/*
* Copyright (C) 2014 Jan Seibert (jan.seibert@geo.uzh.ch) and
* Marc Vis (marc.vis@geo.uzh.ch)
*
* 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.geospatialfiles.WhiteboxRasterBase;
import whitebox.interfaces.WhiteboxPlugin;
import whitebox.interfaces.WhiteboxPluginHost;
/**
* This tool is used to generate a streamheads grid by applying the MDInf algorithm (Seibert and McGlynn, 2007) and using a threshold value for stream initiation.
* @author Dr. John Lindsay email: jlindsay@uoguelph.ca
*/
public class StreamHeadsMDInf implements WhiteboxPlugin {
private WhiteboxPluginHost myHost = null;
private String[] args;
double pi = Math.PI;
WhiteboxRaster dem;
WhiteboxRaster output;
WhiteboxRaster tmpArea;
WhiteboxRaster tmpCount;
int depth = 0;
double mdInfPower = 1;
double caThreshold;
String caThresholdType;
int[] xd = new int[]{0, -1, -1, -1, 0, 1, 1, 1};
int[] yd = new int[]{-1, -1, 0, 1, 1, 1, 0, -1};
double[] dd = new double[]{1, Math.sqrt(2), 1, Math.sqrt(2), 1, Math.sqrt(2), 1, Math.sqrt(2)};
double gridRes = 1;
/**
* 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 "StreamHeadsMDInf";
}
/**
* 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 "Find Streamheads (MDInf)";
}
/**
* Used to retrieve a short description of what the plugin tool does.
* @return String containing the plugin's description.
*/
@Override
public String getToolDescription() {
return "Finds streamheads for the specified digital elevation model (DEM) using the MDInf algorithm.";
}
/**
* Used to identify which toolboxes this plugin tool should be listed in.
* @return Array of Strings.
*/
@Override
public String[] getToolbox() {
String[] ret = { "Streamheads" };
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 demHeader = null;
String outputHeader = null;
int numRows;
int numCols;
int row;
int col;
double z;
int i;
int c;
int x, y;
double noData;
float progress = 0;
if (args.length <= 0) {
showFeedback("Plugin parameters have not been set.");
return;
}
for (i = 0; i < args.length; i++) {
if (i == 0) {
demHeader = args[i];
} else if (i == 1) {
outputHeader = args[i];
} else if (i == 2) {
mdInfPower = Double.parseDouble(args[i]);
} else if (i == 3) {
caThreshold = Double.parseDouble(args[i]);
} else if (i == 4) {
caThresholdType = args[i].toLowerCase();
}
}
// check to see that the inputHeader and outputHeader are not null.
if ((demHeader == null) || (outputHeader == null)) {
showFeedback("One or more of the input parameters have not been set properly.");
return;
}
try {
dem = new WhiteboxRaster(demHeader, "r");
numRows = dem.getNumberRows();
numCols = dem.getNumberColumns();
noData = dem.getNoDataValue();
gridRes = dem.getCellSizeX();
output = new WhiteboxRaster(outputHeader, "rw", demHeader, WhiteboxRaster.DataType.FLOAT, 0);
output.setPreferredPalette("blueyellow.pal");
output.setDataScale(WhiteboxRasterBase.DataScale.CONTINUOUS);
output.setZUnits("dimensionless");
tmpArea = new WhiteboxRaster(outputHeader.replace(".dep", "_tmp1.dep"), "rw", demHeader, WhiteboxRaster.DataType.FLOAT, noData);
tmpArea.isTemporaryFile = true;
tmpCount = new WhiteboxRaster(outputHeader.replace(".dep", "_tmp1.dep"), "rw", demHeader, WhiteboxRaster.DataType.FLOAT, noData);
tmpCount.isTemporaryFile = true;
switch (caThresholdType) {
case "specific catchment area (sca)":
caThreshold = caThreshold / gridRes;
break;
case "total catchment area":
caThreshold = caThreshold / (gridRes * gridRes);
break;
default: // case "Number of upslope grid cells"
break;
}
// Calculate the number of inflowing neighbours to each grid cell and initialize the output grid
updateProgress("Loop 1 of 2:", 0);
for (row = 0; row < numRows; row++) {
for (col = 0; col < numCols; col++) {
z = dem.getValue(row, col);
if (z != noData) {
i = 0;
for (c = 0; c < 8; c++) {
x = col + xd[c];
y = row + yd[c];
if (z < dem.getValue(y, x)) {
i++;
}
}
tmpArea.setValue(row, col, 1);
tmpCount.setValue(row, col, i);
output.setValue(row, col, -1);
} else {
tmpArea.setValue(row, col, noData);
output.setValue(row, col, noData);
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (numRows - 1));
updateProgress("Loop 1 of 2:", (int) progress);
}
// Perform the flow accumulation
updateProgress("Loop 2 of 2:", 0);
for (row = 0; row < numRows; row++) {
for (col = 0; col < numCols; col++) {
if (dem.getValue(row, col) != noData){
if (tmpCount.getValue(row, col) == 0) { //there are no
//remaining inflowing neighbours, send it's current
//flow accum val downslope
MDInfAccum(row, col, mdInfPower, noData);
}
}
}
if (cancelOp) {
cancelOperation();
return;
}
progress = (float) (100f * row / (numRows - 1));
updateProgress("Loop 2 of 2:", (int) progress);
}
output.addMetadataEntry("Created by the " + getDescriptiveName() + " tool.");
output.addMetadataEntry("Created on " + new Date());
dem.close();
output.close();
tmpArea.close();
tmpCount.close();
// returning a header file string displays the image.
returnData(outputHeader);
} catch (Exception e) {
showFeedback(e.getMessage());
} finally {
updateProgress("Progress: ", 0);
// tells the main application that this process is completed.
amIActive = false;
myHost.pluginComplete();
}
}
private void MDInfAccum(int row, int col, double hExp, double noData) {
double z = dem.getValue(row, col);
double flowAccumVal = tmpArea.getValue(row, col);
int i, ii;
double p1, p2;
double z1, z2;
double nx, ny, nz;
double hr, hs;
double[] rFacet = new double[8];
double[] sFacet = new double[]{noData, noData, noData, noData, noData, noData, noData, noData};
double[] valley = new double[8];
double[] portion = new double[8];
double valleySum = 0;
double valleyMax = 0;
int iMax = 0;
int a, b;
int c;
tmpCount.setValue(row, col, -1);
if (caThreshold >= flowAccumVal || caThreshold == noData) {
if (flowAccumVal != noData) {
output.setValue(row, col, 0);
}
// Compute slope and direction for each of the triangular facets
for (c = 0; c < 8; c++){
i = c;
ii = (i + 1) % 8;
p1 = dem.getValue(row + yd[i], col + xd[i]);
p2 = dem.getValue(row + yd[ii], col + xd[ii]);
if ((p1 != noData) && (p2 != noData)) {
// Calculate the elevation difference between the centerpoint and the points p1 and p2
z1 = p1 - z;
z2 = p2 - z;
// Calculate the coordinates of the normal to the triangular facet
nx = (yd[i] * z2 - yd[ii] * z1) * gridRes;
ny = (xd[ii] * z1 - xd[i] * z2) * gridRes;
nz = (xd[i] * yd[ii] - xd[ii] * yd[i]) * Math.pow(gridRes, 2);
// Calculate the downslope direction of the triangular facet
if (nx == 0) {
if (ny >= 0) {
hr = 0;
} else {
hr = pi;
}
} else {
if (nx >= 0) {
hr = pi / 2 - Math.atan(ny / nx);
} else {
hr = 3 * pi / 2 - Math.atan(ny / nx);
}
}
// Calculate the slope of the triangular facet
hs = -Math.tan(Math.acos(nz / (Math.sqrt(Math.pow(nx, 2) + Math.pow(ny, 2) + Math.pow(nz, 2)))));
// If the downslope direction is outside the triangular facet, then use the direction of p1 or p2
if ((hr < (i) * pi / 4) || (hr > (i + 1) * pi / 4)) {
if (p1 < p2) {
hr = i * pi / 4;
hs = (z - p1) / (dd[i] * gridRes);
} else {
hr = ii * pi / 4;
hs = (z - p2) / (dd[ii] * gridRes);
}
}
rFacet[c] = hr;
sFacet[c] = hs;
} else {
if ((p1 != noData) && (p1 < z)) {
hr = ((float) i) / 4 * pi;
hs = (z - p1) / (dd[ii] * gridRes);
rFacet[c] = hr;
sFacet[c] = hs;
}
}
}
// Compute the total area of the triangular facets where water is flowing to
for (c = 0; c < 8; c++){
i = c;
ii = (i + 1) % 8;
if (sFacet[i] > 0) { // If the slope is downhill
if ((rFacet[i] > (i * pi / 4)) && (rFacet[i] < ((i + 1) * pi / 4))) { // If the downslope direction is inside the 45 degrees of the triangular facet
valley[i] = sFacet[i];
} else if (rFacet[i] == rFacet[ii]) { // If two adjacent triangular facets have the same downslope direction
valley[i] = sFacet[i];
} else if ((sFacet[ii] == noData) && (rFacet[i] == ((i + 1) * pi / 4))) { // If the downslope direction is on the border of the current triangular facet, and the corresponding neigbour// s downslope is NoData
valley[i] = sFacet[i];
} else {
ii = (i + 7) % 8;
if ((sFacet[ii] == noData) && (rFacet[i] == (i * pi / 4))) { // If the downslope direction is on the other border of the current triangular facet, and the corresponding neigbour// s downslope is NoData
valley[i] = sFacet[i];
}
}
}
valleySum = valleySum + Math.pow(valley[i], hExp);
if (valleyMax < valley[i]) {
iMax = i;
valleyMax = valley[i];
}
}
// Compute the proportional contribution for each of the triangular facets
if (valleySum > 0) {
if (hExp < 10) {
for (i = 0; i < 8; i++) {
valley[i] = (Math.pow(valley[i], hExp)) / valleySum;
portion[i] = 0;
}
} else {
for (i = 0; i < 8; i++) {
if (i != iMax) {
valley[i] = 0;
} else {
valley[i] = 1;
}
portion[i] = 0;
}
}
if (rFacet[7] == 0) {
rFacet[7] = 2 * pi;
}
// Compute the contribution to each of the neighbouring gridcells
for (c = 0; c < 8; c++){
i = c;
ii = (i + 1) % 8;
if (valley[i] > 0) {
portion[i] = portion[i] + valley[i] * ((i + 1) * pi / 4 - rFacet[i]) / (pi / 4);
portion[ii] = portion[ii] + valley[i] * (rFacet[i] - (i) * pi / 4) / (pi / 4);
}
}
// Apply the flow accumulation to each of the neighbouring gridcells
for (c = 0; c < 8; c++){
if (portion[c] > 0) {
a = col + xd[c];
b = row + yd[c];
if (tmpArea.getValue(b, a) != noData) {
tmpArea.incrementValue(b, a, flowAccumVal * portion[c]);
}
}
}
}
for (c = 0; c < 8; c++){
a = col + xd[c];
b = row + yd[c];
z1 = dem.getValue(b, a);
if ((z > z1) && (z1 != noData)) {
tmpCount.incrementValue(b, a, -1);
if (tmpCount.getValue(b, a) == 0) {
MDInfAccum(b, a, hExp, noData);
}
}
}
} else { // Use a D8 method
double slope;
double maxSlope = Double.MIN_VALUE;
int flowDir = 255;
if (flowAccumVal != noData & caThreshold != noData) {
if (output.getValue(row, col) != 0) {
output.setValue(row, col, 1);
}
tmpArea.setValue(row, col, caThreshold);
}
// Find the neighbour with the steepest slope
for (c = 0; c < 8; c++){
a = col + xd[c];
b = row + yd[c];
z1 = dem.getValue(b, a);
if ((z > z1) && (z1 != noData)) {
slope = (z - z1) / dd[c];
if (slope > maxSlope) {
maxSlope = slope;
flowDir = c;
}
}
}
// Update neighbours (actually only the steepest slope neighbour)
for (c = 0; c < 8; c++){
a = col + xd[c];
b = row + yd[c];
z1 = dem.getValue(b, a);
if ((z > z1) && (z1 != noData)) {
if (c == flowDir & tmpArea.getValue(b, a) != noData) {
output.setValue(b, a, 0); // Cell (b, a) receives water from the current creek cell
tmpArea.incrementValue(b, a, caThreshold);
}
tmpCount.incrementValue(b, a, -1);
if (tmpCount.getValue(b, a) == 0) {
MDInfAccum(b, a, hExp, noData);
}
}
}
}
}
}