Fix: EntityPositionDeltaPacket.delta_{x,y,z} use wrong format

ammaraskar · Aug 31, 2020 · cf93923 · cf93923
1 parent eae6e5c
commit cf93923
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Showing 2 changed files with 14 additions and 14 deletions.
diff --git a/minecraft/networking/packets/clientbound/play/__init__.py b/minecraft/networking/packets/clientbound/play/__init__.py
@@ -240,14 +240,14 @@ def get_definition(context):
         ]
 
     # The following transforms are retained for backward compatibility;
-    # they represent the delta values as fixed-point integers with 5 bits
+    # they represent the delta values as fixed-point integers with 12 bits
     # of fractional part, regardless of the protocol version.
-    delta_x = attribute_transform('delta_x_float', lambda x: int(x * 32),
-                                                   lambda x: x / 32)
-    delta_y = attribute_transform('delta_y_float', lambda y: int(y * 32),
-                                                   lambda y: y / 32)
-    delta_z = attribute_transform('delta_z_float', lambda z: int(z * 32),
-                                                   lambda z: z / 32)
+    delta_x = attribute_transform(
+                'delta_x_float', lambda x: int(x * 4096), lambda x: x / 4096)
+    delta_y = attribute_transform(
+                'delta_y_float', lambda y: int(y * 4096), lambda y: y / 4096)
+    delta_z = attribute_transform(
+                'delta_z_float', lambda z: int(z * 4096), lambda z: z / 4096)
 
 
 class TimeUpdatePacket(Packet):

diff --git a/tests/test_backward_compatible.py b/tests/test_backward_compatible.py
@@ -163,12 +163,12 @@ def test_join_game_packet(self):
 
     def test_entity_position_delta_packet(self):
         packet = clientbound.play.EntityPositionDeltaPacket()
-        packet.delta_x = -128
+        packet.delta_x = -32768
         packet.delta_y = 33
-        packet.delta_z = 127
-        self.assertEqual(packet.delta_x_float, -4.0)
-        self.assertEqual(packet.delta_y_float, 1.03125)
-        self.assertEqual(packet.delta_z_float, 3.96875)
-        self.assertEqual(packet.delta_x, -128)
+        packet.delta_z = 32767
+        self.assertEqual(packet.delta_x_float, -8.0)
+        self.assertEqual(packet.delta_y_float, 0.008056640625)
+        self.assertEqual(packet.delta_z_float, 7.999755859375)
+        self.assertEqual(packet.delta_x, -32768)
         self.assertEqual(packet.delta_y, 33)
-        self.assertEqual(packet.delta_z, 127)
+        self.assertEqual(packet.delta_z, 32767)