QGIS/python/plugins/processing/algs/qgis/PointsDisplacement.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    PointsDisplacement.py
    ---------------------
    Date                 : July 2013
    Copyright            : (C) 2013 by Alexander Bruy
    Email                : alexander dot bruy at gmail dot com
***************************************************************************
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
***************************************************************************
"""
from builtins import next

__author__ = 'Alexander Bruy'
__date__ = 'July 2013'
__copyright__ = '(C) 2013, Alexander Bruy'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import math
from qgis.core import (QgsApplication,
                       QgsFeatureRequest,
                       QgsFeature,
                       QgsFeatureSink,
                       QgsGeometry,
                       QgsPointXY,
                       QgsProcessingUtils)
from processing.tools import dataobjects
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterNumber
from processing.core.parameters import ParameterBoolean
from processing.core.outputs import OutputVector


class PointsDisplacement(QgisAlgorithm):

    INPUT_LAYER = 'INPUT_LAYER'
    DISTANCE = 'DISTANCE'
    HORIZONTAL = 'HORIZONTAL'
    OUTPUT_LAYER = 'OUTPUT_LAYER'

    def group(self):
        return self.tr('Vector geometry tools')

    def __init__(self):
        super().__init__()
        self.addParameter(ParameterVector(self.INPUT_LAYER,
                                          self.tr('Input layer'), [dataobjects.TYPE_VECTOR_POINT]))
        self.addParameter(ParameterNumber(self.DISTANCE,
                                          self.tr('Displacement distance'),
                                          0.00001, 999999999.999990, 0.00015))
        self.addParameter(ParameterBoolean(self.HORIZONTAL,
                                           self.tr('Horizontal distribution for two point case')))
        self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Displaced'), datatype=[dataobjects.TYPE_VECTOR_POINT]))

    def name(self):
        return 'pointsdisplacement'

    def displayName(self):
        return self.tr('Points displacement')

    def processAlgorithm(self, parameters, context, feedback):
        radius = self.getParameterValue(self.DISTANCE)
        horizontal = self.getParameterValue(self.HORIZONTAL)
        output = self.getOutputFromName(self.OUTPUT_LAYER)

        layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)

        writer = output.getVectorWriter(layer.fields(), layer.wkbType(), layer.crs(), context)

        features = QgsProcessingUtils.getFeatures(layer, context)

        total = 100.0 / layer.featureCount() if layer.featureCount() else 0

        duplicates = dict()
        for current, f in enumerate(features):
            wkt = f.geometry().exportToWkt()
            if wkt not in duplicates:
                duplicates[wkt] = [f.id()]
            else:
                duplicates[wkt].extend([f.id()])

            feedback.setProgress(int(current * total))

        current = 0
        total = 100.0 / len(duplicates) if duplicates else 1
        feedback.setProgress(0)

        fullPerimeter = 2 * math.pi

        for (geom, fids) in list(duplicates.items()):
            count = len(fids)
            if count == 1:
                f = next(layer.getFeatures(QgsFeatureRequest().setFilterFid(fids[0])))
                writer.addFeature(f, QgsFeatureSink.FastInsert)
            else:
                angleStep = fullPerimeter / count
                if count == 2 and horizontal:
                    currentAngle = math.pi / 2
                else:
                    currentAngle = 0

                old_point = QgsGeometry.fromWkt(geom).asPoint()

                request = QgsFeatureRequest().setFilterFids(fids).setFlags(QgsFeatureRequest.NoGeometry)
                for f in layer.getFeatures(request):
                    sinusCurrentAngle = math.sin(currentAngle)
                    cosinusCurrentAngle = math.cos(currentAngle)
                    dx = radius * sinusCurrentAngle
                    dy = radius * cosinusCurrentAngle

                    new_point = QgsPointXY(old_point.x() + dx, old_point.y() + dy)
                    out_feature = QgsFeature()
                    out_feature.setGeometry(QgsGeometry.fromPoint(new_point))
                    out_feature.setAttributes(f.attributes())

                    writer.addFeature(out_feature, QgsFeatureSink.FastInsert)
                    currentAngle += angleStep

            current += 1
            feedback.setProgress(int(current * total))

        del writer