Use occupancy fast path for adjacent enemies (#8792)

src/main/cpp/net/eagle0/shardok/library/commands/MoveCommand.cpp

@@ -57,7 +57,7 @@ auto shardok::MoveCommand::InternalExecute(
         const auto* destinationTerrain = GetTerrain(map, destination);
         bool startedInEnemyZoc = enemyZocCoords.Contains(origin);
         vector<const Unit*> knownAdjacentEnemies =
-                KnownAdjacentEnemies(player, allUnits, map, allyPids, origin);
+                KnownAdjacentEnemies(player, currentState, allyPids, origin);
 
         MutatingSpendActionPoints(
                 &mover,
@@ -132,7 +132,7 @@ auto shardok::MoveCommand::InternalExecute(
 
             if (!startedInEnemyZoc) {
                 vector<const Unit*> newAdjacentEnemies =
-                        KnownAdjacentEnemies(player, allUnits, map, allyPids, destination);
+                        KnownAdjacentEnemies(player, currentState, allyPids, destination);
 
                 for (const Unit* possibleChargee : newAdjacentEnemies) {
                     if (std::ranges::find_if(

src/main/cpp/net/eagle0/shardok/library/util/BUILD.bazel

@@ -42,6 +42,7 @@ cc_library(
     deps = [
         ":hex_cube_utils",
         "//src/main/cpp/net/eagle0/common:filesystem_utils",
+        "//src/main/cpp/net/eagle0/shardok/library:game_state_w",
         "//src/main/cpp/net/eagle0/shardok/library/map:coordinates",
         "//src/main/cpp/net/eagle0/shardok/library/map:coords_set",
         "//src/main/cpp/net/eagle0/shardok/library/map:hex_map_direction",

src/main/cpp/net/eagle0/shardok/library/util/HexMapUtils.cpp

@@ -15,6 +15,7 @@
 
 #include "HexCubeUtils.hpp"
 #include "src/main/cpp/net/eagle0/common/FilesystemUtils.hpp"
+#include "src/main/cpp/net/eagle0/shardok/library/GameStateW.hpp"
 #include "src/main/cpp/net/eagle0/shardok/library/map/CoordsSet.hpp"
 
 namespace shardok {
@@ -694,6 +695,25 @@ auto KnownAdjacentEnemies(
     return knownAdjacentEnemies;
 }
 
+auto KnownAdjacentEnemies(
+        const PlayerId playerId,
+        const GameStateW &gameState,
+        const std::vector<PlayerId> &allyPids,
+        const Coords &coords) -> std::vector<const Unit *> {
+    const CoordsSet &adjacentCoords = HexMapUtils::GetAdjacentCoords(gameState->hex_map(), coords);
+    std::vector<const Unit *> knownAdjacentEnemies{};
+    knownAdjacentEnemies.reserve(adjacentCoords.size());
+
+    for (const Coords &adjCoords : adjacentCoords) {
+        if (const auto *possibleEnemy =
+                    gameState.GetKnownEnemyOccupant(playerId, allyPids, adjCoords)) {
+            knownAdjacentEnemies.push_back(possibleEnemy);
+        }
+    }
+
+    return knownAdjacentEnemies;
+}
+
 auto KnownEnemyOccupant(
         const PlayerId playerId,
         const Units *units,

src/main/cpp/net/eagle0/shardok/library/util/HexMapUtils.hpp

@@ -22,6 +22,8 @@
 #include "src/main/protobuf/net/eagle0/shardok/api/unit_view.pb.h"
 
 namespace shardok {
+class GameStateW;
+
 using Coords = net::eagle0::shardok::storage::fb::Coords;
 using HexMap = net::eagle0::shardok::storage::fb::HexMap;
 using HexMapT = net::eagle0::shardok::storage::fb::HexMapT;
@@ -288,6 +290,12 @@ template<class UnitContainer>
         const std::vector<PlayerId> &allyPids,
         const Coords &coords) -> std::vector<const Unit *>;
 
+[[nodiscard]] auto KnownAdjacentEnemies(
+        PlayerId playerId,
+        const GameStateW &gameState,
+        const std::vector<PlayerId> &allyPids,
+        const Coords &coords) -> std::vector<const Unit *>;
+
 [[nodiscard]] auto DirectionsTo(int columnCount, const Coords &origin, const Coords &destination)
         -> HexMapDirectionsTo;