SurvivalFly: reduce false positives by using an adapted bounding box

for the y-inconsistency case.

src/fr/neatmonster/nocheatplus/checks/moving/MovingData.java

@@ -84,6 +84,8 @@ public class MovingData extends ACheckData {
     public double         verticalFreedom;
     public double         verticalVelocity;
     public int            verticalVelocityCounter;
+    /** Last to coordinates. */
+    public double         fromX, fromY, fromZ, toY;
 
     // Data of the creative check.
     public boolean        creativeFlyPreviousRefused;
@@ -114,7 +116,7 @@ public class MovingData extends ACheckData {
 
     // Data of the survival fly check.
     public int            survivalFlyJumpPhase;
-    public double         survivalFlyLastFromY;
+//    public double         survivalFlyLastFromY;
     /** Last valid y distance covered by a move. Integer.MAX_VALUE indicates "not set". */
     public double         survivalFlyLastYDist = Integer.MAX_VALUE;
     public int            survivalFlyOnIce;
@@ -143,6 +145,7 @@ public class MovingData extends ACheckData {
         survivalFlyJumpPhase = 0;
         setBack = null;
         survivalFlyLastYDist = Integer.MAX_VALUE;
+        fromX = Double.MAX_VALUE;
         clearAccounting();
         clearNoFallData();
     }

src/fr/neatmonster/nocheatplus/checks/moving/MovingListener.java

@@ -358,7 +358,6 @@ public class MovingListener implements Listener {
         
         if (pFrom.isOnGround()){
             data.ground = from; // pFrom.getLocation();
-            data.survivalFlyLastFromY = Integer.MAX_VALUE;
         }
         
 

src/fr/neatmonster/nocheatplus/checks/moving/SurvivalFly.java

@@ -110,21 +110,34 @@ public class SurvivalFly extends Check {
         if (data.setBack == null)
             data.setBack = from.getLocation();
         
+        boolean resetFrom = fromOnGround || from.isInLiquid() || from.isOnLadder() || from.isInWeb();
+        
         final double setBackYDistance = to.getY() - data.setBack.getY();
         // If the player has touched the ground but it hasn't been noticed by the plugin, the workaround is here.
-        if (!fromOnGround && !from.isInWeb()){
+        if (!resetFrom){
-            // TODO: more precise 
+            // TODO: check versus last to position ?
-            // TODO: account for all near ground positions, use as fallback some counter if player.getLocation.getY is < from.getY
-//            final boolean inconsistent = from.getY() < data.survivalFlyLastFromY && yDistance > 0D && yDistance < 0.5D
-//                    && setBackYDistance > 0D && setBackYDistance <= 1.5D 
-//                    && !BlockProperties.isPassable(from.getTypeIdBelow());
-                    
             final boolean inconsistent = yDistance > 0 && yDistance < 0.5 && data.survivalFlyLastYDist < 0 
-                    && setBackYDistance > 0D && setBackYDistance <= 1.5D 
+                    && setBackYDistance > 0D && setBackYDistance <= 1.5D;
-                    && !BlockProperties.isPassable(from.getTypeIdBelow());
+            boolean useWorkaround = from.isAboveStairs();
-            // TODO: Use bounding box ?
+            if (inconsistent){
-            // TODO: fromAboveStairs ?
+                if (cc.debug) System.out.println(player.getName() + " Y-INCONSISTENCY");
-            if (inconsistent || from.isAboveStairs()){ // !toOnGround && to.isAboveStairs()) {
+                if (!useWorkaround && data.fromX != Double.MAX_VALUE){
+                    // Interpolate from last to-coordinates to the from coordinates (with some safe-guard).
+                    final double dX = from.getX() - data.fromX;
+                    final double dY = from.getY() - data.fromY;
+                    final double dZ = from.getZ() - data.fromZ;
+                    if (dX * dX + dY * dY + dZ * dZ < 0.5){ // TODO: adjust limit maybe.
+                        // Check full bounding box since last from.
+                        if (cc.debug) System.out.println(player.getName() + " CONSIDER WORKAROUND");
+                        final double minY = Math.min(data.toY, Math.min(data.fromY, from.getY()));
+                        final double iY =  minY; // TODO ...
+                        final double r = from.getWidth() / 2.0;
+                        useWorkaround = BlockProperties.isOnGround(from.getBlockAccess(), Math.min(data.fromX, from.getX()) - r, iY - cc.yOnGround, Math.min(data.fromZ, from.getZ()) - r, Math.max(data.fromX, from.getX()) + r, iY + 0.25, Math.max(data.fromZ, from.getZ()) + r);
+
+                    }
+                }  
+            }
+            if (useWorkaround){ // !toOnGround && to.isAboveStairs()) {
                 // Set the new setBack and reset the jumpPhase.
                 
                 // Maybe don't adapt the setback (unless null)!
@@ -136,6 +149,7 @@ public class SurvivalFly extends Check {
                 data.clearAccounting();
                 // Tell NoFall that we assume the player to have been on ground somehow.
                 data.noFallAssumeGround = true;
+                resetFrom = true;
                 if (cc.debug) System.out.println(player.getName() + " Y-INCONSISTENCY WORKAROUND USED");
             }
         }
@@ -264,7 +278,6 @@ public class SurvivalFly extends Check {
         			data.setBack.setYaw(to.getYaw());
         			data.setBack.setPitch(to.getPitch());
         			data.survivalFlyLastYDist = Integer.MAX_VALUE;
-        			data.survivalFlyLastFromY = data.setBack.getY();
         			return data.setBack;
         		}
         	}
@@ -289,8 +302,6 @@ public class SurvivalFly extends Check {
         if (data.noFallAssumeGround || fromOnGround || toOnGround)
             data.jumpAmplifier = 0D;
         
-        final boolean resetFrom = data.noFallAssumeGround || fromOnGround || from.isInLiquid() || from.isOnLadder() || from.isInWeb();
-        
         if (cc.survivalFlyAccounting && !resetFrom){
             final boolean useH = data.horizontalFreedom <= 0.001D;
             final boolean useV = data.verticalFreedom <= 0.001D;
@@ -349,7 +360,6 @@ public class SurvivalFly extends Check {
             }
             if (executeActions(vd)){
                 data.survivalFlyLastYDist = Integer.MAX_VALUE;
-                data.survivalFlyLastFromY = data.setBack.getY();
                 // Compose a new location based on coordinates of "newTo" and viewing direction of "event.getTo()" to
                 // allow the player to look somewhere else despite getting pulled back by NoCheatPlus.
                 return new Location(player.getWorld(), data.setBack.getX(), data.setBack.getY(), data.setBack.getZ(),
@@ -371,7 +381,10 @@ public class SurvivalFly extends Check {
             data.clearAccounting();
         }
         data.survivalFlyLastYDist = yDistance;
-        data.survivalFlyLastFromY = from.getY();
+        data.fromX = from.getX();
+        data.fromY = from.getY();
+        data.fromZ = from.getZ();
+        data.toY = to.getY();
         return null;
     }
     

src/fr/neatmonster/nocheatplus/utilities/PlayerLocation.java

@@ -500,5 +500,9 @@ public class PlayerLocation {
     public Vector getVector() {
         return new Vector(x, y, z);
     }
+    
+    public double getWidth(){
+        return entity.width;
+    }
 
 }