Multiplayer continues after a player leaves: AI side takeover, background match while menus are open, match chat, five-tile fog start

src/game.rs

@@ -607,6 +607,10 @@ pub struct Game {
     #[serde(skip)]
     pub netplay: Option<crate::netplay::Netplay>, // a match: turns come in, the world steps per turn
     #[serde(skip)]
+    pub ai_sides: Vec<u8>, // match sides whose human master left: AI keeps them playing
+    #[serde(skip)]
+    pub ai_difficulty: u8, // difficulty used when a left side becomes an AI rival
+    #[serde(skip)]
     pub hints: bool, // show hint messages (setting)
     #[serde(skip, default = "hint_times")]
     hint_t: [f32; 32], // last time each hint slot was shown
@@ -788,6 +792,8 @@ impl Game {
             sim_steps: 0,
             step_acc: 0.0,
             netplay: None,
+            ai_sides: Vec::new(),
+            ai_difficulty: 1,
             hint_t: hint_times(),
             reserve: 0.0,
             incoming: Vec::new(),
@@ -1265,6 +1271,10 @@ impl Game {
         side == self.me_side || self.masters.iter().any(|m| m.side == side)
     }
 
+    pub fn is_rival_side(&self, side: u8) -> bool {
+        self.rivals.iter().any(|r| r.alive && r.side == side)
+    }
+
     fn take_active(&mut self) -> MasterState {
         MasterState {
             side: self.me_side,
@@ -2120,7 +2130,7 @@ impl Game {
             self.demo_ai(e, dt);
         } else if e.hero && e.captive != 0 {
             self.captive_update(e, dt);
-        } else if e.rival() {
+        } else if self.is_rival_side(e.side) || (e.rival() && !self.is_master(e.side)) {
             self.rival_ai(e, dt);
         } else if e.dwarf() {
             self.dwarf_ai(e, dt);
@@ -2181,7 +2191,7 @@ impl Game {
             }
         }
         if !tile.walkable() && !(flies(e.kind) && tile.liquid()) {
-            if (e.hero || e.rival()) && tile.diggable() {
+            if (e.hero || self.is_rival_side(e.side) || (e.rival() && !self.is_master(e.side))) && tile.diggable() {
                 // heroes dig their way through
                 e.working = true;
                 let (tx, ty) = xy(next);