enemy: add alert memory; vision variance based on type

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: I2f5c7cac72c8772e5871b99026d106b46a6a6964

src/common.h

@@ -104,6 +104,11 @@ typedef struct {
   int status_chance;
   int crit_chance;  // crit chance percentage (0-100)
   int crit_mult;    // crit damage multiplier percentage (e.g. 150 = 1.5x)
+  // vision
+  int vision_range;
+  int alert;         // 1 = aware of player, searching
+  int last_known_x;  // last position where enemy saw player
+  int last_known_y;
   // status effects
   StatusEffect effects[MAX_EFFECTS];
   int effect_count;

src/enemy.c

@@ -70,6 +70,7 @@ void enemy_spawn(Enemy enemies[], int *count, Map *map, Player *p, int floor) {
       e.resistance[DMG_PIERCE] = 0;
       e.resistance[DMG_FIRE] = -25;
       e.resistance[DMG_POISON] = 50;
+      e.vision_range = 7;
       break;
     case ENEMY_SKELETON:
       e.max_hp = ENEMY_BASE_HP + floor + 2;
@@ -87,6 +88,7 @@ void enemy_spawn(Enemy enemies[], int *count, Map *map, Player *p, int floor) {
       e.resistance[DMG_PIERCE] = 50;
       e.resistance[DMG_FIRE] = 25;
       e.resistance[DMG_POISON] = 75;
+      e.vision_range = 6;
       break;
     case ENEMY_ORC:
       e.max_hp = ENEMY_BASE_HP + floor + 4;
@@ -104,6 +106,7 @@ void enemy_spawn(Enemy enemies[], int *count, Map *map, Player *p, int floor) {
       e.resistance[DMG_PIERCE] = -25;
       e.resistance[DMG_FIRE] = 0;
       e.resistance[DMG_POISON] = 0;
+      e.vision_range = 5;
       break;
     default:
       e.max_hp = ENEMY_BASE_HP;
@@ -117,6 +120,7 @@ void enemy_spawn(Enemy enemies[], int *count, Map *map, Player *p, int floor) {
       e.crit_chance = ENEMY_CRIT_CHANCE;
       e.crit_mult = ENEMY_CRIT_MULT;
       memset(e.resistance, 0, sizeof(e.resistance));
+      e.vision_range = ENEMY_VIEW_RANGE;
       break;
     }
     e.cooldown = e.speed;
@@ -138,7 +142,7 @@ int is_enemy_at(const Enemy *enemies, int count, int x, int y) {
 
 // Check if enemy can see player (within view range and line of sight)
 static int can_see_player(Enemy *e, Player *p, Map *map) {
-  return can_see_entity(map, e->position.x, e->position.y, p->position.x, p->position.y, ENEMY_VIEW_RANGE);
+  return can_see_entity(map, e->position.x, e->position.y, p->position.x, p->position.y, e->vision_range);
 }
 
 
@@ -190,7 +194,68 @@ static void enemy_patrol(Enemy *e, Map *map, Enemy *all_enemies, int enemy_count
   }
 }
 
-// Perform a single action for an enemy (attack if visible, otherwise patrol)
+// Move enemy toward last known player position
+static void enemy_move_to_last_known(Enemy *e, Map *map, Enemy *all_enemies, int enemy_count) {
+  int dx = 0, dy = 0;
+
+  if (e->last_known_x > e->position.x)
+    dx = 1;
+  else if (e->last_known_x < e->position.x)
+    dx = -1;
+
+  if (e->last_known_y > e->position.y)
+    dy = 1;
+  else if (e->last_known_y < e->position.y)
+    dy = -1;
+
+  int new_x = e->position.x + dx;
+  int new_y = e->position.y;
+
+  if (dx != 0 && is_floor(map, new_x, new_y) && !is_enemy_at(all_enemies, enemy_count, new_x, new_y)) {
+    e->position.x = new_x;
+  } else if (dy != 0) {
+    new_x = e->position.x;
+    new_y = e->position.y + dy;
+    if (is_floor(map, new_x, new_y) && !is_enemy_at(all_enemies, enemy_count, new_x, new_y)) {
+      e->position.x = new_x;
+      e->position.y = new_y;
+    }
+  }
+
+  if (e->position.x == e->last_known_x && e->position.y == e->last_known_y)
+    e->alert = 0;
+}
+
+// Check if position is within alert radius of another enemy
+static int is_nearby_enemy(const Enemy *enemies, int count, int x, int y, int radius) {
+  for (int i = 0; i < count; i++) {
+    if (!enemies[i].alive)
+      continue;
+    int dx = enemies[i].position.x - x;
+    int dy = enemies[i].position.y - y;
+    if (dx * dx + dy * dy <= radius * radius)
+      return 1;
+  }
+  return 0;
+}
+
+// Propagate alert to nearby enemies
+static void propagate_alert(Enemy *trigger_enemy, Enemy *all_enemies, int enemy_count) {
+  for (int i = 0; i < enemy_count; i++) {
+    Enemy *e = &all_enemies[i];
+    if (!e->alive || e == trigger_enemy)
+      continue;
+    if (e->alert)
+      continue;
+    if (is_nearby_enemy(all_enemies, enemy_count, e->position.x, e->position.y, 5)) {
+      e->alert = 1;
+      e->last_known_x = trigger_enemy->last_known_x;
+      e->last_known_y = trigger_enemy->last_known_y;
+    }
+  }
+}
+
+// Perform a single action for an enemy (attack if visible, otherwise patrol or search)
 void enemy_act(Enemy *e, Player *p, Map *map, Enemy *all_enemies, int enemy_count) {
   if (!e->alive)
     return;
@@ -201,19 +266,34 @@ void enemy_act(Enemy *e, Player *p, Map *map, Enemy *all_enemies, int enemy_coun
 
   int can_see = can_see_player(e, p, map);
 
+  // If we can see the player, update alert state and last known position
+  if (can_see) {
+    e->alert = 1;
+    e->last_known_x = p->position.x;
+    e->last_known_y = p->position.y;
+  }
+
   // Attack if adjacent to player
   if (can_see && can_see_entity(map, e->position.x, e->position.y, p->position.x, p->position.y, 1)) {
     combat_enemy_attack(e, p);
+    propagate_alert(e, all_enemies, enemy_count);
     return;
   }
 
   // Move toward player if visible
   if (can_see) {
     enemy_move_toward_player(e, p, map, all_enemies, enemy_count);
+    propagate_alert(e, all_enemies, enemy_count);
     return;
   }
 
-  // Player not visible - patrol randomly
+  // If alert but can't see player, move toward last known position
+  if (e->alert) {
+    enemy_move_to_last_known(e, map, all_enemies, enemy_count);
+    return;
+  }
+
+  // Not alert - patrol randomly
   enemy_patrol(e, map, all_enemies, enemy_count);
 }
 

src/map.c

@@ -12,6 +12,8 @@ void map_init(Map *map) {
       map->tiles[y][x] = TILE_WALL;
     }
   }
+  memset(map->visible, 0, sizeof(map->visible));
+  memset(map->remembered, 0, sizeof(map->remembered));
   map->room_count = 0;
 }