Created Mercator projection to convert between Geo location and planar projection point.

- MapGeo and MapPoint encapsulate geo location and planar projection point into classes.

#story[928]

src/main/java/seng302/models/map/Boundary.java

@@ -1,17 +1,17 @@
 package seng302.models.map;
 
 /**
- * The Bound class is to represent square territorial bounds on a map. It contains
+ * The Boundary class represents a square territorial bound on a map. It contains
  * four extremity double values(N, E, S, W). N and S are represented as latitudes
  * in radians. E and W are represented as longitudes in radians.
  *
  * Created by Haoming on 10/5/17
  */
-public class Bound {
+public class Boundary {
 
 	private double north, east, south, west;
 
-	public Bound(double north, double east, double south, double west) {
+	public Boundary(double north, double east, double south, double west) {
 		this.north = north;
 		this.east = east;
 		this.south = south;

src/main/java/seng302/models/map/CanvasMap.java

@@ -2,28 +2,27 @@ package seng302.models.map;
 
 import javafx.scene.image.Image;
 
-import javax.imageio.ImageIO;
 import javax.net.ssl.HttpsURLConnection;
-import java.awt.image.BufferedImage;
-import java.io.BufferedReader;
-import java.io.InputStreamReader;
 import java.net.URL;
 
+import java.lang.Math;
+
 public class CanvasMap {
 
-	private Bound bound;
+	private Boundary bound;
 	private double width, height;  // desired image size
 	private int zoom;
+
+	private int MERCATOR_RANGE = 256;
 	private String KEY = "AIzaSyC-5oOShMCY5Oy_9L7guYMPUPFHDMr37wE";
 
-	public CanvasMap(Bound bound, double width, double height) {
+	public CanvasMap(Boundary bound, double width, double height) {
 		this.bound = bound;
 		this.width = width;
 		this.height = height;
 	}
 
 	public Image getMapImage() {
-
 		try {
 			System.out.println(getRequest());
 			URL url = new URL(getRequest());
@@ -37,13 +36,14 @@ public class CanvasMap {
 	}
 
 	private String getRequest() {
-		zoom = 14;
+		zoom = 15;
 		StringBuilder sb = new StringBuilder();
 		sb.append("https://maps.googleapis.com/maps/api/staticmap?");
 		sb.append(String.format("center=%f,%f", bound.getCentreLat(), bound.getCentreLng()));
 		sb.append(String.format("&zoom=%d", zoom));
 		sb.append(String.format("&size=%.0fx%.0f&scale=2", width / 2, height / 2));
-		sb.append(String.format("&key=%s", KEY));
+		sb.append("&style=feature:all|element:labels|visibility:off"); // hide all labels on map
+//		sb.append(String.format("&key=%s", KEY));
 		return sb.toString();
 	}
 }

src/main/java/seng302/models/map/MapGeo.java

@@ -0,0 +1,27 @@
+package seng302.models.map;
+
+class MapGeo {
+
+	private double lat, lng;
+
+	MapGeo(double lat, double lng) {
+		this.lat = lat;
+		this.lng = lng;
+	}
+
+	double getLat() {
+		return lat;
+	}
+
+	void setLat(double lat) {
+		this.lat = lat;
+	}
+
+	double getLng() {
+		return lng;
+	}
+
+	void setLng(double lng) {
+		this.lng = lng;
+	}
+}

src/main/java/seng302/models/map/MapPoint.java

@@ -0,0 +1,27 @@
+package seng302.models.map;
+
+class MapPoint {
+
+	private double x, y;
+
+	MapPoint(double x, double y) {
+		this.x = x;
+		this.y = y;
+	}
+
+	double getX() {
+		return x;
+	}
+
+	void setX(double x) {
+		this.x = x;
+	}
+
+	double getY() {
+		return y;
+	}
+
+	void setY(double y) {
+		this.y = y;
+	}
+}

src/main/java/seng302/models/map/MercatorProjection.java

@@ -0,0 +1,52 @@
+package seng302.models.map;
+
+public class MercatorProjection {
+
+	private double MERCATOR_RANGE = 256;
+	private double pixelsPerLngDegree, pixelsPerLngRadian;
+
+
+	public MercatorProjection() {
+		pixelsPerLngDegree = MERCATOR_RANGE / 360.0;
+		pixelsPerLngRadian = MERCATOR_RANGE / (2 * Math.PI);
+	}
+
+	/**
+	 * A help function keeps the value in bound between -0.9999 and 0.9999.
+	 * @param value in bound value
+	 * @return the value in bound
+	 */
+	private double bound(double value) {
+		return Math.min(Math.max(value, -0.9999), 0.9999);
+	}
+
+	/**
+	 * Projects a Geo Location (lat, lng) on a planar
+	 * @param geo MapGeo (lat, lng) location to be projected
+	 * @return the projection GeoPoint (x, y) on planar
+	 */
+	public MapPoint toMapPoint(MapGeo geo) {
+		MapPoint point = new MapPoint(0, 0);
+		MapPoint origin = new MapPoint(MERCATOR_RANGE / 2.0, MERCATOR_RANGE / 2.0);
+		point.setX(origin.getX() + geo.getLng() * pixelsPerLngDegree);
+
+//		NOTE(appleton): Truncating to 0.9999 effectively limits latitude to
+//      89.189.  This is about a third of a tile past the edge of the world tile.
+		double sinY = bound(Math.sin(Math.toRadians(geo.getLat())));
+		point.setY(origin.getY() + 0.5 * Math.log((1 + sinY) / (1 - sinY)) * (-pixelsPerLngRadian));
+		return point;
+	}
+
+	/**
+	 * Converts the planar projection (x, y) back to Geo Location (lat, lng)
+	 * @param point MapPoint (x, y) to be converted back
+	 * @return the original Geo location converted from the given projection point
+	 */
+	public MapGeo toMapGeo(MapPoint point) {
+		MapPoint origin = new MapPoint(MERCATOR_RANGE / 2.0, MERCATOR_RANGE / 2.0);
+		double lng = (point.getX() - origin.getX()) / pixelsPerLngDegree;
+		double latRadians = (point.getY() - origin.getY()) / (-pixelsPerLngRadian);
+		double lat = Math.toDegrees(2 * Math.atan(Math.exp(latRadians)) - Math.PI / 2.0);
+		return new MapGeo(lat, lng);
+	}
+}

src/main/java/seng302/models/map/TestMapController.java

@@ -16,7 +16,7 @@ public class TestMapController implements Initializable{
 	@Override
 	public void initialize(URL location, ResourceBundle resources) {
 		GraphicsContext gc = mapCanvas.getGraphicsContext2D();
-		Bound bound = new Bound(57.662943, 11.848501, 57.673945, 11.824966);
+		Boundary bound = new Boundary(57.662943, 11.848501, 57.673945, 11.824966);
 		CanvasMap canvasMap = new CanvasMap(bound, 1280, 960);
 		gc.drawImage(canvasMap.getMapImage(), 0, 0, 1280, 960);
 	}