QGIS/python/plugins/processing/algs/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.                                   *
*                                                                         *
***************************************************************************
"""

__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 PyQt4.QtCore import *
from qgis.core import *
from processing.tools import dataobjects, vector
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterNumber import ParameterNumber
from processing.parameters.ParameterBoolean import ParameterBoolean
from processing.outputs.OutputVector import OutputVector

class PointsDisplacement(GeoAlgorithm):

    INPUT_LAYER = "INPUT_LAYER"
    DISTANCE = "DISTANCE"
    HORIZONTAL = "HORIZONTAL"
    OUTPUT_LAYER = "OUTPUT_LAYER"

    def defineCharacteristics(self):
        self.name = "Points displacement"
        self.group = "Vector geometry tools"

        self.addParameter(ParameterVector(self.INPUT_LAYER, "Input layer", [ParameterVector.VECTOR_TYPE_POINT]))
        self.addParameter(ParameterNumber(self.DISTANCE, "Displacement distance", 0.00001, 999999999.999990, 0.00015))
        self.addParameter(ParameterBoolean(self.HORIZONTAL, "Horizontal distribution for two point case"))
        self.addOutput(OutputVector(self.OUTPUT_LAYER, "Output layer"))

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

        layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))

        provider = layer.dataProvider()
        writer = output.getVectorWriter(provider.fields(), provider.geometryType(), provider.crs())

        features = vector.features(layer)

        current = 0
        total = 100.0 / len(features)

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

            current += 1
            progress.setPercentage(int(current * total))

        current = 0
        total = 100.0 / len(duplicates)
        progress.setPercentage(0)

        fullPerimeter = 2 * math.pi

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

                old_point = QgsGeometry.fromWkt(geom).asPoint()
                for fid in fids:
                    sinusCurrentAngle = math.sin(currentAngle)
                    cosinusCurrentAngle = math.cos(currentAngle)
                    dx = radius * sinusCurrentAngle
                    dy = radius * cosinusCurrentAngle

                    f = layer.getFeatures(request.setFilterFid(fid)).next()

                    new_point = QgsPoint(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)
                    currentAngle += angleStep

            current += 1
            progress.setPercentage(int(current * total))

        del writer