Class: QgsAbstractGeometryTransformer

An abstract base class for classes which transform geometries by transforming input points to output points.

Added in version 3.18.

Class Hierarchy

Inheritance diagram of qgis.core.QgsAbstractGeometryTransformer

Subclasses

QgsGcpGeometryTransformer

A geometry transformer which uses an underlying Ground Control Points (GCP) based transformation to modify geometries.

Methods

transformPoint

Transforms the point defined by the coordinates (x, y, z) and the specified m value.
class qgis.core.QgsAbstractGeometryTransformer[source]

Bases: object

transformPoint(self, x: float, y: float, z: float, m: float)[source]

Transforms the point defined by the coordinates (x, y, z) and the specified m value.

Parameters:

  • x (float) – point x coordinate

  • y (float) – point y coordinate

  • z (float) – point z coordinate, or NaN if the input point is 2D only

  • m (float) -> (bool) – point m value, or NaN if not available

Returns:

True if point was transformed (or no transformation was required), or False if point could not be transformed successfully.

Example

A transformer which multiples the x coordinate by 3 and adds 10 to the y coordinate:

class MyTransformer(QgsAbstractGeometryTransformer):

  def transformPoint(self, x, y, z, m):
    # returns a tuple of True to indicate success, then the modified x/y/z/m values
    return True, x*3, y+10, z, m