forked from mthh/QgisDistanceCartogramPlugin
/
worker.py
197 lines (178 loc) · 7.57 KB
/
worker.py
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#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# /***************************************************************************
# DistanceCartogram
#
# Compute distance cartogram
# -------------------
# begin : 2018-07-13
# git sha : $Format:%H$
# copyright : (C) 2018 by Matthieu Viry
# email : matthieu.viry@cnrs.fr
# ***************************************************************************/
#
# /***************************************************************************
# * *
# * 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 math import sqrt
import traceback
from PyQt5.QtCore import (
pyqtSignal,
QObject,
QVariant
)
from qgis.core import (
QgsFeature,
QgsFeatureSink,
QgsGeometry,
QgsPointXY,
QgsVectorLayer,
QgsWkbTypes,
)
from .grid import Grid
class DistCartogramWorker(QObject):
resultComplete = pyqtSignal(object, object, object)
finished = pyqtSignal()
error = pyqtSignal(Exception, str)
progress = pyqtSignal(int)
status = pyqtSignal(str)
def __init__(self,
src_pts,
image_pts,
precision,
extent,
layers_to_transform,
to_display,
tr):
QObject.__init__(self)
self.src_pts = src_pts
self.image_pts = image_pts
self.precision = precision
self.extent = extent
self.layers_to_transform = layers_to_transform
self.to_display = to_display
self.tr = tr
def get_transformed_layers(self):
transformed_layers = []
for background_layer in self.layers_to_transform:
_t = QgsWkbTypes.displayString(background_layer.wkbType())
result_layer = QgsVectorLayer(
"{}?crs={}".format(_t, background_layer.crs().authid()),
"result_cartogram",
"memory")
features_to_add = []
result_layer.setCrs(background_layer.crs())
pr_result_layer = result_layer.dataProvider()
pr_result_layer.addAttributes(background_layer.fields().toList())
result_layer.updateFields()
for ix, ft in enumerate(background_layer.getFeatures()):
ref_geom = ft.geometry()
ref_coords = ref_geom.__geo_interface__['coordinates']
if ref_geom.__geo_interface__['type'] == 'LineString':
new_geom = QgsGeometry.fromPolyLineXY([
QgsPointXY(
*self.g._interp_point(*ref_coords[ix_coords]))
for ix_coords in range(len(ref_coords))
])
elif ref_geom.__geo_interface__['type'] == 'MultiLineString':
lines = []
for ix_line in range(len(ref_coords)):
lines.append([
QgsPointXY(
*self.g._interp_point(*ref_coords[ix_line][ix_coords]))
for ix_coords in range(len(ref_coords[ix_line]))
])
new_geom = QgsGeometry.fromMultiPolylineXY(lines)
elif ref_geom.__geo_interface__['type'] == 'Polygon':
rings = []
for ix_ring in range(len(ref_coords)):
rings.append([
QgsPointXY(
*self.g._interp_point(*ref_coords[ix_ring][ix_coords]))
for ix_coords in range(len(ref_coords[ix_ring]))
])
new_geom = QgsGeometry.fromPolygonXY(rings)
elif ref_geom.__geo_interface__['type'] == 'MultiPolygon':
polys = []
for ix_poly in range(len(ref_coords)):
rings = []
for ix_ring in range(len(ref_coords[ix_poly])):
rings.append([
QgsPointXY(
*self.g._interp_point(
*ref_coords[ix_poly][ix_ring][ix_coords]))
for ix_coords in range(len(ref_coords[ix_poly][ix_ring]))
])
polys.append(rings)
new_geom = QgsGeometry.fromMultiPolygonXY(polys)
else:
self.status.emit('Geometry type error')
continue
feature = QgsFeature()
feature.setGeometry(new_geom)
feature.setAttributes(ft.attributes())
features_to_add.append(feature)
self.progress.emit(1)
pr_result_layer.addFeatures(features_to_add)
result_layer.updateExtents()
transformed_layers.append(result_layer)
return transformed_layers
def run(self):
try:
_get_inter_nb_iter = \
lambda coef_iter: int(
coef_iter * sqrt(len(self.src_pts)))
self.status.emit(self.tr('Creation of interpolation grid...'))
self.g = Grid(self.src_pts, self.precision, self.extent)
self.status.emit(self.tr('Interpolation process...'))
self.progress.emit(((self.precision * len(self.image_pts)) / 3))
self.g.interpolate(self.image_pts, _get_inter_nb_iter(4))
self.progress.emit(((self.precision * len(self.image_pts)) / 3))
self.status.emit(self.tr('Transforming layers...'))
transformed_layers = self.get_transformed_layers()
self.status.emit(self.tr('Preparing results for displaying...'))
if self.to_display['source_grid']:
polys = self.g._get_grid_coords('source')
source_grid_layer = make_grid_layer(
polys, self.layers_to_transform[0].crs(), 'source')
else:
source_grid_layer = None
self.progress.emit(5)
if self.to_display['trans_grid']:
polys = self.g._get_grid_coords('interp')
trans_grid_layer = make_grid_layer(
polys, self.layers_to_transform[0].crs(), 'interp')
else:
trans_grid_layer = None
self.resultComplete.emit(
transformed_layers[0],
source_grid_layer,
trans_grid_layer,
)
self.finished.emit()
except Exception as e:
self.error.emit(e, traceback.format_exc())
def make_grid_layer(polys, crs, _type_grid):
result_layer = QgsVectorLayer(
"Polygon?crs={}&field=ID:integer".format(crs.authid()),
"{}_grid".format(_type_grid),
"memory")
result_layer.startEditing()
result_layer.setCrs(crs)
for ix, geom in enumerate(polys):
new_geom = QgsGeometry.fromPolygonXY([
[QgsPointXY(*geom[ix_ring][ix_coords])
for ix_coords in range(len(geom[ix_ring]))]
for ix_ring in range(len(geom))
])
feature = QgsFeature()
feature.setGeometry(new_geom)
feature.setAttributes([QVariant(ix)])
result_layer.addFeature(feature, QgsFeatureSink.FastInsert)
result_layer.commitChanges()
return result_layer