/*
* Copyright (C) 2011-2012 Dr. John Lindsay <jlindsay@uoguelph.ca>
*
* 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 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package plugins;
import java.util.Date;
import whitebox.geospatialfiles.WhiteboxRaster;
import whitebox.interfaces.WhiteboxPlugin;
import whitebox.interfaces.WhiteboxPluginHost;
/**
* This tool performs a hillshade operation on an input digital elevation model (DEM).
*
* @author Dr. John Lindsay email: jlindsay@uoguelph.ca
*/
public class Hillshade implements WhiteboxPlugin {
private WhiteboxPluginHost myHost = null;
private String[] args;
/**
* Used to retrieve the plugin tool's name. This is a short, unique name
* containing no spaces.
*
* @return String containing plugin name.
*/
@Override
public String getName() {
return "Hillshade";
}
/**
* Used to retrieve the plugin tool's descriptive name. This can be a longer
* name (containing spaces) and is used in the interface to list the tool.
*
* @return String containing the plugin descriptive name.
*/
@Override
public String getDescriptiveName() {
return "Hillshade";
}
/**
* Used to retrieve a short description of what the plugin tool does.
*
* @return String containing the plugin's description.
*/
@Override
public String getToolDescription() {
return "This tool calculates a hillshade grid from a digital elevation model (DEM).";
}
/**
* Used to identify which toolboxes this plugin tool should be listed in.
*
* @return Array of Strings.
*/
@Override
public String[] getToolbox() {
String[] ret = {"SurfDerivatives"};
return ret;
}
/**
* Sets the WhiteboxPluginHost to which the plugin tool is tied. This is the
* class that the plugin will send all feedback messages, progress updates,
* and return objects.
*
* @param host The WhiteboxPluginHost that called the plugin tool.
*/
@Override
public void setPluginHost(WhiteboxPluginHost host) {
myHost = host;
}
/**
* Used to communicate feedback pop-up messages between a plugin tool and
* the main Whitebox user-interface.
*
* @param feedback String containing the text to display.
*/
private void showFeedback(String message) {
if (myHost != null) {
myHost.showFeedback(message);
} else {
System.out.println(message);
}
}
/**
* Used to communicate a return object from a plugin tool to the main
* Whitebox user-interface.
*
* @return Object, such as an output WhiteboxRaster.
*/
private void returnData(Object ret) {
if (myHost != null) {
myHost.returnData(ret);
}
}
private int previousProgress = 0;
private String previousProgressLabel = "";
/**
* Used to communicate a progress update between a plugin tool and the main
* Whitebox user interface.
*
* @param progressLabel A String to use for the progress label.
* @param progress Float containing the progress value (between 0 and 100).
*/
private void updateProgress(String progressLabel, int progress) {
if (myHost != null && ((progress != previousProgress)
|| (!progressLabel.equals(previousProgressLabel)))) {
myHost.updateProgress(progressLabel, progress);
}
previousProgress = progress;
previousProgressLabel = progressLabel;
}
/**
* Used to communicate a progress update between a plugin tool and the main
* Whitebox user interface.
*
* @param progress Float containing the progress value (between 0 and 100).
*/
private void updateProgress(int progress) {
if (myHost != null && progress != previousProgress) {
myHost.updateProgress(progress);
}
previousProgress = progress;
}
/**
* Sets the arguments (parameters) used by the plugin.
*
* @param args An array of string arguments.
*/
@Override
public void setArgs(String[] args) {
this.args = args.clone();
}
private boolean cancelOp = false;
/**
* Used to communicate a cancel operation from the Whitebox GUI.
*
* @param cancel Set to true if the plugin should be canceled.
*/
@Override
public void setCancelOp(boolean cancel) {
cancelOp = cancel;
}
private void cancelOperation() {
showFeedback("Operation cancelled.");
updateProgress("Progress: ", 0);
}
private boolean amIActive = false;
/**
* Used by the Whitebox GUI to tell if this plugin is still running.
*
* @return a boolean describing whether or not the plugin is actively being
* used.
*/
@Override
public boolean isActive() {
return amIActive;
}
/**
* Used to execute this plugin tool.
*/
@Override
public void run() {
amIActive = true;
String inputHeader = null;
String outputHeader = null;
final double radToDeg = 180 / Math.PI;
final double degToRad = Math.PI / 180;
double azimuth = 315 * degToRad;
double altitude = 45 * degToRad;
double zFactor = 1;
double z;
int progress;
int[] Dy = {-1, 0, 1, 1, 1, 0, -1, -1};
int[] Dx = {1, 1, 1, 0, -1, -1, -1, 0};
double sinTheta;
double cosTheta;
double tanSlope;
int row, col;
double fx, fy, aspect;
double gridRes, eightGridRes;
double[] N = new double[8];
double term1, term2, term3;
double outNoData = -32768;
if (args.length <= 0) {
showFeedback("Plugin parameters have not been set.");
return;
}
inputHeader = args[0];
outputHeader = args[1];
azimuth = (Double.parseDouble(args[2]) - 90) * degToRad;
altitude = Double.parseDouble(args[3]) * degToRad;
zFactor = Double.parseDouble(args[4]);
// check to see that the inputHeader and outputHeader are not null.
if ((inputHeader == null) || (outputHeader == null)) {
showFeedback("One or more of the input parameters have not been set properly.");
return;
}
try {
sinTheta = Math.sin(altitude);
cosTheta = Math.cos(altitude);
WhiteboxRaster inputFile = new WhiteboxRaster(inputHeader, "r");
inputFile.isReflectedAtEdges = true;
int rows = inputFile.getNumberRows();
int cols = inputFile.getNumberColumns();
gridRes = inputFile.getCellSizeX();
eightGridRes = 8 * gridRes;
//double Rad180 = 180 * degToRad;
//double Rad90 = 90 * degToRad;
double noData = inputFile.getNoDataValue();
if (inputFile.getXYUnits().toLowerCase().contains("deg") ||
inputFile.getProjection().toLowerCase().contains("geog")) {
// calculate a new z-conversion factor
double midLat = (inputFile.getNorth() - inputFile.getSouth()) / 2.0;
if (midLat <= 90 && midLat >= -90) {
midLat = Math.toRadians(midLat);
zFactor = 1.0 / (113200 * Math.cos(midLat));
}
}
WhiteboxRaster outputFile = new WhiteboxRaster(outputHeader, "rw", inputHeader, WhiteboxRaster.DataType.INTEGER, outNoData);
outputFile.setNoDataValue(outNoData);
outputFile.setPreferredPalette("grey.pal");
long[] histo = new long[256];
long numCells = 0;
int index;
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = inputFile.getValue(row, col);
if (z != noData) {
z = z * zFactor;
// get the neighbouring cell Z values
for (int c = 0; c < 8; c++) {
N[c] = inputFile.getValue(row + Dy[c], col + Dx[c]);
if (N[c] != noData) {
N[c] = N[c] * zFactor;
} else {
N[c] = z;
}
}
// calculate slope and aspect
fy = (N[6] - N[4] + 2 * (N[7] - N[3]) + N[0] - N[2]) / eightGridRes;
fx = (N[2] - N[4] + 2 * (N[1] - N[5]) + N[0] - N[6]) / eightGridRes;
if (fx != 0) {
tanSlope = Math.sqrt(fx * fx + fy * fy);
aspect = (180 - Math.atan(fy / fx) * radToDeg + 90 * (fx / Math.abs(fx))) * degToRad;
term1 = tanSlope / Math.sqrt(1 + tanSlope * tanSlope);
term2 = sinTheta / tanSlope;
term3 = cosTheta * Math.sin(azimuth - aspect);
z = term1 * (term2 - term3);
} else {
z = 0.5;
}
z = (int)(z * 255);
if (z < 0) {
z = 0;
}
histo[(int) z]++;
numCells++;
outputFile.setValue(row, col, z);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (int) (100f * row / (rows - 1));
updateProgress(progress);
}
// trim the display min and max values by clipPercent
double clipPercent = 0.01;
if (args.length >= 6) {
clipPercent = Double.parseDouble(args[5]) / 100.0;
}
int newMin = 0;
int newMax = 0;
double targetCellNum = numCells * clipPercent;
long sum = 0;
for (int c = 0; c < 256; c++) {
sum += histo[c];
if (sum >= targetCellNum) {
newMin = c;
break;
}
}
sum = 0;
for (int c = 255; c >= 0; c--) {
sum += histo[c];
if (sum >= targetCellNum) {
newMax = c;
break;
}
}
if (newMax > newMin) {
outputFile.setDisplayMinimum((double) newMin);
outputFile.setDisplayMaximum((double) newMax);
}
outputFile.addMetadataEntry("Created by the "
+ getDescriptiveName() + " tool.");
outputFile.addMetadataEntry("Created on " + new Date());
inputFile.close();
outputFile.close();
// returning a header file string displays the image.
returnData(outputHeader);
} catch (OutOfMemoryError oe) {
myHost.showFeedback("An out-of-memory error has occurred during operation.");
} catch (Exception e) {
myHost.showFeedback("An error has occurred during operation. See log file for details.");
myHost.logException("Error in " + getDescriptiveName(), e);
} finally {
updateProgress("Progress: ", 0);
// tells the main application that this process is completed.
amIActive = false;
myHost.pluginComplete();
}
}
}