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[processing] add Points from lines algorithm (still needs some improv…
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# -*- coding: utf-8 -*- | ||
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""" | ||
*************************************************************************** | ||
PointsFromLines.py | ||
--------------------- | ||
Date : August 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. * | ||
* * | ||
*************************************************************************** | ||
""" | ||
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__author__ = 'Alexander Bruy' | ||
__date__ = 'August 2013' | ||
__copyright__ = '(C) 2013, Alexander Bruy' | ||
# This will get replaced with a git SHA1 when you do a git archive | ||
__revision__ = '$Format:%H$' | ||
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from PyQt4.QtCore import * | ||
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from osgeo import gdal | ||
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from qgis.core import * | ||
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from sextante.core.GeoAlgorithm import GeoAlgorithm | ||
from sextante.core.QGisLayers import QGisLayers | ||
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from sextante.parameters.ParameterRaster import ParameterRaster | ||
from sextante.parameters.ParameterVector import ParameterVector | ||
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from sextante.outputs.OutputVector import OutputVector | ||
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from sextante.algs import QGISUtils as utils | ||
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class PointsFromLines(GeoAlgorithm): | ||
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INPUT_RASTER = "INPUT_RASTER" | ||
RASTER_BAND = "RASTER_BAND" | ||
INPUT_VECTOR = "INPUT_VECTOR" | ||
OUTPUT_LAYER = "OUTPUT_LAYER" | ||
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def defineCharacteristics(self): | ||
self.name = "Points from lines" | ||
self.group = "Vector geometry tools" | ||
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self.addParameter(ParameterRaster(self.INPUT_RASTER, "Raster layer")) | ||
self.addParameter(ParameterVector(self.INPUT_VECTOR, "Vector layer", [ParameterVector.VECTOR_TYPE_LINE])) | ||
self.addOutput(OutputVector(self.OUTPUT_LAYER, "Output layer")) | ||
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def processAlgorithm(self, progress): | ||
layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT_VECTOR)) | ||
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rasterPath = unicode(self.getParameterValue(self.INPUT_RASTER)) | ||
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rasterDS = gdal.Open(rasterPath, gdal.GA_ReadOnly) | ||
geoTransform = rasterDS.GetGeoTransform() | ||
rasterDS = None | ||
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fields = QgsFields() | ||
fields.append(QgsField("id", QVariant.Int, "", 10, 0)) | ||
fields.append(QgsField("line_id", QVariant.Int, "", 10, 0)) | ||
fields.append(QgsField("point_id", QVariant.Int, "", 10, 0)) | ||
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writer = self.getOutputFromName(self.OUTPUT_LAYER).getVectorWriter(fields.toList(), QGis.WKBPoint, layer.crs()) | ||
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outFeature = QgsFeature() | ||
outFeature.setFields(fields) | ||
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self.fid = 0 | ||
self.lineId = 0 | ||
self.pointId = 0 | ||
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current = 0 | ||
features = QGisLayers.features(layer) | ||
total = 100.0 / len(features) | ||
for f in features: | ||
geom = f.geometry() | ||
if geom.isMultipart(): | ||
lines = geom.asMultiPolyline() | ||
for line in lines: | ||
for i in xrange(len(line) - 1): | ||
p1 = line[i] | ||
p2 = line[i + 1] | ||
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x1, y1 = utils.mapToPixel(p1.x(), p1.y(), geoTransform) | ||
x2, y2 = utils.mapToPixel(p2.x(), p2.y(), geoTransform) | ||
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self.buildLine(x1, y1, x2, y2, geoTransform, writer, outFeature) | ||
else: | ||
points = geom.asPolyline() | ||
for i in xrange(len(points) - 1): | ||
p1 = points[i] | ||
p2 = points[i + 1] | ||
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x1, y1 = utils.mapToPixel(p1.x(), p1.y(), geoTransform) | ||
x2, y2 = utils.mapToPixel(p2.x(), p2.y(), geoTransform) | ||
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self.buildLine(x1, y1, x2, y2, geoTransform, writer, outFeature) | ||
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self.pointId = 0 | ||
self.lineId += 1 | ||
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current += 1 | ||
progress.setPercentage(int(current * total)) | ||
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del writer | ||
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def buildLine(self, startX, startY, endX, endY, geoTransform, writer, feature): | ||
point = QgsPoint() | ||
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if startX == endX: | ||
if startY > endY: | ||
startY, endY = endY, startY | ||
row = startX | ||
for col in xrange(startY, endY + 1): | ||
self.createPoint(row, col, geoTransform, writer, feature) | ||
elif startY == endY: | ||
if startX > endX: | ||
startX, endX = endX, startX | ||
col = startY | ||
for row in xrange(startX, endX + 1): | ||
self.createPoint(row, col, geoTransform, writer, feature) | ||
else: | ||
width = endX - startX | ||
height = endY - startY | ||
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if width < 0: | ||
dx1 = -1 | ||
dx2 = -1 | ||
else: | ||
dx1 = 1 | ||
dx2 = 1 | ||
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if height < 0: | ||
dy1 = -1 | ||
else: | ||
dy1 = 1 | ||
dy2 = 0 | ||
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longest = abs(width) | ||
shortest = abs(height) | ||
if not longest > shortest: | ||
longest, shortest = shortest, longest | ||
if height < 0: | ||
dy2 = -1 | ||
else: | ||
dy2 = 1 | ||
dx2 = 0 | ||
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err = longest / 2 | ||
for i in xrange(longest + 1): | ||
self.createPoint(startX, startY, geoTransform, writer, feature) | ||
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err += shortest | ||
if not err < longest: | ||
err = err - longest | ||
startX += dx1 | ||
startY += dy1 | ||
else: | ||
startX += dx2 | ||
startY += dy2 | ||
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def createPoint(self, pX, pY, geoTransform, writer, feature): | ||
x, y = utils.pixelToMap(pX, pY, geoTransform) | ||
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feature.setGeometry(QgsGeometry.fromPoint(QgsPoint(x, y))) | ||
feature["id"] = self.fid | ||
feature["line_id"] = self.lineId | ||
feature["point_id"] = self.pointId | ||
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self.fid += 1 | ||
self.pointId +=1 | ||
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writer.addFeature(feature) |