diff --git a/squirrelbattle/interfaces.py b/squirrelbattle/interfaces.py
index 30e59f4..c1c224f 100644
--- a/squirrelbattle/interfaces.py
+++ b/squirrelbattle/interfaces.py
@@ -206,15 +206,12 @@ class Map:
         else:
             top_y = ceil(((x * 2 - 1) * top.Y + top.X) / (top.X * 2))
             if self.is_wall(top_y, x, octant, origin):
-                if top >= Slope(top_y * 2 + 1, x * 2) and not\
-                        self.is_wall(top_y + 1, x, octant, origin):
-                    top_y += 1
+                top_y += top >= Slope(top_y * 2 + 1, x * 2) and not \
+                    self.is_wall(top_y + 1, x, octant, origin)
             else:
                 ax = x * 2
-                if self.is_wall(top_y + 1, x + 1, octant, origin):
-                    ax += 1
-                if top > Slope(top_y * 2 + 1, ax):
-                    top_y += 1
+                ax += self.is_wall(top_y + 1, x + 1, octant, origin)
+                top_y += top > Slope(top_y * 2 + 1, ax)
         return top_y
 
     def crop_bottom_visibility(self, octant: int, origin: Tuple[int, int],
@@ -224,10 +221,9 @@ class Map:
         else:
             bottom_y = ceil(((x * 2 - 1) * bottom.Y + bottom.X)
                             / (bottom.X * 2))
-            if bottom >= Slope(bottom_y * 2 + 1, x * 2) and\
-                    self.is_wall(bottom_y, x, octant, origin) and\
-                    not self.is_wall(bottom_y + 1, x, octant, origin):
-                bottom_y += 1
+            bottom_y += bottom >= Slope(bottom_y * 2 + 1, x * 2) and \
+                self.is_wall(bottom_y, x, octant, origin) and \
+                not self.is_wall(bottom_y + 1, x, octant, origin)
         return bottom_y
 
     def compute_visibility_octant(self, octant: int, origin: Tuple[int, int],
@@ -254,8 +250,7 @@ class Map:
                     continue
                 if is_opaque and was_opaque == 0:
                     nx, ny = x * 2, y * 2 + 1
-                    if self.is_wall(y + 1, x, octant, origin):
-                        nx -= 1
+                    nx -= self.is_wall(y + 1, x, octant, origin)
                     if top > Slope(ny, nx):
                         if y == bottom_y:
                             bottom = Slope(ny, nx)
@@ -264,14 +259,12 @@ class Map:
                             self.compute_visibility_octant(
                                 octant, origin, max_range, x + 1, top,
                                 Slope(ny, nx))
-                    else:
-                        if y == bottom_y:
-                            return
+                    elif y == bottom_y:  # pragma: no cover
+                        return
                 elif not is_opaque and was_opaque == 1:
                     nx, ny = x * 2, y * 2 + 1
-                    if self.is_wall(y + 1, x + 1, octant, origin):
-                        nx += 1
-                    if bottom >= Slope(ny, nx):
+                    nx += self.is_wall(y + 1, x + 1, octant, origin)
+                    if bottom >= Slope(ny, nx):  # pragma: no cover
                         return
                     top = Slope(ny, nx)
                 was_opaque = is_opaque