Geofences

1 files changed, 160 insertions, 0 deletions

diff --git a/src/org/traccar/geofence/GeofencePolygon.java b/src/org/traccar/geofence/GeofencePolygon.java
new file mode 100644
index 000000000..08178375a
--- /dev/null
+++ b/src/org/traccar/geofence/GeofencePolygon.java
@@ -0,0 +1,160 @@
+package org.traccar.geofence;
+
+import java.text.ParseException;
+import java.util.ArrayList;
+
+public class GeofencePolygon extends GeofenceGeometry {
+
+    public GeofencePolygon() {
+        super();
+    }
+
+    public GeofencePolygon(String wkt) throws ParseException {
+        super();
+        fromWKT(wkt);
+    }
+
+    private static class Coordinate {
+
+        public static final double DEGREE360 = 360;
+
+        private double lat;
+        private double lon;
+
+        public double getLat() {
+            return lat;
+        }
+
+        public void setLat(double lat) {
+            this.lat = lat;
+        }
+
+        public double getLon() {
+            return lon;
+        }
+
+        // Need not to confuse algorithm by the abrupt reset of longitude
+        public double getLon360() {
+            return lon + DEGREE360;
+        }
+
+        public void setLon(double lon) {
+            this.lon = lon;
+        }
+    }
+
+    private ArrayList<Coordinate> coordinates;
+
+    private double[] constant;
+    private double[] multiple;
+
+    private void precalc() {
+        if (coordinates == null) {
+            return;
+        }
+        int polyCorners = coordinates.size();
+        int i;
+        int j = polyCorners - 1;
+
+        if (constant != null) {
+            constant = null;
+        }
+        if (multiple != null) {
+            multiple = null;
+        }
+
+        constant = new double[polyCorners];
+        multiple = new double[polyCorners];
+
+
+        for (i = 0; i < polyCorners; j = i++) {
+            if (coordinates.get(j).getLon360() == coordinates.get(i).getLon360()) {
+                constant[i] = coordinates.get(i).getLat();
+                multiple[i] = 0;
+            } else {
+                constant[i] = coordinates.get(i).getLat()
+                        - (coordinates.get(i).getLon360() * coordinates.get(j).getLat())
+                        / (coordinates.get(j).getLon360() - coordinates.get(i).getLon360())
+                        + (coordinates.get(i).getLon360() * coordinates.get(i).getLat())
+                        / (coordinates.get(j).getLon360() - coordinates.get(i).getLon360());
+                multiple[i] = (coordinates.get(j).getLat() - coordinates.get(i).getLat())
+                        / (coordinates.get(j).getLon360() - coordinates.get(i).getLon360());
+            }
+        }
+    }
+
+    @Override
+    public boolean containsPoint(double latitude, double longitude) {
+
+        int polyCorners = coordinates.size();
+        int i;
+        int j = polyCorners - 1;
+        double longitude360 = longitude + Coordinate.DEGREE360;
+        boolean oddNodes = false;
+
+        for (i = 0; i < polyCorners; j = i++) {
+            if (coordinates.get(i).getLon360() < longitude360
+                && coordinates.get(j).getLon360() >= longitude360
+                || coordinates.get(j).getLon360() < longitude360
+                && coordinates.get(i).getLon360() >= longitude360) {
+                oddNodes ^= longitude360 * multiple[i] + constant[i] < latitude;
+            }
+        }
+        return oddNodes;
+    }
+
+    @Override
+    public String toWKT() {
+        StringBuffer buf = new StringBuffer();
+        buf.append("POLYGON (");
+        for (Coordinate coordinate : coordinates) {
+            buf.append(String.valueOf(coordinate.getLat()));
+            buf.append(" ");
+            buf.append(String.valueOf(coordinate.getLon()));
+            buf.append(", ");
+        }
+        return buf.substring(0, buf.length() - 2) + ")";
+    }
+
+    @Override
+    public void fromWKT(String wkt) throws ParseException {
+        if (coordinates == null) {
+            coordinates = new ArrayList<Coordinate>();
+        } else {
+            coordinates.clear();
+        }
+
+        if (!wkt.startsWith("POLYGON")) {
+            throw new ParseException("Mismatch geometry type", 0);
+        }
+        String content = wkt.substring(wkt.indexOf("(") + 1, wkt.indexOf(")"));
+        if (content == null || content.equals("")) {
+            throw new ParseException("No content", 0);
+        }
+        String[] commatokens = content.split(",");
+        if (commatokens.length < 3) {
+            throw new ParseException("Not valid content", 0);
+        }
+
+        for (String commatoken : commatokens) {
+            String[] tokens = commatoken.trim().split("\\s");
+            if (tokens.length != 2) {
+                throw new ParseException("Here must be two coordinates: " + commatoken, 0);
+            }
+            Coordinate coordinate = new Coordinate();
+            try {
+                coordinate.setLat(Double.parseDouble(tokens[0]));
+            } catch (NumberFormatException e) {
+                throw new ParseException(tokens[0] + " is not a double", 0);
+            }
+            try {
+                coordinate.setLon(Double.parseDouble(tokens[1]));
+            } catch (NumberFormatException e) {
+                throw new ParseException(tokens[1] + " is not a double", 0);
+            }
+            coordinates.add(coordinate);
+        }
+        precalc();
+    }
+
+}