# -*- coding: utf-8 -*-
"""
***************************************************************************
GridPolygon.py
---------------------
Date : May 2010
Copyright : (C) 2010 by Michael Minn
Email : pyqgis at michaelminn 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__ = 'Michael Minn'
__date__ = 'May 2010'
__copyright__ = '(C) 2010, Michael Minn'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
import math
from qgis.PyQt.QtGui import QIcon
from qgis.PyQt.QtCore import QVariant
from qgis.core import QgsRectangle, QgsCoordinateReferenceSystem, Qgis, QgsField, QgsFeature, QgsGeometry, QgsPoint, QgsWkbTypes
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterExtent
from processing.core.parameters import ParameterNumber
from processing.core.parameters import ParameterSelection
from processing.core.parameters import ParameterCrs
from processing.core.outputs import OutputVector
from processing.tools import dataobjects
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class GridPolygon(GeoAlgorithm):
TYPE = 'TYPE'
EXTENT = 'EXTENT'
HSPACING = 'HSPACING'
VSPACING = 'VSPACING'
CRS = 'CRS'
OUTPUT = 'OUTPUT'
def getIcon(self):
return QIcon(os.path.join(pluginPath, 'images', 'ftools', 'vector_grid.png'))
def defineCharacteristics(self):
self.name, self.i18n_name = self.trAlgorithm('Create grid (polygon)')
self.group, self.i18n_group = self.trAlgorithm('Vector creation tools')
self.tags = self.tr('grid,polygons,vector,create,fishnet')
self.types = [self.tr('Rectangle (polygon)'),
self.tr('Diamond (polygon)'),
self.tr('Hexagon (polygon)')]
self.addParameter(ParameterSelection(self.TYPE,
self.tr('Grid type'), self.types))
self.addParameter(ParameterExtent(self.EXTENT,
self.tr('Grid extent'), optional=False))
self.addParameter(ParameterNumber(self.HSPACING,
self.tr('Horizontal spacing'), 0.0, 1000000000.0, 0.0001))
self.addParameter(ParameterNumber(self.VSPACING,
self.tr('Vertical spacing'), 0.0, 1000000000.0, 0.0001))
self.addParameter(ParameterCrs(self.CRS, 'Grid CRS', 'EPSG:4326'))
self.addOutput(OutputVector(self.OUTPUT, self.tr('Grid'), datatype=[dataobjects.TYPE_VECTOR_POLYGON]))
def processAlgorithm(self, progress):
idx = self.getParameterValue(self.TYPE)
extent = self.getParameterValue(self.EXTENT).split(',')
hSpacing = self.getParameterValue(self.HSPACING)
vSpacing = self.getParameterValue(self.VSPACING)
crs = QgsCoordinateReferenceSystem(self.getParameterValue(self.CRS))
bbox = QgsRectangle(float(extent[0]), float(extent[2]),
float(extent[1]), float(extent[3]))
width = bbox.width()
height = bbox.height()
originX = bbox.xMinimum()
originY = bbox.yMaximum()
if hSpacing <= 0 or vSpacing <= 0:
raise GeoAlgorithmExecutionException(
self.tr('Invalid grid spacing: %s/%s' % (hSpacing, vSpacing)))
if width < hSpacing:
raise GeoAlgorithmExecutionException(
self.tr('Horizontal spacing is too small for the covered area'))
if height < vSpacing:
raise GeoAlgorithmExecutionException(
self.tr('Vertical spacing is too small for the covered area'))
fields = [QgsField('left', QVariant.Double, '', 24, 16),
QgsField('top', QVariant.Double, '', 24, 16),
QgsField('right', QVariant.Double, '', 24, 16),
QgsField('bottom', QVariant.Double, '', 24, 16),
QgsField('id', QVariant.Int, '', 10, 0)
]
writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(fields,
QgsWkbTypes.Polygon, crs)
if idx == 0:
self._rectangleGrid(
writer, width, height, originX, originY, hSpacing, vSpacing, progress)
elif idx == 1:
self._diamondGrid(
writer, width, height, originX, originY, hSpacing, vSpacing, progress)
elif idx == 2:
self._hexagonGrid(
writer, width, height, originX, originY, hSpacing, vSpacing, progress)
del writer
def _rectangleGrid(self, writer, width, height, originX, originY,
hSpacing, vSpacing, progress):
ft = QgsFeature()
columns = int(math.ceil(float(width) / hSpacing))
rows = int(math.ceil(float(height) / vSpacing))
cells = rows * columns
count_update = cells * 0.05
id = 1
count = 0
for col in range(columns):
# (column + 1) and (row + 1) calculation is used to maintain
# topology between adjacent shapes and avoid overlaps/holes
# due to rounding errors
x1 = originX + (col * hSpacing)
x2 = originX + ((col + 1) * hSpacing)
for row in range(rows):
y1 = originY - (row * vSpacing)
y2 = originY - ((row + 1) * vSpacing)
polyline = []
polyline.append(QgsPoint(x1, y1))
polyline.append(QgsPoint(x2, y1))
polyline.append(QgsPoint(x2, y2))
polyline.append(QgsPoint(x1, y2))
polyline.append(QgsPoint(x1, y1))
ft.setGeometry(QgsGeometry.fromPolygon([polyline]))
ft.setAttributes([x1, y1, x2, y2, id])
writer.addFeature(ft)
id += 1
count += 1
if int(math.fmod(count, count_update)) == 0:
progress.setPercentage(int(count / cells * 100))
def _diamondGrid(self, writer, width, height, originX, originY,
hSpacing, vSpacing, progress):
ft = QgsFeature()
halfHSpacing = hSpacing / 2
halfVSpacing = vSpacing / 2
columns = int(math.ceil(float(width) / halfHSpacing))
rows = int(math.ceil(float(height) / vSpacing))
cells = rows * columns
count_update = cells * 0.05
id = 1
count = 0
for col in range(columns):
x1 = originX + ((col + 0) * halfHSpacing)
x2 = originX + ((col + 1) * halfHSpacing)
x3 = originX + ((col + 2) * halfHSpacing)
for row in range(rows):
if (col % 2) == 0:
y1 = originY - (((row * 2) + 0) * halfVSpacing)
y2 = originY - (((row * 2) + 1) * halfVSpacing)
y3 = originY - (((row * 2) + 2) * halfVSpacing)
else:
y1 = originY - (((row * 2) + 1) * halfVSpacing)
y2 = originY - (((row * 2) + 2) * halfVSpacing)
y3 = originY - (((row * 2) + 3) * halfVSpacing)
polyline = []
polyline.append(QgsPoint(x1, y2))
polyline.append(QgsPoint(x2, y1))
polyline.append(QgsPoint(x3, y2))
polyline.append(QgsPoint(x2, y3))
polyline.append(QgsPoint(x1, y2))
ft.setGeometry(QgsGeometry.fromPolygon([polyline]))
ft.setAttributes([x1, y1, x3, y3, id])
writer.addFeature(ft)
id += 1
count += 1
if int(math.fmod(count, count_update)) == 0:
progress.setPercentage(int(count / cells * 100))
def _hexagonGrid(self, writer, width, height, originX, originY,
hSpacing, vSpacing, progress):
ft = QgsFeature()
# To preserve symmetry, hspacing is fixed relative to vspacing
xVertexLo = 0.288675134594813 * vSpacing
xVertexHi = 0.577350269189626 * vSpacing
hSpacing = xVertexLo + xVertexHi
halfVSpacing = vSpacing / 2
columns = int(math.ceil(float(width) / hSpacing))
rows = int(math.ceil(float(height) / vSpacing))
cells = rows * columns
count_update = cells * 0.05
id = 1
count = 0
for col in range(columns):
# (column + 1) and (row + 1) calculation is used to maintain
# topology between adjacent shapes and avoid overlaps/holes
# due to rounding errors
x1 = originX + (col * hSpacing) # far left
x2 = x1 + (xVertexHi - xVertexLo) # left
x3 = originX + ((col + 1) * hSpacing) # right
x4 = x3 + (xVertexHi - xVertexLo) # far right
for row in range(rows):
if (col % 2) == 0:
y1 = originY - (((row * 2) + 0) * halfVSpacing) # hi
y2 = originY - (((row * 2) + 1) * halfVSpacing) # mid
y3 = originY - (((row * 2) + 2) * halfVSpacing) # lo
else:
y1 = originY - (((row * 2) + 1) * halfVSpacing) # hi
y2 = originY - (((row * 2) + 2) * halfVSpacing) # mid
y3 = originY - (((row * 2) + 3) * halfVSpacing) # lo
polyline = []
polyline.append(QgsPoint(x1, y2))
polyline.append(QgsPoint(x2, y1))
polyline.append(QgsPoint(x3, y1))
polyline.append(QgsPoint(x4, y2))
polyline.append(QgsPoint(x3, y3))
polyline.append(QgsPoint(x2, y3))
polyline.append(QgsPoint(x1, y2))
ft.setGeometry(QgsGeometry.fromPolygon([polyline]))
ft.setAttributes([x1, y1, x4, y3, id])
writer.addFeature(ft)
id += 1
count += 1
if int(math.fmod(count, count_update)) == 0:
progress.setPercentage(int(count / cells * 100))