enemy: add alert memory; vision variance based on type

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

src/common.h

@@ -30,6 +30,8 @@ typedef struct {
   TileType tiles[MAP_HEIGHT][MAP_WIDTH];
   Room rooms[MAX_ROOMS];
   int room_count;
+  unsigned char visible[MAP_HEIGHT][MAP_WIDTH];
+  unsigned char remembered[MAP_HEIGHT][MAP_WIDTH];
 } Map;
 
 // Dungeon
@@ -98,6 +100,11 @@ 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

@@ -3,6 +3,7 @@
 #include "common.h"
 #include "map.h"
 #include "rng.h"
+#include "settings.h"
 #include <string.h>
 
 // Forward declaration
@@ -68,6 +69,7 @@ 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;
@@ -85,6 +87,7 @@ 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;
@@ -102,6 +105,7 @@ 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;
@@ -115,6 +119,7 @@ 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;
@@ -134,11 +139,9 @@ int is_enemy_at(const Enemy *enemies, int count, int x, int y) {
   return 0;
 }
 
-// Check if enemy can see player (adjacent)
-static int can_see_player(Enemy *e, Player *p) {
-  int dx = p->x - e->x;
-  int dy = p->y - e->y;
-  return (dx >= -1 && dx <= 1 && dy >= -1 && dy <= 1);
+// 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->x, e->y, p->x, p->y, e->vision_range);
 }
 
 // Check if position is occupied by player
@@ -178,7 +181,88 @@ static void enemy_move_toward_player(Enemy *e, Player *p, Map *map, Enemy *all_e
   }
 }
 
-// Perform a single action for an enemy (attack if adjacent, otherwise move)
+// Move enemy in a random direction (patrol)
+static void enemy_patrol(Enemy *e, Map *map, Enemy *all_enemies, int enemy_count) {
+  if (rng_int(0, 100) > ENEMY_PATROL_MOVE_CHANCE)
+    return;
+
+  int dx = rng_int(-1, 1);
+  int dy = rng_int(-1, 1);
+
+  if (dx == 0 && dy == 0)
+    return;
+
+  int new_x = e->x + dx;
+  int new_y = e->y + dy;
+
+  if (is_floor(map, new_x, new_y) && !is_enemy_at(all_enemies, enemy_count, new_x, new_y)) {
+    e->x = new_x;
+    e->y = new_y;
+  }
+}
+
+// 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->x)
+    dx = 1;
+  else if (e->last_known_x < e->x)
+    dx = -1;
+
+  if (e->last_known_y > e->y)
+    dy = 1;
+  else if (e->last_known_y < e->y)
+    dy = -1;
+
+  int new_x = e->x + dx;
+  int new_y = e->y;
+
+  if (dx != 0 && is_floor(map, new_x, new_y) && !is_enemy_at(all_enemies, enemy_count, new_x, new_y)) {
+    e->x = new_x;
+  } else if (dy != 0) {
+    new_x = e->x;
+    new_y = e->y + dy;
+    if (is_floor(map, new_x, new_y) && !is_enemy_at(all_enemies, enemy_count, new_x, new_y)) {
+      e->x = new_x;
+      e->y = new_y;
+    }
+  }
+
+  if (e->x == e->last_known_x && e->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].x - x;
+    int dy = enemies[i].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->x, e->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;
@@ -187,14 +271,37 @@ void enemy_act(Enemy *e, Player *p, Map *map, Enemy *all_enemies, int enemy_coun
   if (combat_has_effect(e->effects, e->effect_count, EFFECT_STUN))
     return;
 
-  // Check if adjacent to player - attack
-  if (can_see_player(e, p)) {
+  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->x;
+    e->last_known_y = p->y;
+  }
+
+  // Attack if adjacent to player
+  if (can_see && can_see_entity(map, e->x, e->y, p->x, p->y, 1)) {
     combat_enemy_attack(e, p);
+    propagate_alert(e, all_enemies, enemy_count);
     return;
   }
 
-  // Otherwise, move toward player
-  enemy_move_toward_player(e, p, map, all_enemies, enemy_count);
+  // 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;
+  }
+
+  // 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);
 }
 
 void enemy_update_all(Enemy enemies[], int count, Player *p, Map *map) {

src/main.c

@@ -122,6 +122,9 @@ static void init_floor(GameState *gs, int floor_num) {
   }
   gs->player.floor = floor_num;
 
+  // Calculate initial visibility
+  calculate_visibility(&gs->map, gs->player.x, gs->player.y);
+
   // Spawn enemies
   enemy_spawn(gs->enemies, &gs->enemy_count, &gs->map, &gs->player, floor_num);
 
@@ -215,6 +218,9 @@ static void post_action(GameState *gs, Enemy *attacked_enemy) {
     }
   }
 
+  // Update visibility based on player's new position
+  calculate_visibility(&gs->map, gs->player.x, gs->player.y);
+
   // Enemy turns - uses speed/cooldown system
   enemy_update_all(gs->enemies, gs->enemy_count, &gs->player, &gs->map);
 
@@ -246,6 +252,7 @@ static int handle_stun_turn(GameState *gs) {
   if (gs->game_over)
     return 1;
   enemy_update_all(gs->enemies, gs->enemy_count, &gs->player, &gs->map);
+  calculate_visibility(&gs->map, gs->player.x, gs->player.y);
   if (gs->player.hp <= 0)
     gs->game_over = 1;
   gs->last_message = "You are stunned!";
@@ -541,8 +548,8 @@ static void game_loop(void) {
     cam.offset = (Vector2){(float)gs.shake_x, (float)gs.shake_y};
     BeginMode2D(cam);
     render_map(&gs.map);
-    render_items(gs.items, gs.item_count);
-    render_enemies(gs.enemies, gs.enemy_count);
+    render_items(gs.items, gs.item_count, gs.map.visible);
+    render_enemies(gs.enemies, gs.enemy_count, gs.map.visible);
     render_player(&gs.player);
     EndMode2D();
 

src/map.c

@@ -1,6 +1,8 @@
 #include "map.h"
 #include "rng.h"
+#include "settings.h"
 #include "utils.h"
+#include <stdlib.h>
 #include <string.h>
 
 void map_init(Map *map) {
@@ -10,6 +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;
 }
 
@@ -186,3 +190,67 @@ void dungeon_generate(Dungeon *d, Map *map, int floor_num) {
   d->room_count = map->room_count;
   memcpy(d->rooms, map->rooms, sizeof(Room) * map->room_count);
 }
+
+int is_in_view_range(int x, int y, int view_x, int view_y, int range) {
+  int dx = x - view_x;
+  int dy = y - view_y;
+  return (dx * dx + dy * dy) <= (range * range);
+}
+
+static int trace_line_of_sight(const Map *map, int x1, int y1, int x2, int y2) {
+  int dx = abs(x2 - x1);
+  int dy = abs(y2 - y1);
+  int sx = (x1 < x2) ? 1 : -1;
+  int sy = (y1 < y2) ? 1 : -1;
+  int err = dx - dy;
+  int x = x1;
+  int y = y1;
+
+  while (1) {
+    if (!in_bounds(x, y, MAP_WIDTH, MAP_HEIGHT))
+      return 0;
+
+    if (x == x2 && y == y2)
+      return 1;
+
+    if (map->tiles[y][x] == TILE_WALL && !(x == x1 && y == y1))
+      return 0;
+
+    int e2 = 2 * err;
+    if (e2 > -dy) {
+      err -= dy;
+      x += sx;
+    }
+    if (e2 < dx) {
+      err += dx;
+      y += sy;
+    }
+  }
+}
+
+int has_line_of_sight(const Map *map, int x1, int y1, int x2, int y2) {
+  if (!in_bounds(x1, y1, MAP_WIDTH, MAP_HEIGHT) || !in_bounds(x2, y2, MAP_WIDTH, MAP_HEIGHT))
+    return 0;
+  return trace_line_of_sight(map, x1, y1, x2, y2);
+}
+
+int can_see_entity(const Map *map, int from_x, int from_y, int to_x, int to_y, int range) {
+  if (!is_in_view_range(to_x, to_y, from_x, from_y, range))
+    return 0;
+  return has_line_of_sight(map, from_x, from_y, to_x, to_y);
+}
+
+void calculate_visibility(Map *map, int x, int y) {
+  memset(map->visible, 0, sizeof(map->visible));
+
+  for (int ty = 0; ty < MAP_HEIGHT; ty++) {
+    for (int tx = 0; tx < MAP_WIDTH; tx++) {
+      if (is_in_view_range(tx, ty, x, y, PLAYER_VIEW_RANGE)) {
+        if (has_line_of_sight(map, x, y, tx, ty)) {
+          map->visible[ty][tx] = 1;
+          map->remembered[ty][tx] = 1;
+        }
+      }
+    }
+  }
+}

src/map.h

@@ -18,4 +18,10 @@ void map_init(Map *map);
 // Get a random floor tile position
 void get_random_floor_tile(Map *map, int *x, int *y, int attempts);
 
+// Visibility / Fog of War
+int is_in_view_range(int x, int y, int view_x, int view_y, int range);
+int has_line_of_sight(const Map *map, int x1, int y1, int x2, int y2);
+void calculate_visibility(Map *map, int x, int y);
+int can_see_entity(const Map *map, int from_x, int from_y, int to_x, int to_y, int range);
+
 #endif  // MAP_H

src/render.c

@@ -11,18 +11,31 @@ void render_map(const Map *map) {
   for (int y = 0; y < MAP_HEIGHT; y++) {
     for (int x = 0; x < MAP_WIDTH; x++) {
       Rectangle rect = {(float)(x * TILE_SIZE), (float)(y * TILE_SIZE), (float)TILE_SIZE, (float)TILE_SIZE};
+      int visible = map->visible[y][x];
+      int remembered = map->remembered[y][x];
+
+      if (!visible && !remembered) {
+        DrawRectangleRec(rect, (Color){5, 5, 10, 255});
+        continue;
+      }
+
+      Color wall_color = visible ? DARKGRAY : (Color){25, 25, 30, 255};
+      Color floor_color = visible ? BLACK : (Color){15, 15, 20, 255};
+      Color stairs_color = visible ? (Color){100, 100, 100, 255} : (Color){40, 40, 45, 255};
 
       switch (map->tiles[y][x]) {
       case TILE_WALL:
-        DrawRectangleRec(rect, DARKGRAY);
+        DrawRectangleRec(rect, wall_color);
         break;
       case TILE_FLOOR:
-        DrawRectangleRec(rect, BLACK);
+        DrawRectangleRec(rect, floor_color);
         break;
       case TILE_STAIRS:
-        DrawRectangleRec(rect, (Color){100, 100, 100, 255});
-        // Draw stairs marker
-        DrawText(">", x * TILE_SIZE + 4, y * TILE_SIZE + 2, 12, WHITE);
+        DrawRectangleRec(rect, stairs_color);
+        if (visible)
+          DrawText(">", x * TILE_SIZE + 4, y * TILE_SIZE + 2, 12, WHITE);
+        else
+          DrawText(">", x * TILE_SIZE + 4, y * TILE_SIZE + 2, 12, (Color){60, 60, 65, 255});
         break;
       }
     }
@@ -34,10 +47,12 @@ void render_player(const Player *p) {
   DrawRectangleRec(rect, BLUE);
 }
 
-void render_enemies(const Enemy *enemies, int count) {
+void render_enemies(const Enemy *enemies, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH]) {
   for (int i = 0; i < count; i++) {
     if (!enemies[i].alive)
       continue;
+    if (!visible[enemies[i].y][enemies[i].x])
+      continue;
 
     Rectangle rect = {(float)(enemies[i].x * TILE_SIZE), (float)(enemies[i].y * TILE_SIZE), (float)TILE_SIZE,
                       (float)TILE_SIZE};
@@ -79,10 +94,12 @@ void render_enemies(const Enemy *enemies, int count) {
   }
 }
 
-void render_items(const Item *items, int count) {
+void render_items(const Item *items, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH]) {
   for (int i = 0; i < count; i++) {
     if (items[i].picked_up)
       continue;
+    if (!visible[items[i].y][items[i].x])
+      continue;
 
     Rectangle rect = {(float)(items[i].x * TILE_SIZE), (float)(items[i].y * TILE_SIZE), (float)TILE_SIZE,
                       (float)TILE_SIZE};

src/render.h

@@ -80,10 +80,10 @@ void render_map(const Map *map);
 void render_player(const Player *p);
 
 // Render all enemies
-void render_enemies(const Enemy *enemies, int count);
+void render_enemies(const Enemy *enemies, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH]);
 
 // Render all items
-void render_items(const Item *items, int count);
+void render_items(const Item *items, int count, const unsigned char visible[MAP_HEIGHT][MAP_WIDTH]);
 
 // Render UI overlay
 void render_ui(const Player *p);

src/settings.h

@@ -63,4 +63,9 @@
 // Message timer
 #define MESSAGE_TIMER_DURATION 60
 
+// Visibility / Fog of War
+#define PLAYER_VIEW_RANGE 8
+#define ENEMY_VIEW_RANGE 6
+#define ENEMY_PATROL_MOVE_CHANCE 30
+
 #endif  // SETTINGS_H