Put angle-related utilities into their own package

Also, use float instead of double for every angle computation.

Conflicts:
	main/src/cgeo/geocaching/ui/CacheListAdapter.java

1 files changed, 28 insertions, 0 deletions

diff --git a/main/src/cgeo/geocaching/utils/AngleUtils.java b/main/src/cgeo/geocaching/utils/AngleUtils.java
new file mode 100644
index 0000000..e2b4a66
--- /dev/null
+++ b/main/src/cgeo/geocaching/utils/AngleUtils.java
@@ -0,0 +1,28 @@
+package cgeo.geocaching.utils;
+
+public class AngleUtils {
+
+    private AngleUtils() {
+        // Do not instantiate
+    }
+
+    /**
+     * Return the angle to turn of to go from an angle to the other
+     *
+     * @param from the origin angle in degrees
+     * @param to the target angle in degreees
+     * @return a value in degrees, in the [-180, 180[ range
+     */
+    public static float difference(final float from, final float to) {
+        return normalize(to - from + 180) - 180;
+    }
+
+    /**
+     * Normalize an angle so that it belongs to the [0, 360[ range.
+     * @param angle the angle in degrees
+     * @return the same angle in the [0, 360[ range
+     */
+    public static float normalize(final float angle) {
+        return (angle >= 0 ? angle : (360 - ((-angle) % 360))) % 360;
+    }
+}