fix any raster size except 360x180 didn't actually work :-(

see streetcomplete/StreetComplete@29b0043#commitcomment-112269522

Author: westnordost

README.md

@@ -13,7 +13,7 @@ The default data used is derived from OpenStreetMap and thus © OpenStreetMap co
 
 ## Usage
 
-Add [`de.westnordost:countryboundaries:2.0`](https://mvnrepository.com/artifact/de.westnordost/countryboundaries/2.0) as a Maven dependency or download the jar from there.
+Add [`de.westnordost:countryboundaries:2.1`](https://mvnrepository.com/artifact/de.westnordost/countryboundaries/2.1) as a Maven dependency or download the jar from there.
 
 ```java
 // load data. You should do this once and use CountryBoundaries as a singleton.

library/build.gradle

@@ -4,7 +4,7 @@ plugins {
     id 'signing'
 }
 
-version = "2.0"
+version = "2.1"
 group = "de.westnordost"
 
 dependencies {

library/src/main/java/de/westnordost/countryboundaries/CountryBoundaries.java

@@ -223,13 +223,13 @@ private int latitudeToCellY(double latitude) {
 
 	private int longitudeToLocalX(int cellX, double longitude) {
 		double cellLongitude = -180.0 + 360.0 * cellX / rasterWidth;
-		return (int) ((longitude - cellLongitude) * 360.0 * 0xffff / rasterWidth);
+		return (int) ((longitude - cellLongitude) * rasterWidth * 0xffff / 360.0);
 	}
 
 	private int latitudeToLocalY(int cellY, double latitude) {
 		int rasterHeight = raster.length / rasterWidth;
 		double cellLatitude = +90 - 180.0 * (cellY + 1) / rasterHeight;
-		return (int) ((latitude - cellLatitude) * 180.0 * 0xffff / rasterHeight);
+		return (int) ((latitude - cellLatitude) * rasterHeight * 0xffff / 180.0);
 	}
 
 	private static double normalize(double value, double startAt, double base)

library/src/test/java/de/westnordost/countryboundaries/CountryBoundariesIntegrationTest.java

@@ -61,6 +61,6 @@ public class CountryBoundariesIntegrationTest {
     }
 
     private CountryBoundaries load() throws IOException  {
-        return CountryBoundaries.load(new FileInputStream("../data/boundaries360x180.ser"));
+        return CountryBoundaries.load(new FileInputStream("../data/boundaries180x90.ser"));
     }
 }

sampleapp/src/main/assets/boundaries180x90.ser

@@ -10,8 +10,8 @@
 
 public class GridOverlay extends Overlay {
 
-    public int width = 360;
-    public int height = 180;
+    public int width = 180;
+    public int height = 90;
 
     private final Paint mLinePaint = new Paint();
 

sampleapp/src/main/assets/boundaries360x180.ser

@@ -59,7 +59,7 @@ protected void onCreate(Bundle savedInstanceState)
         try
 		{
 			long t = System.currentTimeMillis();
-			countryBoundaries = CountryBoundaries.load(getAssets().open("boundaries360x180.ser"));
+			countryBoundaries = CountryBoundaries.load(getAssets().open("boundaries180x90.ser"));
 
 			t = System.currentTimeMillis() - t;