Automated balance runs; AI masters keep growing, mine more, defend with the rally flag and spells; Builder talent stronger

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/ai.rs

@@ -14,8 +14,9 @@ const THINK: [f32; 3] = [5.2, 3.25, 1.95]; // seconds between two thoughts (a ca
 const MAX_RADIUS: [i32; 3] = [11, 15, 19]; // how far the dungeon grows around the heart
 const MAX_IMPS: [usize; 3] = [5, 7, 9];
 const FIRST_ATTACK: [f32; 3] = [940.0, 625.0, 430.0]; // no attack before (seconds)
-const BOLDNESS: [f32; 3] = [1.5, 1.15, 0.9]; // own army / enemy army needed to attack
+const BOLDNESS: [f32; 3] = [1.0, 1.2, 1.35]; // own army / enemy army needed to attack (easy is reckless, hard waits)
 const MARK_REACH: i32 = 5; // an AI master marks only this close to its own ground
+const CREATURE_TARGET: [usize; 3] = [30, 50, 80]; // beds an AI master builds up to
 const MAX_TOWERS: [usize; 3] = [1, 2, 4];
 const START_GOLD: [f32; 3] = [1500.0, 2500.0, 3500.0];
 
@@ -51,10 +52,11 @@ impl Game {
         self.ai_imps(d, cx, cy);
         self.ai_dig(k, d, cx, cy);
         self.ai_gold(cx, cy);
-        self.ai_rooms(cx, cy);
+        self.ai_rooms(d, cx, cy);
         self.ai_towers(d, cx, cy);
         self.ai_fight(k, d, side, cx, cy);
-        self.ai_talents();
+        let focus = self.rivals[k].focus;
+        self.ai_talents(focus);
     }
 
     // the tiles an AI master may mark: within MARK_REACH tiles of its own ground
@@ -161,18 +163,23 @@ impl Game {
 
     // gold running low: a tunnel to the nearest vein that nobody works on yet
     fn ai_gold(&mut self, cx: i32, cy: i32) {
-        if self.gold > 1500.0 {
+        // gold for one and a half paydays and a little more: enough
+        if self.gold > self.next_payday_cost() * 1.5 + 1000.0 {
             return;
         }
         let me = self.me;
-        // a marked vein the imps can reach (next to own ground) is being worked already
-        let busy = (0..self.map.t.len()).any(|i| {
-            let t = &self.map.t[i];
-            let (x, y) = xy(i);
-            t.marked && t.vein().is_some() && DIR4.iter().any(|&(dx, dy)| self.map.get(x + dx, y + dy).map_or(false, |n| n.owner == me && n.walkable()))
-        });
-        if busy {
-            return; // a vein is being worked already
+        // marked veins the imps can reach (next to own ground) are being worked already; one vein
+        // for every three imps at a time
+        let side = me.side().min(7);
+        let busy = (0..self.map.t.len())
+            .filter(|&i| {
+                let t = &self.map.t[i];
+                let (x, y) = xy(i);
+                t.marked && t.mark_by == side && t.vein().is_some() && DIR4.iter().any(|&(dx, dy)| self.map.get(x + dx, y + dy).map_or(false, |n| n.owner == me && n.walkable()))
+            })
+            .count();
+        if busy >= (self.worker_count() / 3).max(1) {
+            return;
         }
         self.ai_mark_tunnel(cx, cy, |g: &Game, i: usize| {
             let t = &g.map.t[i];
@@ -220,7 +227,7 @@ impl Game {
     }
 
     // the next room of the build order, where there is free own floor for it
-    fn ai_rooms(&mut self, cx: i32, cy: i32) {
+    fn ai_rooms(&mut self, d: usize, cx: i32, cy: i32) {
         for &(room, w, h, n) in BUILD.iter() {
             // only what this master has researched (the same rules as the player)
             if !self.ai_knows(crate::ui::Tool::Room(room)) {
@@ -239,6 +246,29 @@ impl Game {
             }
             return;
         }
+        // the base is done: a bigger treasury when it is nearly full
+        if self.gold > self.gold_cap() * 0.85 {
+            let cost = ROOM_COST[0] as f32 * 9.0;
+            if self.gold >= cost + 400.0 {
+                if let Some((x0, y0)) = self.ai_free_rect(cx, cy, 3, 3) {
+                    self.build_rect(0, x0, y0, x0 + 2, y0 + 2);
+                    return;
+                }
+            }
+        }
+        // more beds and food while the army may still grow (by difficulty)
+        if self.counts[1] >= CREATURE_TARGET[d] || self.free_beds() > 2 {
+            return;
+        }
+        let room = if self.counts[2] * 10 < self.counts[1] * 6 { 2 } else { 1 };
+        let (w, h) = (4, 3);
+        let cost = ROOM_COST[room] as f32 * (w * h) as f32;
+        if self.gold < cost + 400.0 {
+            return;
+        }
+        if let Some((x0, y0)) = self.ai_free_rect(cx, cy, w, h) {
+            self.build_rect(room, x0, y0, x0 + w - 1, y0 + h - 1);
+        }
     }
 
     // has this master researched the tool (rooms, towers)?
@@ -295,6 +325,11 @@ impl Game {
             self.place_mark(cx + 1, cy + 3, false);
         }
         let army = self.side_army(side);
+        // heroes or enemy units in the dungeon: everybody goes for them (the rally flag) and the
+        // master casts lightning on them and heals his hurt creatures
+        if !self.is_partner(side) && self.ai_defend(k) {
+            return;
+        }
         // co-op: go where the allies go
         if self.is_partner(side) {
             let lead = self.master_sides().into_iter().find(|&s| s != side && !self.is_out(s) && self.allied(side, s));
@@ -363,6 +398,49 @@ impl Game {
         }
     }
 
+    // the defence of the dungeon; true while there are intruders
+    fn ai_defend(&mut self, k: usize) -> bool {
+        let me = self.me;
+        let intruders: Vec<(f32, f32)> = self
+            .ents
+            .iter()
+            .filter(|e| e.alive && !e.held && e.captive == 0 && self.is_hostile(e) && self.map.get(e.x as i32, e.y as i32).map_or(false, |t| t.owner == me))
+            .map(|e| (e.x, e.y))
+            .collect();
+        if intruders.is_empty() {
+            if self.rivals[k].defending {
+                self.rivals[k].defending = false;
+                self.flag = None;
+            }
+            return false;
+        }
+        // the middle of the intruders, on walkable ground
+        let n = intruders.len() as f32;
+        let (mx, my) = intruders.iter().fold((0.0, 0.0), |a, p| (a.0 + p.0 / n, a.1 + p.1 / n));
+        let near = intruders.iter().min_by(|a, b| ((a.0 - mx).powi(2) + (a.1 - my).powi(2)).partial_cmp(&((b.0 - mx).powi(2) + (b.1 - my).powi(2))).unwrap()).copied().unwrap();
+        let tile = idx(near.0 as i32, near.1 as i32);
+        if self.rivals[k].attacking {
+            self.rivals[k].attacking = false; // home first
+        }
+        self.rivals[k].defending = true;
+        if self.map.t[tile].walkable() && self.flag != Some(tile) {
+            self.flag = Some(tile);
+        }
+        // lightning on the thickest of them, healing for the hurt
+        let bolt = 50.0 * self.talents.spell_cost();
+        if self.mana >= bolt + 40.0 && self.known(crate::game::LIGHTNING_TOOL) {
+            self.lightning(near.0, near.1);
+        }
+        let heal = 60.0 * self.talents.spell_cost();
+        let hurt = self.ents.iter().filter(|e| e.alive && e.creature() && e.hp < e.max_hp * 0.5 && (e.x - near.0).powi(2) + (e.y - near.1).powi(2) < 36.0).map(|e| (e.x, e.y)).next();
+        if let Some((hx, hy)) = hurt {
+            if self.mana >= heal + 40.0 && self.known(crate::game::HEAL_TOOL) {
+                self.heal(hx, hy);
+            }
+        }
+        true
+    }
+
     // is an enemy heart near tile f?
     fn ai_enemy_heart_near(&self, side: u8, f: usize) -> bool {
         let (fx, fy) = xy(f);

src/balance.rs

@@ -0,0 +1,206 @@
+// Automated balancing: whole games played by the AI brain on every side, headless and
+// deterministic, many seeds each. Run with
+//   cargo test --release balance_ -- --ignored --nocapture --test-threads=4
+// and read the tables (docs/BALANCE.md keeps the findings).
+
+#![cfg(test)]
+
+use crate::game::*;
+use crate::rival::{Rival, PARTNER_GIFT_EVERY, RIVAL_CORE_HP};
+
+const STEP: f32 = 0.05;
+
+// the master on side 0 gets the same brain as the rivals
+fn pilot(g: &mut Game, difficulty: u8, focus: Option<u8>) {
+    let core = g.map.core;
+    // like every AI master: the 9x9 starting area and a portal of its own beside it
+    g.carve_master_area(0, core);
+    g.add_master_portal(0, core);
+    g.rivals.push(Rival { side: 0, core, hp: RIVAL_CORE_HP, alive: true, radius: 5, grow_t: 0.0, spawn_t: 0.0, attack_t: 0.0, difficulty, power: 0.0, gift_t: PARTNER_GIFT_EVERY, think_t: 1.0, attacking: false, army0: 0.0, focus, defending: false });
+}
+
+// the other corners of a square map for up to three more masters (centre of the core)
+fn corners(w: i32, h: i32) -> [(i32, i32); 3] {
+    [(w - 29, 13), (w - 29, h - 15), (15, h - 15)]
+}
+
+#[derive(Clone, Debug, Default)]
+struct Outcome {
+    out_at: Vec<(u8, f32)>, // side, minute it fell
+    score: Vec<(u8, f32)>,  // side, strength at the end (alive ones)
+    winner: Option<u8>,
+    minutes: f32,
+}
+
+fn alive(g: &Game, side: u8) -> bool {
+    g.core_hp_of(side) > 0.0 && g.rivals.iter().any(|r| r.side == side && r.alive)
+}
+
+fn score(g: &Game, side: u8) -> f32 {
+    g.core_hp_of(side) * 2.0 + g.side_army(side) + g.gold_of(side) * 0.2
+}
+
+// plays until one side is left or the time is up; side 0 falling does not stop it
+fn play(g: &mut Game, sides: &[u8], max_min: f32) -> Outcome {
+    let mut o = Outcome::default();
+    let steps = (max_min * 60.0 / STEP) as usize;
+    for k in 0..steps {
+        g.update(STEP);
+        if g.state != 0 {
+            g.state = 0; // the harness decides the end
+        }
+        if k % 20 == 0 {
+            for &s in sides {
+                if !o.out_at.iter().any(|x| x.0 == s) && !alive(g, s) {
+                    o.out_at.push((s, g.time / 60.0));
+                }
+            }
+            let left: Vec<u8> = sides.iter().copied().filter(|&s| !o.out_at.iter().any(|x| x.0 == s)).collect();
+            if left.len() <= 1 {
+                o.winner = left.first().copied();
+                break;
+            }
+        }
+    }
+    o.minutes = g.time / 60.0;
+    o.score = sides.iter().copied().filter(|&s| !o.out_at.iter().any(|x| x.0 == s)).map(|s| (s, score(g, s))).collect();
+    if o.winner.is_none() {
+        o.winner = o.score.iter().max_by(|a, b| a.1.partial_cmp(&b.1).unwrap()).map(|x| x.0);
+    }
+    o
+}
+
+fn arena(seed: u32, size: usize) -> Game {
+    let mut g = Game::new(seed, size, size);
+    g.gate_on = false; // no hero waves: masters against each other
+    g.ai_difficulty = 1;
+    g
+}
+
+fn seeds() -> Vec<u32> {
+    let n: u32 = std::env::var("BALANCE_SEEDS").ok().and_then(|s| s.parse().ok()).unwrap_or(6);
+    (1..=n).map(|k| 1000 + k * 37).collect()
+}
+
+// ---------------------------------------------------------------- difficulty duels
+
+#[test]
+#[ignore]
+fn balance_difficulty() {
+    println!("\n== difficulty duels (2 masters, 112x112, no waves, 45 min) ==");
+    println!("{:<14} {:>5} {:>5} {:>5} {:>8}", "pair", "A", "B", "draw", "min");
+    for (a, b) in [(0u8, 1u8), (1, 2), (0, 2), (1, 1)] {
+        let (mut wa, mut wb, mut dr, mut mins) = (0, 0, 0, 0.0);
+        for (k, seed) in seeds().into_iter().enumerate() {
+            let mut g = arena(seed, 112);
+            // swap who plays which side every other seed (side 0 has the map's own start)
+            let (d0, d2) = if k % 2 == 0 { (a, b) } else { (b, a) };
+            pilot(&mut g, d0, None);
+            let (x, y) = corners(112, 112)[k % 3];
+            g.add_rival(2, x, y, d2);
+            let o = play(&mut g, &[0, 2], 45.0);
+            mins += o.minutes;
+            let a_side = if k % 2 == 0 { 0 } else { 2 };
+            let decisive = o.out_at.len() == 1;
+            match o.winner {
+                Some(w) if decisive && w == a_side => wa += 1,
+                Some(_) if decisive => wb += 1,
+                _ => dr += 1,
+            }
+        }
+        let n = seeds().len() as f32;
+        println!("{:<14} {:>5} {:>5} {:>5} {:>8.1}", format!("{} vs {}", a, b), wa, wb, dr, mins / n);
+    }
+}
+
+// ---------------------------------------------------------------- talent branches
+
+#[test]
+#[ignore]
+fn balance_talents() {
+    use crate::talents::*;
+    println!("\n== talent tournament (4 masters, medium, 128x128, no waves, 50 min) ==");
+    let names = ["builder", "warlord", "warlock", "merchant"];
+    let mut wins = [0usize; 4];
+    let mut place_sum = [0.0f32; 4];
+    let mut lv_sum = [0.0f32; 4];
+    let sides = [0u8, 2, 3, 4];
+    for (k, seed) in seeds().into_iter().enumerate() {
+        let mut g = arena(seed, 128);
+        // the branches move round the four starts from seed to seed
+        let branch_of = |s: usize| ((s + k) % 4) as u8;
+        pilot(&mut g, 1, Some(branch_of(0)));
+        for (n, &(x, y)) in corners(128, 128).iter().enumerate() {
+            g.add_rival(sides[n + 1], x, y, 1);
+            g.rivals.last_mut().unwrap().focus = Some(branch_of(n + 1));
+        }
+        let o = play(&mut g, &sides, 50.0);
+        // placement: the winner 1st, the survivors by score, the fallen by how long they lasted
+        let mut order: Vec<u8> = Vec::new();
+        let mut alive_sorted = o.score.clone();
+        alive_sorted.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap());
+        order.extend(alive_sorted.iter().map(|x| x.0));
+        let mut fallen = o.out_at.clone();
+        fallen.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap());
+        order.extend(fallen.iter().map(|x| x.0));
+        for (place, &s) in order.iter().enumerate() {
+            let n = sides.iter().position(|&x| x == s).unwrap();
+            let b = branch_of(n) as usize;
+            place_sum[b] += place as f32 + 1.0;
+            if place == 0 {
+                wins[b] += 1;
+            }
+            lv_sum[b] += g.talents_of(s).lv[b] as f32;
+        }
+        let _ = BRANCHES;
+    }
+    let n = seeds().len() as f32;
+    println!("{:<10} {:>5} {:>10} {:>10}", "branch", "wins", "avg place", "avg level");
+    for b in 0..4 {
+        println!("{:<10} {:>5} {:>10.2} {:>10.1}", names[b], wins[b], place_sum[b] / n, lv_sum[b] / n);
+    }
+}
+
+// ---------------------------------------------------------------- one master against the waves
+
+#[test]
+#[ignore]
+fn balance_waves() {
+    println!("\n== one AI master against the hero waves (96x96, 40 min) ==");
+    println!("{:<6} {:>8} {:>6} {:>7} {:>7} {:>7} {:>6}", "diff", "fell@min", "wave", "heroes", "lost", "gold", "army");
+    for d in 0..3u8 {
+        for seed in seeds() {
+            let mut g = Game::new(seed, 96, 96);
+            g.ai_difficulty = d;
+            pilot(&mut g, d, None);
+            let mut fell = None;
+            for k in 0..((40.0 * 60.0 / STEP) as usize) {
+                g.update(STEP);
+                if g.state != 0 {
+                    if g.core_hp <= 0.0 {
+                        fell = Some(g.time / 60.0);
+                        break;
+                    }
+                    g.state = 0;
+                }
+                if std::env::var("BALANCE_TRACE").is_ok() && k % (120.0 / STEP) as usize == 0 {
+                    let rooms: usize = g.counts.iter().sum();
+                    let portal = (0..g.map.portals.len()).any(|p| g.map.portal_owner(p) == crate::map::Owner::Player);
+                    println!("   seed {} d{} min {:>4.1}: creatures {:>3} imps {:>2} gold {:>6} rooms {:>3} lair {:>3} farm {:>3} wave {:>2} core {:>5} portal {} heroes near {}",
+                        seed, d, g.time / 60.0, g.creature_count(), g.worker_count(), g.gold as i32, rooms, g.counts[1], g.counts[2], g.wave, g.core_hp as i32, portal,
+                        g.ents.iter().filter(|e| e.alive && e.active_hero()).count());
+                }
+            }
+            println!(
+                "{:<6} {:>8} {:>6} {:>7} {:>7} {:>7} {:>6}",
+                d,
+                fell.map_or("-".to_string(), |m| format!("{:.1}", m)),
+                g.wave,
+                g.stats.get(crate::stats::HEROES) as i32,
+                g.stats.get(crate::stats::LOST) as i32,
+                g.gold as i32,
+                g.side_army(0) as i32
+            );
+        }
+    }
+}

src/game.rs

@@ -161,6 +161,8 @@ pub struct St {
 
 pub const RUNE_TOOL: usize = 20; // index of the rune forge tower in ui::TOOLS
 pub const SUMMON_TOOL: usize = 11; // index of summoning in ui::TOOLS
+pub const LIGHTNING_TOOL: usize = 9; // lightning in ui::TOOLS
+pub const HEAL_TOOL: usize = 10; // healing in ui::TOOLS
 
 pub fn st(k: EK) -> St {
     let s = |name, hp, atk, range, speed, interval, wage, bounty| St { name, hp, atk, range, speed, interval, wage, bounty };

src/main.rs

@@ -30,6 +30,7 @@ mod props;
 mod research;
 mod rival;
 mod rogues;
+mod balance;
 mod talents;
 mod weather;
 mod names;

src/netplay.rs

@@ -365,7 +365,7 @@ impl Game {
             // the seat keeps its master (dungeon, gold, creatures): the brain (ai.rs) plays it
             let core = self.core_of_side(side);
             let difficulty = self.ai_difficulty;
-            self.rivals.push(crate::rival::Rival { side, core, hp: crate::rival::RIVAL_CORE_HP, alive: true, radius: 6, grow_t: 0.0, spawn_t: 0.0, attack_t: 0.0, difficulty, power: 0.0, gift_t: crate::rival::PARTNER_GIFT_EVERY, think_t: 1.0, attacking: false, army0: 0.0 });
+            self.rivals.push(crate::rival::Rival { side, core, hp: crate::rival::RIVAL_CORE_HP, alive: true, radius: 6, grow_t: 0.0, spawn_t: 0.0, attack_t: 0.0, difficulty, power: 0.0, gift_t: crate::rival::PARTNER_GIFT_EVERY, think_t: 1.0, attacking: false, army0: 0.0, focus: None, defending: false });
         }
     }
 

src/rival.rs

@@ -33,6 +33,10 @@ pub struct Rival {
     pub attacking: bool, // the attack flag is set on an enemy heart
     #[serde(default)]
     pub army0: f32, // army strength when the attack began
+    #[serde(default)]
+    pub focus: Option<u8>, // balance runs: this master learns only one talent branch
+    #[serde(default)]
+    pub defending: bool, // the rally flag is on intruders in the dungeon (ai.rs)
 }
 
 impl Rival {
@@ -98,7 +102,7 @@ impl Game {
         let core = (cx - 1, cy - 1);
         self.carve_master_area(side, core);
         self.add_master_portal(side, core);
-        self.rivals.push(Rival { side, core, hp: RIVAL_CORE_HP, alive: true, radius: 5, grow_t: 20.0, spawn_t: 5.0, attack_t: 0.0, difficulty, power: 0.0, gift_t: PARTNER_GIFT_EVERY, think_t: 2.0, attacking: false, army0: 0.0 });
+        self.rivals.push(Rival { side, core, hp: RIVAL_CORE_HP, alive: true, radius: 5, grow_t: 20.0, spawn_t: 5.0, attack_t: 0.0, difficulty, power: 0.0, gift_t: PARTNER_GIFT_EVERY, think_t: 2.0, attacking: false, army0: 0.0, focus: None, defending: false });
         self.adopt_master(side, core, difficulty, true);
     }
 

src/talents.rs

@@ -73,10 +73,10 @@ impl Talents {
     }
     // Builder: imps dig and claim faster, rooms cost less
     pub fn dig_speed(&self) -> f32 {
-        1.0 + 0.1 * self.level(BUILDER)
+        1.0 + 0.15 * self.level(BUILDER)
     }
     pub fn room_cost(&self) -> f32 {
-        1.0 - 0.06 * self.level(BUILDER)
+        1.0 - 0.1 * self.level(BUILDER)
     }
     // Warlord: creatures hit harder and take less damage
     pub fn damage(&self) -> f32 {
@@ -136,8 +136,16 @@ impl Game {
         self.sfx_ui(Sfx::LevelUp);
     }
 
-    // an AI master spends his points by himself: the branches in turn, the lowest first
-    pub(crate) fn ai_talents(&mut self) {
+    // an AI master spends his points by himself: the branches in turn, the lowest first (a balance
+    // run may hold him to one branch)
+    pub(crate) fn ai_talents(&mut self, focus: Option<u8>) {
+        if let Some(b) = focus {
+            let b = b as usize;
+            while self.talents.free() > 0 && self.talents.lv[b] < MAX_LEVEL {
+                self.talents.lv[b] += 1;
+            }
+            return;
+        }
         while self.talents.free() > 0 {
             let order = [WARLORD, BUILDER, MERCHANT, WARLOCK];
             let Some(&b) = order.iter().filter(|&&b| self.talents.lv[b] < MAX_LEVEL).min_by_key(|&&b| self.talents.lv[b]) else { break };
@@ -213,7 +221,7 @@ mod tests {
     fn ai_masters_spend_their_points() {
         let mut g = Game::new(9, 64, 64);
         g.talents.xp = point_xp(6);
-        g.ai_talents();
+        g.ai_talents(None);
         assert_eq!(g.talents.free(), 0);
         assert!(g.talents.lv.iter().all(|&l| l >= 1), "{:?}", g.talents.lv);
     }

src/ui.rs

@@ -559,7 +559,7 @@ fn branch_text(t: &crate::talents::Talents, b: usize) -> String {
     let desc = |lv: u8| {
         let l = lv as i32;
         let (a, c) = match b {
-            BUILDER => (10 * l, 6 * l),
+            BUILDER => (15 * l, 10 * l),
             WARLORD => (5 * l, 5 * l),
             WARLOCK => (15 * l, 6 * l),
             _ => (6 * l, 6 * l),