diff --git a/physics_engine.vhd b/physics_engine.vhd
index 821e991..faf1b29 100644
--- a/physics_engine.vhd
+++ b/physics_engine.vhd
@@ -301,18 +301,17 @@ begin
             c_top   := py - SIZE11;
             c_bot   := py + SIZE11;
 
-            -- Swept horizontal overlap: union of prev and new extents along motion axis
+            -- Swept overlap: edge-crossing checks (prev and new extents straddle the face)
             if vx(9) = '0' then
-                x_overlap := (c_right >= OBS_L(obs_i)) and (c_prev_left <= OBS_R(obs_i));
+                x_overlap := (c_right >= OBS_L(obs_i)) and (c_prev_right <= OBS_L(obs_i));
             else
-                x_overlap := (c_prev_right >= OBS_L(obs_i)) and (c_left <= OBS_R(obs_i));
+                x_overlap := (c_left <= OBS_R(obs_i)) and (c_prev_left >= OBS_R(obs_i));
             end if;
 
-            -- Swept vertical overlap
             if vy(9) = '0' then
-                y_overlap := (c_bot >= OBS_T(obs_i)) and (c_prev_top <= OBS_B(obs_i));
+                y_overlap := (c_bot >= OBS_T(obs_i)) and (c_prev_bot <= OBS_T(obs_i));
             else
-                y_overlap := (c_prev_bot >= OBS_T(obs_i)) and (c_top <= OBS_B(obs_i));
+                y_overlap := (c_top <= OBS_B(obs_i)) and (c_prev_top >= OBS_B(obs_i));
             end if;
 
             if x_overlap and y_overlap then
diff --git a/renderer.vhd b/renderer.vhd
index 3d51f40..6a9aeba 100644
--- a/renderer.vhd
+++ b/renderer.vhd
@@ -26,8 +26,6 @@ entity renderer is
         char_height  : in  std_logic_vector(9 downto 0);
         cam_x        : in  std_logic_vector(10 downto 0);
         cam_y        : in  std_logic_vector(10 downto 0);
-        vel_x_in     : in  std_logic_vector(9 downto 0);
-        vel_y_in     : in  std_logic_vector(9 downto 0);
         trail_on_in  : in  std_logic;
         red          : out std_logic;
         green        : out std_logic;
@@ -48,7 +46,6 @@ architecture behavior of renderer is
     signal wr : std_logic_vector(10 downto 0);
 
     signal char_on, ground_on, wall_on, ceiling_on, obs_on : std_logic;
-    signal arrow_on : std_logic := '0';  -- disabled
 
 begin
 
@@ -90,17 +87,12 @@ begin
 
     end process render;
 
-    -- Velocity vector arrow disabled — arrow_on held '0' by signal initializer
-
     -- ----------------------------------------------------------------
     -- Color output with priority
     -- ----------------------------------------------------------------
-    color : process(char_on, ground_on, wall_on, ceiling_on,
-                    obs_on, arrow_on, trail_on_in)
+    color : process(char_on, ground_on, wall_on, ceiling_on, obs_on, trail_on_in)
     begin
-        if    arrow_on = '1' then
-            red <= '1'; green <= '1'; blue <= '1';  -- White
-        elsif char_on = '1' then
+        if    char_on = '1' then
             red <= '1'; green <= '0'; blue <= '0';  -- Red
         elsif obs_on = '1' then
             red <= '1'; green <= '1'; blue <= '0';  -- Yellow
diff --git a/visualizer.py b/visualizer.py
index 117c8b4..e2cef85 100644
--- a/visualizer.py
+++ b/visualizer.py
@@ -249,13 +249,13 @@ def main():
             c_top  = py - SIZE;  c_bot   = py + SIZE
 
             if to_signed(vx) >= 0:
-                x_overlap = c_right >= ol and prev_left <= orr
+                x_overlap = c_right >= ol and prev_right <= ol
             else:
-                x_overlap = prev_right >= ol and c_left <= orr
+                x_overlap = c_left <= orr and prev_left >= orr
             if to_signed(vy) >= 0:
-                y_overlap = c_bot >= ot and prev_top <= ob
+                y_overlap = c_bot >= ot and prev_bot <= ot
             else:
-                y_overlap = prev_bot >= ot and c_top <= ob
+                y_overlap = c_top <= ob and prev_top >= ob
 
             if x_overlap and y_overlap:
                 if prev_bot <= ot: