Simulation runs in fixed steps of 1/50 s (50 steps a second) instead of 1/20 s, with at most twelve catch-up steps in one frame

VERSION

@@ -1 +1 @@
-v202611-00002
+v202611-00003

docs/MULTIPLAYER.md

@@ -22,7 +22,7 @@ The server does not simulate; it relays:
 
 1. Clients send their **commands** (dig, build, cast, hand, orders, ...) to the server.
 2. Every 100 ms the server sends **turn N**: the commands of all players for that turn.
-3. Each client applies turn N and simulates two fixed steps of 50 ms. Turns arrive in order; a client waits
+3. Each client applies turn N and simulates five fixed steps of 20 ms. Turns arrive in order; a client waits
    for the next turn, so a missing player stalls everybody - exactly the "pause while missing" rule.
 4. Clients send a **checksum** of the game state every few seconds; a mismatch (desync) is reported.
 
@@ -38,10 +38,10 @@ per turn. Fog of war, particles and the camera are local and not part of the sha
   `Cast`, `Flag`, `Pickup`, `Drop`, `Slap`, `Attack`, `Guard`, `CancelOrders`, ...) wrapped in a
   `Command { side, seq, act }`. Creature targets are *ids*, so they mean the same on every client.
   The tools in `main.rs` only queue commands now - nothing touches the world directly.
-- **Steps**: the simulation runs in fixed steps of `STEP` = 50 ms (`Game::update` feeds real time into
+- **Steps**: the simulation runs in fixed steps of `STEP` = 20 ms, 50 steps a second (`Game::update` feeds real
-  them, `Game::apply_turn(cmds, steps)` is the lockstep entry point). Commands are applied at step
+  time into them, `Game::apply_turn(cmds, steps)` is the lockstep entry point; one server turn of 100 ms is five
-  boundaries, so single player and a match run exactly the same path. Particles, effects and the camera
+  steps). Commands are applied at step boundaries, so single player and a match run exactly the same path.
-  keep running in real time: they are local and not part of the shared state.
+  Particles, effects and the camera keep running in real time: they are local and not part of the shared state.
 - **Who speaks**: messages, hints and interface sounds belong to the master who is being processed
   (`Game::speaking`); what another master orders never shows up on my screen.
 - Savegames, tests and the standalone file are unchanged: `cargo test --release` covers the command path

src/commands.rs

@@ -239,7 +239,7 @@ mod tests {
         a.queue(Act::Pickup { ent: ogre });
         a.queue(Act::Drop { x: drop_at.0, y: drop_at.1 });
         for _ in 0..20 {
-            a.update(0.05);
+            a.update(STEP);
         }
 
         // the same game driven like a match (one turn with all commands, then the same steps)

src/game.rs

@@ -605,9 +605,9 @@ fn hint_times() -> [f32; 32] {
 
 // every simulation step has the same length: on every client of a match the same commands are
 // applied and then the same number of steps runs, so the worlds stay identical
-pub const STEP: f32 = 0.05;
+pub const STEP: f32 = 1.0 / 50.0; // 50 steps a second
 // one frame never runs away into the future (a lagging tab catches up at most this much)
-const MAX_STEPS_PER_FRAME: usize = 4;
+const MAX_STEPS_PER_FRAME: usize = 12;
 
 // torch on a wall face: wall tile + direction (index into DIR4) towards the open side
 #[derive(Clone, Copy, PartialEq, Serialize, Deserialize)]