QGIS/python/plugins/sextante/grass/nviz.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    nviz.py
    ---------------------
    Date                 : August 2012
    Copyright            : (C) 2012 by Victor Olaya
    Email                : volayaf 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__ = 'Victor Olaya'
__date__ = 'August 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'

import os
from qgis.core import *
from sextante.parameters.ParameterMultipleInput import ParameterMultipleInput
from sextante.grass.GrassUtils import GrassUtils
from sextante.core.GeoAlgorithm import GeoAlgorithm
from PyQt4 import QtGui
from sextante.core.SextanteUtils import SextanteUtils
from sextante.parameters.ParameterExtent import ParameterExtent
from sextante.parameters.ParameterNumber import ParameterNumber
from sextante.parameters.ParameterRaster import ParameterRaster
from sextante.core.QGisLayers import QGisLayers
import time

class nviz(GeoAlgorithm):

    ELEVATION = "ELEVATION"
    VECTOR = "VECTOR"
    GRASS_REGION_EXTENT_PARAMETER = "GRASS_REGION_PARAMETER"
    GRASS_REGION_CELLSIZE_PARAMETER = "GRASS_REGION_CELLSIZE_PARAMETER"

    def getIcon(self):
        return  QtGui.QIcon(os.path.dirname(__file__) + "/../images/grass.png")

    def defineCharacteristics(self):
        self.name = "nviz"
        self.group = "Visualization(NVIZ)"
        self.addParameter(ParameterMultipleInput(nviz.ELEVATION, "Elevation layers", ParameterMultipleInput.TYPE_RASTER, True))
        self.addParameter(ParameterMultipleInput(nviz.VECTOR, "Vector layers", ParameterMultipleInput.TYPE_VECTOR_ANY, True))
        self.addParameter(ParameterExtent(nviz.GRASS_REGION_EXTENT_PARAMETER, "GRASS region extent"))
        self.addParameter(ParameterNumber(self.GRASS_REGION_CELLSIZE_PARAMETER, "GRASS region cellsize (leave 0 for default)", 0, None, 0.0))

    def processAlgorithm(self, progress):
        commands = []
        vector = self.getParameterValue(self.VECTOR);
        elevation = self.getParameterValue(self.ELEVATION);

        region = str(self.getParameterValue(self.GRASS_REGION_EXTENT_PARAMETER))
        regionCoords = region.split(",")
        command = "g.region "
        command += "n=" + str(regionCoords[3])
        command +=" s=" + str(regionCoords[2])
        command +=" e=" + str(regionCoords[1])
        command +=" w=" + str(regionCoords[0])
        cellsize = self.getParameterValue(self.GRASS_REGION_CELLSIZE_PARAMETER)
        if cellsize:
            command +=" res=" + str(cellsize);
        else:
            command +=" res=" + str(self.getDefaultCellsize())
        commands.append(command)

        command = "nviz"
        if vector:
            layers = vector.split(";")
            for layer in layers:
                cmd, newfilename = self.exportVectorLayer(layer)
                commands.append(cmd)
                vector = vector.replace(layer, newfilename)
            command += (" vector=" + vector.replace(";", ","))
        if elevation:
            layers = elevation.split(";")
            for layer in layers:
                cmd, newfilename = self.exportRasterLayer(layer)
                commands.append(cmd)
                elevation = elevation.replace(layer, newfilename)
            command += (" elevation=" + elevation.replace(";", ","))
        if elevation is None and vector is None:
            command += " -q"
        commands.append(command)
        GrassUtils.createTempMapset();
        GrassUtils.executeGrass(commands, progress)

    def getTempFilename(self):
        filename =  "tmp" + str(time.time()).replace(".","") + str(SextanteUtils.getNumExportedLayers())
        return filename

    def exportVectorLayer(self,layer):
        destFilename = self.getTempFilename()
        command = "v.in.ogr"
        command += " min_area=-1"
        command +=" dsn=\"" + os.path.dirname(layer) + "\""
        command +=" layer=" + os.path.basename(layer)[:-4]
        command +=" output=" + destFilename;
        command +=" --overwrite -o"
        return command, destFilename

    def exportRasterLayer(self, layer):
        destFilename = self.getTempFilename()
        command = "r.in.gdal"
        command +=" input=\"" + layer + "\""
        command +=" band=1"
        command +=" out=" + destFilename;
        command +=" --overwrite -o"
        return command, destFilename

    def getDefaultCellsize(self):
        cellsize = 0
        for param in self.parameters:
            if param.value:
                if isinstance(param, ParameterRaster):
                    if isinstance(param.value, QgsRasterLayer):
                        layer = param.value
                    else:
                        layer = QGisLayers.getObjectFromUri(param.value)
                    cellsize = max(cellsize, (layer.extent().xMaximum() - layer.extent().xMinimum())/layer.width())

                elif isinstance(param, ParameterMultipleInput):
                    layers = param.value.split(";")
                    for layername in layers:
                        layer = QGisLayers.getObjectFromUri(layername)
                        if isinstance(layer, QgsRasterLayer):
                            cellsize = max(cellsize, (layer.extent().xMaximum() - layer.extent().xMinimum())/layer.width())

        if cellsize == 0:
            cellsize = 1
        return cellsize