Change new mirrorAngle to mirrorAngleOrigin, improved javadocs.

The old mirrorAngle mirrors around the "y-axis" (PI/2 or -PI/2 as appropriate) which is necessary for other code (particularly angularDifference) to work correctly. The new mirrorAngleOrigin mirrors around the "x-axis" (zero).
2013-02-12 14:24:04 -08:00
parent 0ffabf1419
commit f26a72c26f
2 changed files with 34 additions and 4 deletions
@@ -166,9 +166,20 @@ public class MathUtil
    }

    /**
-     * Returns the mirror angle of the specified angle (assumed to be in [-pi, +pi]).
+     * Returns the mirror angle of the specified angle (assumed to be in [-pi, +pi]). The angle is
+     * mirrored around the PI/2 if it is positive, and -PI/2 if it is negative. One can visualize
+     * this as mirroring around the "y-axis".
     */
    public static float mirrorAngle (float a) {
+        return (a > 0f ? FloatMath.PI : -FloatMath.PI) - a;
+    }
+
+    /**
+     * Returns the mirror angle of the specified angle (assumed to be in [-pi, +pi]). The angle is
+     * mirrored around the origin (zero degrees). One can visualize this as mirroring around the
+     * "x-axis".
+     */
+    public static float mirrorAngleOrigin (float a) {
        return a + (a > 0f ? -FloatMath.PI : FloatMath.PI);
    }