fix coordinate system interpretation

Author: NicoleFaye

pyboy/plugins/game_wrapper_pokemon_pinball.pxd

@@ -10,10 +10,10 @@ cdef class GameWrapperPokemonPinball(PyBoyGameWrapper):
     cdef readonly int ball_saver_seconds_left
     cdef readonly int ball_size
     cdef readonly int ball_type
-    cdef readonly int ball_x
-    cdef readonly int ball_x_velocity
-    cdef readonly int ball_y
-    cdef readonly int ball_y_velocity
+    cdef readonly float ball_x
+    cdef readonly float ball_x_velocity
+    cdef readonly float ball_y
+    cdef readonly float ball_y_velocity
     cdef readonly int balls_left
     cdef readonly int current_map
     cdef readonly int current_stage

pyboy/plugins/game_wrapper_pokemon_pinball.py

@@ -12,7 +12,7 @@
 import logging
 from enum import Enum
 
-from pyboy.utils import PyBoyException, WindowEvent, bcd_to_dec
+from pyboy.utils import PyBoyException, WindowEvent, bcd_to_dec, fixed_point_to_value
 
 from .base_plugin import PyBoyGameWrapper
 
@@ -695,11 +695,28 @@ def post_tick(self):
         self.multiplier = self.pyboy.memory[ADDR_MULTIPLIER]
 
         self.ball_size = self.pyboy.memory[ADDR_BALL_SIZE]
-
-        self.ball_x = self.pyboy.memory[ADDR_BALL_X]
-        self.ball_y = self.pyboy.memory[ADDR_BALL_Y]
-        self.ball_x_velocity = self.pyboy.memory[ADDR_BALL_X_VELOCITY]
-        self.ball_y_velocity = self.pyboy.memory[ADDR_BALL_Y_VELOCITY]
+        self.ball_x = fixed_point_to_value(
+            self.pyboy.memory[ADDR_BALL_X:ADDR_BALL_X+2], 
+            num_bytes=2,
+            is_signed=True
+        )
+        self.ball_y = fixed_point_to_value(
+            self.pyboy.memory[ADDR_BALL_Y:ADDR_BALL_Y+2], 
+            num_bytes=2,
+            is_signed=True
+        )
+    
+        # Velocity values (likely signed since they can be negative)
+        self.ball_x_velocity = fixed_point_to_value(
+            self.pyboy.memory[ADDR_BALL_X_VELOCITY:ADDR_BALL_X_VELOCITY+2], 
+            num_bytes=2,
+            is_signed=True
+        )
+        self.ball_y_velocity = fixed_point_to_value(
+            self.pyboy.memory[ADDR_BALL_Y_VELOCITY:ADDR_BALL_Y_VELOCITY+2], 
+            num_bytes=2,
+            is_signed=True
+        )
 
         self.pikachu_saver_charge = self.pyboy.memory[ADDR_PIKACHU_SAVER_CHARGE]
 

pyboy/utils.py

@@ -488,3 +488,36 @@ def bcd_to_dec(value, byte_width=1, byteorder="little"):
         multiplier *= 100
 
     return decimal_value
+
+def fixed_point_to_value(raw_bytes, num_bytes=2, is_signed=False, fractional_bits=8):
+    """
+    Convert fixed-point bytes to appropriate value
+    
+    Args:
+        raw_bytes: Byte array containing the fixed-point value
+        num_bytes: Number of bytes in the value (default: 2 for 16-bit)
+        is_signed: Whether to interpret as signed (two's complement)
+        fractional_bits: Number of bits used for the fractional part
+    
+    Returns:
+        A float value representing the fixed-point number
+    """
+    value = int.from_bytes(raw_bytes, "little")
+    
+    total_bits = num_bytes * 8
+    
+    # Calculate integer and fractional parts
+    integer_part = value >> fractional_bits
+    fractional_part = value & ((1 << fractional_bits) - 1)
+    
+    # Handle two's complement for signed values
+    if is_signed and (value & (1 << (total_bits - 1))):
+        # It's a negative value in two's complement
+        # Calculate the negative value properly
+        integer_value = value
+        if integer_value & (1 << (total_bits - 1)):
+            integer_value = -((~integer_value + 1) & ((1 << total_bits) - 1))
+        return integer_value / (1 << fractional_bits)
+    
+    # Return the full fixed-point value
+    return integer_part + (fractional_part / (1 << fractional_bits))