bats now back off after an attack

src/enemies.c

@@ -6,6 +6,7 @@
 #include "aoe.h"
 #include "enemies.h"
 #include "skills.h"
+#include <gint/defs/util.h>
 #include <string.h>
 
 /* Declare animations for an enemy */
@@ -35,6 +36,11 @@ static enemy_t const slime_1 = {
     .shadow_size = 4,
     .xp = 2,
     .z = 0,
+    .ai_data_size = 0,
+};
+
+struct bat_ai {
+    fixed_t retreat_period;
 };
 
 static enemy_t const bat_2 = {
@@ -56,6 +62,7 @@ static enemy_t const bat_2 = {
     .shadow_size = 4,
     .xp = 6,
     .z = fix(0.75),
+    .ai_data_size = sizeof(struct bat_ai),
 };
 
 static enemy_t const fire_slime_4 = {
@@ -77,6 +84,7 @@ static enemy_t const fire_slime_4 = {
     .shadow_size = 4,
     .xp = 14,
     .z = 0,
+    .ai_data_size = 0,
 };
 
 static enemy_t const gunslinger_8 = {
@@ -98,6 +106,7 @@ static enemy_t const gunslinger_8 = {
     .shadow_size = 4,
     .xp = 30,
     .z = fix(0.25),
+    .ai_data_size = 0,
 };
 
 static enemy_t const * const enemies[] = {
@@ -151,13 +160,18 @@ entity_t *enemy_make(int enemy_id)
     fighter_set_stats(f, &data->stats, data->level, fix(1.0));
     f->HP = f->HP_max;
     f->combo_length = 1;
-    f->enemy = malloc(sizeof *f->enemy);
+    f->enemy = malloc(sizeof *f->enemy + data->ai_data_size);
     f->enemy->id = data;
     f->enemy->pathfind_dir = (vec2){ 0, 0 };
     f->enemy->pathfind_cycles = 0;
+    f->enemy->ai_data = (void *)f->enemy + sizeof *f->enemy;
 
-    /* Specify skills */
-    if(enemy_id == ENEMY_GUNSLINGER_8) {
+    /* Specify skills and initialize AI data */
+    if(enemy_id == ENEMY_BAT_2) {
+        struct bat_ai *ai_data = f->enemy->ai_data;
+        ai_data->retreat_period = 0;
+    }
+    else if(enemy_id == ENEMY_GUNSLINGER_8) {
         f->skills[0] = AOE_PROJECTILE;
     }
 
@@ -216,6 +230,28 @@ static bool move_within_range_of_player(game_t *g, entity_t *e, fixed_t range,
     return false;
 }
 
+static bool move_away_from_player_range(game_t *g, entity_t *e, fixed_t range,
+    fixed_t dt)
+{
+    physical_t *p = getcomp(e, physical);
+    fighter_t *f = getcomp(e, fighter);
+    if(!p || !f || !f->enemy)
+        return true;
+
+    if(dist2(physical_pos(e), physical_pos(g->player)) > fmul(range, range))
+        return true;
+
+    /* Escape opposite the direction of normal movement */
+    vec2 direction = f->enemy->pathfind_dir;
+    direction = (vec2){ -direction.x, -direction.y };
+
+    mechanical_move(e, direction, dt, g->map);
+    if(p->x < getcomp(g->player, physical)->x) p->facing = RIGHT;
+    else p->facing = LEFT;
+
+    return false;
+}
+
 static bool contact_attack(game_t *g, entity_t *e)
 {
     fighter_t *f = getcomp(e, fighter);
@@ -254,12 +290,27 @@ void enemy_ai(game_t *g, entity_t *e, fixed_t dt)
 {
     fighter_t *f = getcomp(e, fighter);
 
-    if(f->enemy->id == &slime_1 || f->enemy->id == &bat_2) {
+    if(f->enemy->id == &slime_1) {
         if(move_within_range_of_player(g, e, fix(1.0), dt)) {
             contact_attack(g, e);
         }
     }
 
+    else if(f->enemy->id == &bat_2) {
+        struct bat_ai *ai_data = f->enemy->ai_data;
+
+        /* After an attack, move away for a couple of seconds */
+        if(ai_data->retreat_period > 0) {
+            move_away_from_player_range(g, e, fix(3.0), dt);
+            ai_data->retreat_period = max(ai_data->retreat_period-dt, fix(0));
+        }
+        /* Otherwise, get close and attack */
+        else if(move_within_range_of_player(g, e, fix(1.0), dt)) {
+            contact_attack(g, e);
+            ai_data->retreat_period = fix(1.5);
+        }
+    }
+
     else if(f->enemy->id == &fire_slime_4) {
     }
 

src/enemies.h

@@ -32,6 +32,8 @@ typedef struct
     uint16_t xp;
     /* Rendering elevation */
     fixed_t z;
+    /* Size of the monster-specific data structure for IA */
+    size_t ai_data_size;
 
 } enemy_t;
 
@@ -51,6 +53,8 @@ typedef struct enemy_data {
     vec2 pathfind_dir;
     /* Number of frames left until next pathfinding cycle */
     uint8_t pathfind_cycles;
+    /* Pointer to AI-specific data */
+    void *ai_data;
 
 } enemy_data_t;