From 05c7699937eaeadad94849f7d5a06f32c0c54b88 Mon Sep 17 00:00:00 2001
From: asofold <asofold@web.de>
Date: Sat, 29 Dec 2012 16:47:03 +0100
Subject: [PATCH] Use a defensive method for yaw difference for the angle
 check.

---
 .../nocheatplus/checks/fight/Angle.java       |  4 +++-
 .../nocheatplus/utilities/CheckUtils.java     | 19 ++++++++++++++++++-
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/fight/Angle.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/fight/Angle.java
index 7efb5a56..99a2ccb3 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/fight/Angle.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/checks/fight/Angle.java
@@ -7,6 +7,7 @@ import org.bukkit.entity.Player;
 
 import fr.neatmonster.nocheatplus.checks.Check;
 import fr.neatmonster.nocheatplus.checks.CheckType;
+import fr.neatmonster.nocheatplus.utilities.CheckUtils;
 import fr.neatmonster.nocheatplus.utilities.LagMeasureTask;
 
 /*
@@ -71,6 +72,7 @@ public class Angle extends Check {
 
         // Browse the locations of the map.
         long previousTime = 0L;
+        // TODO: Don't store locations, but yaws ?
         Location previousLocation = null;
         for (final long time : data.angleHits.descendingKeySet()) {
             final Location location = data.angleHits.get(time);
@@ -82,7 +84,7 @@ public class Angle extends Check {
                 // Calculate the time elapsed between the two hits.
                 deltaTime += previousTime - time;
                 // Calculate the difference of the yaw between the two locations.
-                final float dYaw = (previousLocation.getYaw() - location.getYaw()) % 180;
+                final float dYaw = CheckUtils.yawDiff(previousLocation.getYaw(), location.getYaw());
                 deltaYaw += Math.abs(dYaw);
             }
             // Remember the current time and location.
diff --git a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/utilities/CheckUtils.java b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/utilities/CheckUtils.java
index 0b387042..a82b72df 100644
--- a/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/utilities/CheckUtils.java
+++ b/NCPPlugin/src/main/java/fr/neatmonster/nocheatplus/utilities/CheckUtils.java
@@ -16,7 +16,7 @@ import org.bukkit.util.Vector;
 import fr.neatmonster.nocheatplus.NoCheatPlus;
 
 /**
- * Random auxiliary gear, some might have general quality.
+ * Random auxiliary gear, some might have general quality. Contents are likely to get moved to other classes.
  */
 public class CheckUtils {
 
@@ -319,6 +319,23 @@ public class CheckUtils {
 		else return diff;
 	}
 	
+	/**
+	 * Yaw (angle in grad) difference. This ensures inputs are interpreted correctly (for 360 degree offsets).
+	 * @param fromYaw
+	 * @param toYaw
+	 * @return Angle difference to get from fromYaw to toYaw. Result is in [-180, 180].
+	 */
+	public static final float yawDiff(float fromYaw, float toYaw){
+		if (fromYaw <= -360f) fromYaw = -((-fromYaw) % 360f);
+		else if (fromYaw >= 360f) fromYaw = fromYaw % 360f;
+		if (toYaw <= -360f) toYaw = -((-toYaw) % 360f);
+		else if (toYaw >= 360f) toYaw = toYaw % 360f;
+		float yawDiff = toYaw - fromYaw;
+		if (yawDiff < -180f) yawDiff += 360f;
+		else if (yawDiff > 180f) yawDiff -= 360f;
+		return yawDiff;
+	}
+	
 	 /**
 	  * @deprecated Use instead: LogUtil.logSevere
 	  * @param msg