diff --git a/tests/shadowcasting_test.cpp b/tests/shadowcasting_test.cpp
index 3f2fac6f48d55..6ba487bd35791 100644
--- a/tests/shadowcasting_test.cpp
+++ b/tests/shadowcasting_test.cpp
@@ -411,8 +411,10 @@ const tripoint ORIGIN( 65, 65, 11 );
 
 struct grid_overlay {
     std::vector<std::vector<std::vector<float>>> data;
+    std::vector<std::vector<std::vector<bool>>> floor;
     tripoint offset;
     float default_value;
+    bool default_floor = true;
 
     // origin_offset is specified as the coordinates of the "camera" within the overlay.
     grid_overlay( const point origin_offset, const float default_value ) {
@@ -451,6 +453,15 @@ struct grid_overlay {
         }
         return default_value;
     }
+    bool get_floor( const int x, const int y, const int z ) const {
+        if( !floor.empty() &&
+            y >= offset.y && y < offset.y + height() &&
+            x >= offset.x && x < offset.x + width() &&
+            z >= offset.z && z < offset.z + depth() ) {
+            return data[ z - offset.z ][ y - offset.y ][ x - offset.x ];
+        }
+        return default_floor;
+    }
 };
 
 static void run_spot_check( const grid_overlay &test_case, const grid_overlay &expected,
@@ -475,6 +486,7 @@ static void run_spot_check( const grid_overlay &test_case, const grid_overlay &e
         for( int y = 0; y < MAPSIZE * SEEY; ++y ) {
             for( int x = 0; x < MAPSIZE * SEEX; ++x ) {
                 caches[z]->transparency_cache[x][y] = test_case.get_global( x, y, z );
+                caches[z]->floor_cache[x][y] = test_case.get_floor( x, y, z );
             }
         }
     }
@@ -659,6 +671,144 @@ TEST_CASE( "shadowcasting_vision_along_a_wall", "[shadowcasting]" )
     run_spot_check( test_case, expected_results, false );
 }
 
+TEST_CASE( "shadowcasting_edgewise_wall_view", "[shadowcasting]" )
+{
+    grid_overlay test_case( { 1, 2 }, LIGHT_TRANSPARENCY_CLEAR );
+    test_case.data = { {
+            {T, T, O, T, T, T, T},
+            {T, T, O, T, T, T, T},
+            {T, T, O, O, O, T, T},
+            {T, T, T, T, T, T, T},
+            {T, T, T, T, T, T, T}
+        }
+    };
+
+    grid_overlay expected_results( { 1, 2 }, LIGHT_TRANSPARENCY_CLEAR );
+    expected_results.data = { {
+            {V, V, V, O, O, O, O},
+            {V, V, V, O, O, O, O},
+            {V, X, V, O, O, O, O},
+            {V, V, V, V, O, O, O},
+            {V, V, V, V, V, O, O},
+            {V, V, V, V, V, V, O}
+        }
+    };
+
+    run_spot_check( test_case, expected_results, true );
+    run_spot_check( test_case, expected_results, false );
+}
+
+TEST_CASE( "shadowcasting_opaque_floors", "[shadowcasting]" )
+{
+    grid_overlay test_case( { 2, 2, 1 }, LIGHT_TRANSPARENCY_CLEAR );
+    test_case.data = {
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        },
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        },
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        }
+    };
+
+    grid_overlay expected_results( { 2, 2, 1 }, LIGHT_TRANSPARENCY_CLEAR );
+    expected_results.data = {
+        {
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O}
+        },
+        {
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, X, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V}
+        },
+        {
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O},
+            {O, O, O, O, O}
+        }
+    };
+
+    run_spot_check( test_case, expected_results, true );
+}
+
+TEST_CASE( "shadowcasting_transparent_floors", "[shadowcasting]" )
+{
+    grid_overlay test_case( { 2, 2, 1 }, LIGHT_TRANSPARENCY_CLEAR );
+    test_case.data = {
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        },
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        },
+        {
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T},
+            {T, T, T, T, T}
+        }
+    };
+    test_case.default_floor = false;
+
+    grid_overlay expected_results( { 2, 2, 1 }, LIGHT_TRANSPARENCY_CLEAR );
+    expected_results.data = {
+        {
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V}
+        },
+        {
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, X, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V}
+        },
+        {
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V},
+            {V, V, V, V, V}
+        }
+    };
+
+    run_spot_check( test_case, expected_results, true );
+}
+
 // Some random edge cases aren't matching.
 TEST_CASE( "shadowcasting_runoff", "[.]" )
 {