/*
* 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 can be used to extract channel networks from digital elevation models (DEMs) based on the Peucker and Douglas (1975) algorithm.
* @author Dr. John Lindsay email: jlindsay@uoguelph.ca
*/
public class ExtractValleysPeuckerAndDouglas 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 "ExtractValleysPeuckerAndDouglas";
}
/**
* 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 "Extract Valleys (Peucker And Douglas)";
}
/**
* Used to retrieve a short description of what the plugin tool does.
* @return String containing the plugin's description.
*/
@Override
public String getToolDescription() {
return "Identifies potential valley bottom grid cells.";
}
/**
* Used to identify which toolboxes this plugin tool should be listed in.
* @return Array of Strings.
*/
@Override
public String[] getToolbox() {
String[] ret = { "StreamAnalysis" };
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;
int row, col, rows, cols;
int progress = 0;
double z, maxZ, noData, outputNoData;
int i, whichCell;
int[] dX = new int[]{-1, 0, -1, 0};
int[] dY = new int[]{-1, -1, 0, 0};
int numScanCells = dX.length;
if (args.length <= 0) {
showFeedback("Plugin parameters have not been set.");
return;
}
inputHeader = args[0];
outputHeader = args[1];
boolean performLineThinning = Boolean.parseBoolean(args[2]);
// 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 {
WhiteboxRaster DEM = new WhiteboxRaster(inputHeader, "r");
rows = DEM.getNumberRows();
cols = DEM.getNumberColumns();
noData = DEM.getNoDataValue();
outputNoData = -32768;
WhiteboxRaster output = new WhiteboxRaster(outputHeader, "rw",
inputHeader, WhiteboxRaster.DataType.INTEGER, 1);
output.setNoDataValue(outputNoData);
output.setPreferredPalette("qual.pal");
output.setDataScale(WhiteboxRaster.DataScale.CATEGORICAL);
output.setZUnits("dimensionless");
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = DEM.getValue(row, col);
if (z != noData) {
maxZ = z;
whichCell = 3;
for (i = 0; i < (numScanCells - 1); i++) {
z = DEM.getValue(row + dY[i], col + dX[i]);
if (z != noData) {
if (z > maxZ) {
maxZ = z;
whichCell = i;
}
}
}
output.setValue(row + dY[whichCell], col + dX[whichCell], 0);
} else {
output.setValue(row, col, outputNoData);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (int) (100f * row / (rows - 1));
updateProgress(progress);
}
if (performLineThinning) {
long counter = 0;
int loopNum = 0;
int a;
dX = new int[]{1, 1, 1, 0, -1, -1, -1, 0};
dY = new int[]{-1, 0, 1, 1, 1, 0, -1, -1};
int[][] elements = {{6, 7, 0, 4, 3, 2}, {7, 0, 1, 3, 5},
{0, 1, 2, 4, 5, 6}, {1, 2, 3, 5, 7},
{2, 3, 4, 6, 7, 0}, {3, 4, 5, 7, 1},
{4, 5, 6, 0, 1, 2}, {5, 6, 7, 1, 3}};
double[][] vals = {{0, 0, 0, 1, 1, 1}, {0, 0, 0, 1, 1},
{0, 0, 0, 1, 1, 1}, {0, 0, 0, 1, 1},
{0, 0, 0, 1, 1, 1}, {0, 0, 0, 1, 1},
{0, 0, 0, 1, 1, 1}, {0, 0, 0, 1, 1}};
double[] neighbours = new double[8];
boolean patternMatch = false;
do {
loopNum++;
updateProgress("Loop Number " + loopNum + ":", 0);
counter = 0;
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = output.getValue(row, col);
if (z > 0 && z != noData) {
// fill the neighbours array
for (i = 0; i < 8; i++) {
neighbours[i] = output.getValue(row + dY[i], col + dX[i]);
}
for (a = 0; a < 8; a++) {
// scan through element
patternMatch = true;
for (i = 0; i < elements[a].length; i++) {
if (neighbours[elements[a][i]] != vals[a][i]) {
patternMatch = false;
}
}
if (patternMatch) {
output.setValue(row, col, 0);
counter++;
}
}
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (int) (100f * row / (rows - 1));
updateProgress(progress);
}
} while (counter > 0);
}
output.addMetadataEntry("Created by the "
+ getDescriptiveName() + " tool.");
output.addMetadataEntry("Created on " + new Date());
DEM.close();
output.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();
}
}
}