a

4 files changed, 67 insertions, 9 deletions

diff --git a/src/path-search.cpp b/src/path-search.cpp
index cf7d41d5..47ce6f61 100644
--- a/src/path-search.cpp
+++ b/src/path-search.cpp
@@ -176,10 +176,52 @@ auto path_search::make_neighbor_tile_bbox(Vector2i coord, Vector2ub own_size, ro
     return { Vector2(min + shift), Vector2(max + shift) };
 }
 
-Optional<path_search_result>
-path_search::operator()(world& w, object_id own_id,
-                                           global_coords from, Vector2b from_offset, Vector2ub size,
-                                           global_coords to, Vector2b to_offset)
+auto path_search::get_walkable_neighbor_tiles(world& w, global_coords coord, Vector2ub size, object_id own_id) -> neighbors
+{
+    auto ch = chunk_coords_{ coord.chunk(), coord.z() };
+    auto pos = Vector2i(coord.local());
+
+    if (auto [min, max] = make_neighbor_tile_bbox(pos, size, rotation_COUNT);
+        !is_passable(w, ch, min, max, own_id))
+        return {};
+
+    neighbors ns;
+
+    using enum rotation;
+    constexpr struct {
+        Vector2i off;
+        rotation r = {};
+    } nbs[] = {
+        { {  0, -1 }, N },
+        { {  1,  0 }, E },
+        { {  0,  1 }, S },
+        { { -1,  0 }, W },
+    };
+
+    for (auto [off, dir] : nbs)
+    {
+        auto [min, max] = make_neighbor_tile_bbox(pos, size, dir);
+        if (is_passable(w, ch, min, max, own_id))
+            ns.neighbors[ns.size++] = coord + off;
+    }
+
+    return ns;
+}
+
+auto path_search::bbox_union(bbox bb, Vector2i coord, Vector2b offset, Vector2ub size) -> bbox
+{
+    auto center = coord * iTILE_SIZE2 + Vector2i(offset);
+    auto min = center - Vector2i(size / 2u);
+    auto max = center + Vector2i(size);
+    return {
+        .min = Math::min(bb.min, Vector2(min)),
+        .max = Math::max(bb.max, Vector2(max)),
+    };
+}
+
+Optional<path_search_result> path_search::operator()(world& w, object_id own_id,
+                                                     global_coords from, Vector2b from_offset, Vector2ub size,
+                                                     global_coords to, Vector2b to_offset)
 {
     if (from.z() != to.z()) [[unlikely]]
         return {};
diff --git a/src/path-search.hpp b/src/path-search.hpp
index 68cf41a4..4d3c7d23 100644
--- a/src/path-search.hpp
+++ b/src/path-search.hpp
@@ -41,9 +41,9 @@ struct path_search_result final
     const global_coords* data() const;
 
 private:
-    mutable path_search_result* _next;
+    mutable path_search_result* _next = nullptr;
     std::unique_ptr<global_coords[]> _path;
-    size_t _size;
+    size_t _size = 0;
 };
 
 class path_search final
@@ -54,7 +54,7 @@ class path_search final
         auto end() const { return neighbors.data() + size; }
 
         std::array<global_coords, 4> neighbors;
-        uint8_t size;
+        uint8_t size = 0;
     };
 
     struct chunk_tiles_cache
@@ -91,7 +91,8 @@ public:
     static bool is_passable(world& w, global_coords coord, Vector2b offset, Vector2ub size, object_id own_id);
 
     static bbox make_neighbor_tile_bbox(Vector2i coord, Vector2ub own_size, rotation r);
-    static neighbors get_walkable_neighbor_tiles(world& w, global_coords pos, Vector2 size, object_id own_id);
+    static bbox bbox_union(bbox bb, Vector2i coord, Vector2b offset, Vector2ub size);
+    static neighbors get_walkable_neighbor_tiles(world& w, global_coords coord, Vector2ub size, object_id own_id);
 };
 
 } // namespace floormat
diff --git a/src/world.hpp b/src/world.hpp
index bda8d3a4..9b776c5e 100644
--- a/src/world.hpp
+++ b/src/world.hpp
@@ -98,7 +98,7 @@ public:
     [[nodiscard]] object_id make_id() { return ++_object_counter; }
     void set_object_counter(object_id value);
 
-    struct neighbor_pair final { chunk* c; chunk_coords_ coord; };
+    struct neighbor_pair final { chunk* c = nullptr; chunk_coords_ coord; };
 
     std::array<neighbor_pair, 8> neighbors(chunk_coords_ coord);
 
diff --git a/test/path-search.cpp b/test/path-search.cpp
index 3b1c4e93..6fad1fa5 100644
--- a/test/path-search.cpp
+++ b/test/path-search.cpp
@@ -23,6 +23,10 @@ void test_bbox()
         return path_search::make_neighbor_tile_bbox(coord, {}, r);
     };
 
+    constexpr auto neighbor_tiles = [](world& w, chunk_coords_ ch, Vector2i pos) {
+        return path_search::get_walkable_neighbor_tiles(w, {ch, pos}, {}, (object_id)-1);
+    };
+
     const auto metal2 = loader.tile_atlas("metal2", {2, 2}, pass_mode::blocked);
     const auto table  = loader.scenery("table1");
 
@@ -61,19 +65,25 @@ void test_bbox()
         fm_assert(  is_passable_1(c, bbox({8, 6}, N)) );
         fm_assert( !is_passable_1(c, bbox({8, 6}, S)) );
         fm_assert( !is_passable_1(c, bbox({8, 7}, N)) );
+
         fm_assert(  is_passable_1(c, bbox({8, 8}, N)) );
         fm_assert(  is_passable_1(c, bbox({8, 8}, E)) );
         fm_assert( !is_passable_1(c, bbox({8, 8}, S)) );
         fm_assert(  is_passable_1(c, bbox({8, 8}, W)) );
 
+        fm_assert(neighbor_tiles(w, ch, {8, 8}).size == 3);
+
         c[{8, 8}].wall_north() = {metal2,0};
         c.mark_passability_modified();
         fm_assert(  is_passable_1(c, bbox({8, 8}, C)));
         fm_assert( !is_passable_1(c, bbox({8, 7}, S)) );
+
         fm_assert( !is_passable_1(c, bbox({8, 8}, N)) );
         fm_assert(  is_passable_1(c, bbox({8, 8}, E)) );
         fm_assert( !is_passable_1(c, bbox({8, 8}, S)) );
         fm_assert(  is_passable_1(c, bbox({8, 8}, W)) );
+
+        fm_assert(neighbor_tiles(w, ch, {8, 8}).size == 2);
     }
     {
         using enum rotation;
@@ -92,6 +102,11 @@ void test_bbox()
         is_passable_NESW(c, {8, 9}, { false, true,  true,  true  });
         is_passable_NESW(c, {2, 4}, { true,  false, true,  true  });
         is_passable_NESW(c, {4, 4}, { true,  true,  true,  false });
+
+        fm_assert(neighbor_tiles(w, ch, {8, 8}).size == 0);
+        fm_assert(neighbor_tiles(w, ch, {8, 9}).size == 3);
+        fm_assert(neighbor_tiles(w, ch, {2, 4}).size == 3);
+        fm_assert(neighbor_tiles(w, ch, {4, 4}).size == 3);
     }
 }