create utility file to store reused math logic, add modal path to config file

app/config.py

@@ -14,6 +14,7 @@ class Config:
     FIREBASE_DATABASE_URL = os.environ.get('FIREBASE_DATABASE_URL')
     
     # Model
+    MODEL_PATH = os.environ.get('MODEL_PATH', 'model_data/checkpoint_best_total.pth')
     CONFIDENCE_THRESHOLD = 0.5
     FRAME_WIDTH = 672
     FRAME_HEIGHT = 448

app/services/processing_service.py

@@ -8,6 +8,8 @@ from app import socketio
 from app.services.video_processor import VideoProcessor
 from app.services.firebase_service import FirebaseService
 from app.models import SessionData
+from app.config import Config
+from app.utils.math_utils import calculate_line_signed_distance
 
 # Global state to track processing jobs
 processing_jobs = {}
@@ -76,7 +78,7 @@ def _process_video_background(job: ProcessingJob):
     
     try:
         # Initialize services
-        video_processor = VideoProcessor(model_path="model_data/checkpoint_best_total.pth")
+        video_processor = VideoProcessor(model_path=Config.MODEL_PATH)
         firebase_service = FirebaseService()
         
         # Create session data
@@ -270,7 +272,7 @@ def _process_frame_detections(detections, line_points, track_class, track_last_d
         lp1 = (int(line_points[0][0]), int(line_points[0][1]))
         lp2 = (int(line_points[1][0]), int(line_points[1][1]))
         
-        dist, is_within = _line_signed_distance(lp1, lp2, (cx, cy))
+        dist, is_within = calculate_line_signed_distance(lp1, lp2, (cx, cy))
         
         prev_data = track_last_dist.get(tracker_id)
         track_class[tracker_id] = int(class_id)
@@ -309,34 +311,6 @@ def _process_frame_detections(detections, line_points, track_class, track_last_d
         
         track_last_dist[tracker_id] = (dist, is_within)
 
-
-def _line_signed_distance(p1, p2, centroid):
-    """Calculate signed distance from point to line"""
-    import math
-    x1, y1 = p1
-    x2, y2 = p2
-    cx, cy = centroid
-    
-    dx = x2 - x1
-    dy = y2 - y1
-    line_len_sq = dx * dx + dy * dy
-    
-    if line_len_sq == 0:
-        return 0.0, False
-    
-    t = ((cx - x1) * dx + (cy - y1) * dy) / line_len_sq
-    margin = 0.1
-    is_within_segment = -margin <= t <= 1.0 + margin
-    
-    a = y2 - y1
-    b = x1 - x2
-    c = x2 * y1 - x1 * y2
-    denom = math.hypot(a, b)
-    signed_dist = (a * cx + b * cy + c) / denom if denom != 0 else 0.0
-    
-    return signed_dist, is_within_segment
-
-
 # SocketIO event emitters
 def _emit_status_update(job: ProcessingJob):
     """Emit job status update"""

app/services/video_processor.py

@@ -9,6 +9,7 @@ from rfdetr import RFDETRBase
 from datetime import datetime
 from app.models import VehicleEvent, SessionData
 from app.config import Config
+from app.utils.math_utils import calculate_line_signed_distance
 
 class VideoProcessor:
     def __init__(self, model_path: str):
@@ -148,7 +149,7 @@ class VideoProcessor:
             # Convert line points to integers
             lp1 = (int(line_points[0][0]), int(line_points[0][1]))
             lp2 = (int(line_points[1][0]), int(line_points[1][1]))
-            dist, is_within = self._line_signed_distance(lp1, lp2, (cx, cy))
+            dist, is_within = calculate_line_signed_distance(lp1, lp2, (cx, cy))
             
             prev_data = track_last_dist.get(tracker_id)
             track_class[tracker_id] = int(class_id)
@@ -179,31 +180,6 @@ class VideoProcessor:
             
             track_last_dist[tracker_id] = (dist, is_within)
     
-    def _line_signed_distance(self, p1, p2, centroid):
-        """Calculate signed distance from point to line"""
-        x1, y1 = p1
-        x2, y2 = p2
-        cx, cy = centroid
-        
-        dx = x2 - x1
-        dy = y2 - y1
-        line_len_sq = dx * dx + dy * dy
-        
-        if line_len_sq == 0:
-            return 0.0, False
-        
-        t = ((cx - x1) * dx + (cy - y1) * dy) / line_len_sq
-        margin = 0.1
-        is_within_segment = -margin <= t <= 1.0 + margin
-        
-        a = y2 - y1
-        b = x1 - x2
-        c = x2 * y1 - x1 * y2
-        denom = math.hypot(a, b)
-        signed_dist = (a * cx + b * cy + c) / denom if denom != 0 else 0.0
-        
-        return signed_dist, is_within_segment
-    
     def _draw_counts(self, frame, session_data):
         """Draw vehicle counts on frame"""
         stats = session_data.get_statistics()

app/utils/math_utils.py

@@ -0,0 +1,29 @@
+import math
+
+def calculate_line_signed_distance(p1, p2, centroid):
+    """
+    Calculate signed distance from point to line.
+    Returns (signed_dist, is_within_segment)
+    """
+    x1, y1 = p1
+    x2, y2 = p2
+    cx, cy = centroid
+    
+    dx = x2 - x1
+    dy = y2 - y1
+    line_len_sq = dx * dx + dy * dy
+    
+    if line_len_sq == 0:
+        return 0.0, False
+    
+    t = ((cx - x1) * dx + (cy - y1) * dy) / line_len_sq
+    margin = 0.1
+    is_within_segment = -margin <= t <= 1.0 + margin
+    
+    a = y2 - y1
+    b = x1 - x2
+    c = x2 * y1 - x1 * y2
+    denom = math.hypot(a, b)
+    signed_dist = (a * cx + b * cy + c) / denom if denom != 0 else 0.0
+    
+    return signed_dist, is_within_segment