[FEATURE] add Densify geometries tool to SEXTANTE

qgis · Oct 4, 2012 · 708b679 · 708b679
1 parent 13b4d7f
commit 708b679
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Showing 2 changed files with 137 additions and 2 deletions.
diff --git a/python/plugins/sextante/ftools/DensifyGeometries.py b/python/plugins/sextante/ftools/DensifyGeometries.py
@@ -0,0 +1,133 @@
+import os.path
+
+from PyQt4 import QtGui
+from PyQt4.QtCore import *
+
+from qgis.core import *
+
+from sextante.core.GeoAlgorithm import GeoAlgorithm
+from sextante.core.QGisLayers import QGisLayers
+from sextante.core.SextanteLog import SextanteLog
+
+from sextante.parameters.ParameterVector import ParameterVector
+from sextante.parameters.ParameterNumber import ParameterNumber
+from sextante.parameters.ParameterBoolean import ParameterBoolean
+
+from sextante.outputs.OutputVector import OutputVector
+
+class DensifyGeometries(GeoAlgorithm):
+
+    INPUT = "INPUT"
+    VERTICES = "VERTICES"
+    USE_SELECTION = "USE_SELECTION"
+    OUTPUT = "OUTPUT"
+
+    #def getIcon(self):
+    #    return QtGui.QIcon(os.path.dirname(__file__) + "/icons/de.png")
+
+    def defineCharacteristics(self):
+        self.name = "Densify geometries"
+        self.group = "Geometry tools"
+
+        self.addParameter(ParameterVector(self.INPUT, "Input layer", ParameterVector.VECTOR_TYPE_ANY))
+        self.addParameter(ParameterNumber(self.VERTICES, "Vertices to add", 1, 10000000, 1))
+        self.addParameter(ParameterBoolean(self.USE_SELECTION, "Use only selected features", False))
+
+        self.addOutput(OutputVector(self.OUTPUT, "Simplified layer"))
+
+    def processAlgorithm(self, progress):
+        settings = QSettings()
+        encoding = settings.value( "/UI/encoding", "System" ).toString()
+
+        layer = QGisLayers.getObjectFromUri(self.getParameterValue(self.INPUT))
+        useSelection = self.getParameterValue(self.USE_SELECTION)
+        vertices =self.getParameterValue(self.VERTICES)
+        output = self.getOutputValue(self.OUTPUT)
+
+        isPolygon = layer.geometryType() == QGis.Polygon
+
+        provider = layer.dataProvider()
+        layer.select(layer.pendingAllAttributesList())
+
+        writer = self.getOutputFromName(self.OUTPUT).getVectorWriter(layer.pendingFields(),
+                     layer.wkbType(), provider.crs())
+
+        current = 0
+        if useSelection:
+            total = 100.0 / float(len(layer.selectedFeatures()))
+            for f in selection:
+                featGeometry = QgsGeometry(f.geometry())
+                attrMap = f.attributeMap()
+                newGeometry = self.densifyGeometry(featGeometry, int(vertices), isPolygon)
+
+                feature = QgsFeature()
+                feature.setGeometry(newGeometry)
+                feature.setAttributeMap(attrMap)
+                writer.addFeature(feature)
+
+                current += 1
+                progress.setPercentage(int(current * total))
+        else:
+            total = 100.0 / float(provider.featureCount())
+            f = QgsFeature()
+            while layer.nextFeature(f):
+                featGeometry = QgsGeometry(f.geometry())
+                attrMap = f.attributeMap()
+                newGeometry = self.densifyGeometry(featGeometry, int(vertices), isPolygon)
+
+                feature = QgsFeature()
+                feature.setGeometry(newGeometry)
+                feature.setAttributeMap(attrMap)
+                writer.addFeature(feature)
+
+                current += 1
+                progress.setPercentage(int(current * total))
+
+        del writer
+
+    def densifyGeometry(self, geometry, pointsNumber, isPolygon):
+        output = []
+        if isPolygon:
+            if geometry.isMultipart():
+                polygons = geometry.asMultiPolygon()
+                for poly in polygons:
+                    p = []
+                    for ring in poly:
+                        p.append(self.densify(ring, pointsNumber))
+                    output.append(p)
+                return QgsGeometry.fromMultiPolygon(output)
+            else:
+                rings = geometry.asPolygon()
+                for ring in rings:
+                    output.append(self.densify(ring, pointsNumber))
+                return QgsGeometry.fromPolygon(output)
+        else:
+            if geometry.isMultipart():
+                lines = geometry.asMultiPolyline()
+                for points in lines:
+                    output.append(self.densify(points, pointsNumber))
+                return QgsGeometry.fromMultiPolyline(output)
+            else:
+                points = geometry.asPolyline()
+                output = self.densify(points, pointsNumber)
+                return QgsGeometry.fromPolyline(output)
+
+    def densify(self, polyline, pointsNumber):
+        output = []
+        if pointsNumber != 1:
+            multiplier = 1.0 / float(pointsNumber + 1)
+        else:
+            multiplier = 1
+        for i in xrange(len(polyline) - 1):
+            p1 = polyline[i]
+            p2 = polyline[i + 1]
+            output.append(p1)
+            for j in xrange(pointsNumber):
+                delta = multiplier * (j + 1)
+                x = p1.x() + delta * (p2.x() - p1.x())
+                y = p1.y() + delta * (p2.y() - p1.y())
+                output.append(QgsPoint( x, y ))
+                if j + 1 == pointsNumber:
+                    break
+        output.append(polyline[len(polyline) - 1])
+        return output
diff --git a/python/plugins/sextante/ftools/FToolsAlgorithmProvider.py b/python/plugins/sextante/ftools/FToolsAlgorithmProvider.py
@@ -24,6 +24,7 @@
 from sextante.ftools.VoronoiPolygons import VoronoiPolygons
 from sextante.ftools.LinesToPolygons import LinesToPolygons
 from sextante.ftools.PolygonsToLines import PolygonsToLines
+from sextante.ftools.DensifyGeometries import DensifyGeometries
 from sextante.ftools.SimplifyGeometries import SimplifyGeometries
 from sextante.ftools.ExportGeometryInfo import ExportGeometryInfo
 from sextante.ftools.MultipartToSingleparts import MultipartToSingleparts
@@ -55,8 +56,9 @@ def __init__(self):
                         # data management
                         # geometry
                         ExportGeometryInfo(), Centroids(), Delaunay(), VoronoiPolygons(),
-                        SimplifyGeometries(), MultipartToSingleparts(), SinglePartsToMultiparts(),
-                        PolygonsToLines(), LinesToPolygons(), ExtractNodes(),
+                        SimplifyGeometries(), DensifyGeometries(), MultipartToSingleparts(),
+                        SinglePartsToMultiparts(), PolygonsToLines(), LinesToPolygons(),
+                        ExtractNodes(),
                         # geoprocessing
                         ConvexHull(), FixedDistanceBuffer(), VariableDistanceBuffer(),
                         Dissolve(), Difference(), Intersection(), Union(), Clip(),