/*
* 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 is used to generate a flow accumulation grid (i.e., contributing area) using the FD8 algorithm (Freeman, 1991).
*
* @author Dr. John Lindsay email: jlindsay@uoguelph.ca
*/
public class FlowAccumFD8 implements WhiteboxPlugin {
private WhiteboxPluginHost myHost = null;
private String[] args;
WhiteboxRaster DEM;
WhiteboxRaster output;
WhiteboxRaster tmpGrid;
double threshold = 0;
double noData = -32768;
int[] dX = new int[]{1, 1, 1, 0, -1, -1, -1, 0};
int[] dY = new int[]{-1, 0, 1, 1, 1, 0, -1, -1};
double power = 1;
double gridRes;
// Constants
private static final double LnOf2 = 0.693147180559945;
/**
* 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 "FlowAccumFD8";
}
/**
* 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 "FD8 Flow Accumulation";
}
/**
* Used to retrieve a short description of what the plugin tool does.
*
* @return String containing the plugin's description.
*/
@Override
public String getToolDescription() {
return "Performs an FD8 flow accumulation operation on a "
+ "specified 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 = {"FlowAccum"};
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, x, y;
float progress = 0;
double slope;
double z, z2;
int i;
double numInNeighbours;
boolean flag = false;
boolean logTransform = false;
String outputType = null;
if (args.length <= 0) {
showFeedback("Plugin parameters have not been set.");
return;
}
for (i = 0; i < args.length; i++) {
if (i == 0) {
inputHeader = args[i];
} else if (i == 1) {
outputHeader = args[i];
} else if (i == 2) {
power = Double.parseDouble(args[i]);
if (power > 10) {
power = 10;
}
} else if (i == 3) {
outputType = args[i].toLowerCase();
} else if (i == 4) {
logTransform = Boolean.parseBoolean(args[i]);
} else if (i == 5) {
if (!args[i].toLowerCase().contains("not specified")) {
threshold = Double.parseDouble(args[i]);
} else {
threshold = -9999;
}
}
}
// 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 {
DEM = new WhiteboxRaster(inputHeader, "r");
int rows = DEM.getNumberRows();
int cols = DEM.getNumberColumns();
noData = DEM.getNoDataValue();
gridRes = DEM.getCellSizeX();
output = new WhiteboxRaster(outputHeader, "rw",
inputHeader, WhiteboxRaster.DataType.FLOAT, 1);
output.setPreferredPalette("blueyellow.pal");
output.setDataScale(WhiteboxRaster.DataScale.CONTINUOUS);
output.setZUnits("dimensionless");
tmpGrid = new WhiteboxRaster(outputHeader.replace(".dep",
"_temp.dep"), "rw", inputHeader, WhiteboxRaster.DataType.FLOAT, noData);
tmpGrid.isTemporaryFile = true;
// Calculate the number of inflowing neighbours to each cell.
int loopNum = 1;
updateProgress("Loop " + loopNum + ":", 0);
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = DEM.getValue(row, col);
if (z != noData) {
numInNeighbours = 0;
for (i = 0; i < 8; i++) {
if (DEM.getValue(row + dY[i], col + dX[i]) > z) {
numInNeighbours++;
}
}
tmpGrid.setValue(row, col, numInNeighbours);
} else {
output.setValue(row, col, noData);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop " + loopNum + ":", (int) progress);
}
boolean somethingDone;
do {
loopNum++;
updateProgress("Loop " + loopNum + ":", 0);
somethingDone = false;
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
if (tmpGrid.getValue(row, col) == 0) { //there are no
//remaining inflowing neighbours, send it's current
//flow accum val downslope
FD8Accum(row, col);
somethingDone = true;
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop " + loopNum + ":", (int) progress);
}
} while (somethingDone);
loopNum++;
updateProgress("Loop " + loopNum + ":", 0);
if (outputType.equals("specific catchment area (sca)")) {
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = DEM.getValue(row, col);
if (z != noData) {
output.setValue(row, col,
output.getValue(row, col) * gridRes);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop " + loopNum + ":", (int) progress);
}
} else if (outputType.equals("total catchment area")) {
double gridCellArea = gridRes * gridRes;
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = output.getValue(row, col);
if (z != noData) {
output.setValue(row, col,
output.getValue(row, col) * gridCellArea);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop " + loopNum + ":", (int) progress);
}
}
if (logTransform) {
for (row = 0; row < rows; row++) {
for (col = 0; col < cols; col++) {
z = output.getValue(row, col);
if (z != noData) {
output.setValue(row, col,
Math.log(output.getValue(row, col)));
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (rows - 1));
updateProgress("Loop " + loopNum + ":", (int) progress);
}
} else {
output.setNonlinearity(0.2);
}
output.addMetadataEntry("Created by the "
+ getDescriptiveName() + " tool.");
output.addMetadataEntry("Created on " + new Date());
DEM.close();
tmpGrid.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();
}
}
int currentDepth;
final int maxDepth = 1000;
private void FD8Accum(int row, int col) {
double flowAccumVal = output.getValue(row, col);
double proportion = 0;
double totalRelief = 0;
int a, b;
byte c;
double z1 = DEM.getValue(row, col);
double z2;
double z;
currentDepth++;
if (currentDepth > maxDepth) {
return;
}
tmpGrid.setValue(row, col, -1);
if (threshold > flowAccumVal || threshold == -9999) {
for (c = 0; c < 8; c++) {
a = col + dX[c];
b = row + dY[c];
z2 = DEM.getValue(b, a);
if (z1 > z2 && z2 != noData) {
totalRelief += Math.pow((z1 - z2), power);
}
}
for (c = 0; c < 8; c++) {
a = col + dX[c];
b = row + dY[c];
z2 = DEM.getValue(b, a);
if (z1 > z2 && z2 != noData) {
proportion = Math.pow((z1 - z2), power) / totalRelief;
z = output.getValue(b, a);
output.setValue(b, a, z + flowAccumVal * proportion);
tmpGrid.setValue(b, a, tmpGrid.getValue(b, a) - 1);
if (tmpGrid.getValue(b, a) == 0) {
FD8Accum(b, a);
}
}
}
} else { //use a D8 method
//find the the steepest downslope neighbour
double slope;
double maxSlope = -999999999;
double diagGridRes = gridRes * Math.sqrt(2);
double dist = diagGridRes;
double flowDir = 255;
for (c = 0; c < 8; c++) {
a = col + dX[c];
b = row + dY[c];
z2 = DEM.getValue(b, a);
if (z1 > z2 && z2 != noData) {
slope = (z1 - z2) / dist;
if (slope > maxSlope) {
maxSlope = slope;
flowDir = c;
}
}
if (dist == gridRes) {
dist = diagGridRes;
} else {
dist = gridRes;
}
}
for (c = 0; c < 8; c++) {
a = col + dX[c];
b = row + dY[c];
z2 = DEM.getValue(b, a);
if (z1 > z2 && z2 != noData) {
if (c == flowDir) {
proportion = 1;
} else {
proportion = 0;
}
output.setValue(b, a, output.getValue(b, a)
+ flowAccumVal * proportion);
tmpGrid.setValue(b, a, tmpGrid.getValue(b, a) - 1);
if (tmpGrid.getValue(b, a) == 0) {
FD8Accum(b, a);
}
}
}
}
currentDepth--;
}
}