given minimum index
- See also
- project
◆ indicesOf()
Computes the indices for a subline of the line.
(The subline must conform to the line; that is, all vertices in the subline (except possibly the first and last) must be vertices of the line and occur in the same order).
- Parameters
-
| subLine | a subLine of the line |
- Returns
- a pair of indices for the start and end of the subline.
References geos::linearref::LocationIndexOfLine::indicesOf().
◆ isValidIndex()
| bool geos::linearref::LocationIndexedLine::isValidIndex |
( |
const LinearLocation & |
index | ) |
const |
|
inline |
◆ project()
Computes the index for the closest point on the line to the given point.
If more than one point has the closest distance the first one along the line is returned. (The point does not necessarily have to lie precisely on the line.)
- Parameters
-
- Returns
- the index of the point
The documentation for this class was generated from the following file:
