Add spawn points

src/match_loading.rs

@@ -21,7 +21,6 @@ use crate::{
     },
     input::{LocalInputAssignments, LocalInputSource},
     match_runtime::MatchState,
-    math::{int::FGi32, vec::FGVec2},
     netcode::{
         GGRSCfg,
         session::{ConnectionStatus, SessionConfig, create_session},
@@ -277,7 +276,7 @@ pub fn prepare_match(
     if !valid_player_handles(&config.players) {
         fail_match(
             &mut next_state,
-            "player handles must be unique and cover 0..player_count",
+            "player handles must be unique and non-empty",
         );
         return;
     }
@@ -287,6 +286,20 @@ pub fn prepare_match(
         return;
     }
 
+    let stage_handle = stage_registry
+        .get(config.stage)
+        .expect("Initialization check should ensure all stages exist");
+    let stage_manifest = stage_manifests
+        .get(&stage_handle)
+        .expect("Initialization check should ensure stage manifests are kept alive");
+    let spawn_positions = match stage_manifest.neutral_spawn_positions(config.players.len()) {
+        Ok(positions) => positions,
+        Err(error) => {
+            fail_match(&mut next_state, &error);
+            return;
+        }
+    };
+
     if assets.fighters.len() != config.players.len() {
         fail_match(
             &mut next_state,
@@ -449,7 +462,8 @@ pub fn prepare_match(
         ));
     }
 
-    let session_config = match SessionConfig::from_args(&args, config.players.len()) {
+    let session_player_count = player_count_for_handles(&config.players);
+    let session_config = match SessionConfig::from_args(&args, session_player_count) {
         Ok(config) => config,
         Err(error) => {
             fail_match(
@@ -459,7 +473,7 @@ pub fn prepare_match(
             return;
         }
     };
-    let session = match create_session(&args, config.players.len()) {
+    let session = match create_session(&args, session_player_count) {
         Ok(session) => session,
         Err(error) => {
             fail_match(
@@ -472,12 +486,6 @@ pub fn prepare_match(
 
     let root = commands.spawn((Name::new("Match"), MatchRoot)).id();
 
-    let stage_handle = stage_registry
-        .get(config.stage)
-        .expect("Initialization check should ensure all stages exist");
-    let stage_manifest = stage_manifests
-        .get(&stage_handle)
-        .expect("Initialization check should ensure stage manifests are kept alive");
     stage::spawn_stage(
         &mut commands,
         root,
@@ -487,14 +495,15 @@ pub fn prepare_match(
     );
 
     let mut fighter_roster = Vec::with_capacity(config.players.len());
-    for (index, (player, (scene, animations, attack_scripts, manifest_handle, model_scale, ecb_bone_indices))) in
+
+    for (spawn_index, (player, (scene, animations, attack_scripts, manifest_handle, model_scale, ecb_bone_indices))) in
         config.players.iter().zip(prepared).enumerate()
     {
-        let spawn_x = (index as i32 * 2 + 1 - config.players.len() as i32) * 5;
+        let spawn_point = spawn_positions[spawn_index];
         fighter_roster.push(spawn_fighter(
             &mut commands,
             player.handle,
-            FGVec2::new(FGi32::from_num(spawn_x), FGi32::lit("12.5")),
+            spawn_point,
             manifest_handle.clone(),
             model_scale,
             animations,
@@ -518,12 +527,22 @@ fn fail_match(next_state: &mut NextState<AppState>, message: &str) {
 }
 
 fn valid_player_handles(players: &[MatchPlayer]) -> bool {
-    let mut handles = players
+    if players.is_empty() {
+        return false;
+    }
+
+    let mut handles = players.iter().map(|player| player.handle).collect::<Vec<_>>();
+    handles.sort_unstable();
+    handles.windows(2).all(|handles| handles[0] != handles[1])
+        && handles.last().is_none_or(|handle| *handle != usize::MAX)
+}
+
+fn player_count_for_handles(players: &[MatchPlayer]) -> usize {
+    players
         .iter()
         .map(|player| player.handle)
-        .collect::<Vec<_>>();
-    handles.sort_unstable();
-    handles == (0..players.len()).collect::<Vec<_>>()
+        .max()
+        .map_or(0, |handle| handle + 1)
 }
 
 pub fn cleanup_match(
@@ -590,6 +609,23 @@ mod tests {
         assert!(!valid_player_handles(&players));
     }
 
+    #[test]
+    fn player_handles_may_have_gaps() {
+        let players = [
+            MatchPlayer {
+                handle: 0,
+                fighter: FighterId::TestFighter,
+            },
+            MatchPlayer {
+                handle: 2,
+                fighter: FighterId::TestFighter,
+            },
+        ];
+
+        assert!(valid_player_handles(&players));
+        assert_eq!(player_count_for_handles(&players), 3);
+    }
+
     #[test]
     fn match_rules_reject_zero_limits() {
         assert!(

src/match_runtime.rs

@@ -40,7 +40,12 @@ impl MatchState {
 
         Self {
             elapsed_frames: 0,
-            players: (0..config.players.len())
+            players: (0..config
+                .players
+                .iter()
+                .map(|player| player.handle)
+                .max()
+                .map_or(0, |handle| handle + 1))
                 .map(|_| PlayerMatchState {
                     stocks_remaining,
                     score: 0,

src/replay.rs

@@ -140,7 +140,7 @@ fn validate(replay: &Replay) -> Result<(), String> {
         ));
     }
     if replay.players_are_invalid() {
-        return Err("replay player handles must cover 0..player_count".into());
+        return Err("replay player handles must be unique".into());
     }
     if replay.frames.is_empty() {
         return Err("replay must contain at least one frame".into());
@@ -169,7 +169,16 @@ fn validate(replay: &Replay) -> Result<(), String> {
     if replay
         .frames
         .iter()
-        .any(|frame| frame.inputs.len() != replay.match_config.players.len())
+        .any(|frame| {
+            frame.inputs.len()
+                != replay
+                    .match_config
+                    .players
+                    .iter()
+                    .map(|player| player.handle)
+                    .max()
+                    .map_or(0, |handle| handle + 1)
+        })
     {
         return Err("replay frame input count does not match player count".into());
     }
@@ -185,7 +194,9 @@ impl Replay {
             .map(|player| player.handle)
             .collect();
         handles.sort_unstable();
-        handles != (0..handles.len()).collect::<Vec<_>>()
+        handles.is_empty()
+            || handles.windows(2).any(|handles| handles[0] == handles[1])
+            || handles.last() == Some(&usize::MAX)
     }
 
     fn frame(&self, frame: i32) -> Option<&ReplayFrame> {

src/stage/manifest.rs

@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 
 use bevy_asset_loader::asset_collection::AssetCollection;
 use ron_asset_manager::prelude::RonAsset;
@@ -88,6 +88,10 @@ pub struct StageManifest {
     pub blast_zone_top_left: FGVec2,
     #[reflect(ignore)]
     pub blast_zone_bottom_right: FGVec2,
+
+    #[reflect(ignore)]
+    pub spawn_points: Vec<FGVec2>,
+    pub neutral_spawn_point_sets: Vec<Vec<usize>>
 }
 
 #[derive(Resource)]
@@ -163,6 +167,13 @@ pub fn prepare_stage_manifests(
             );
             return;
         }
+        if let Err(error) = manifest.validate_spawn_points() {
+            fail(
+                &mut next_state,
+                &format!("{:?} has invalid spawn points: {error}", manifest.id),
+            );
+            return;
+        }
         if registry.insert(manifest.id, handle.clone()).is_some() {
             fail(
                 &mut next_state,
@@ -187,6 +198,69 @@ pub fn prepare_stage_manifests(
 }
 
 impl StageManifest {
+    pub fn neutral_spawn_positions(&self, player_count: usize) -> Result<Vec<FGVec2>, String> {
+        if player_count == 0 {
+            return Err("a match must contain at least one player".to_owned());
+        }
+
+        let layout = self
+            .neutral_spawn_point_sets
+            .get(player_count - 1)
+            .ok_or_else(|| format!("no spawn layout for {player_count} players"))?;
+
+        if layout.len() != player_count {
+            return Err(format!(
+                "the {player_count}-player layout contains {} positions",
+                layout.len()
+            ));
+        }
+
+        layout
+            .iter()
+            .map(|&index| {
+                self.spawn_points.get(index).copied().ok_or_else(|| {
+                    format!("the {player_count}-player layout references spawn point {index}")
+                })
+            })
+            .collect()
+    }
+
+    fn validate_spawn_points(&self) -> Result<(), String> {
+        if self.spawn_points.is_empty() {
+            return Err("no spawn points are configured".to_owned());
+        }
+
+        if self.neutral_spawn_point_sets.is_empty() {
+            return Err("no neutral spawn layouts are configured".to_owned());
+        }
+
+        for (layout_index, layout) in self.neutral_spawn_point_sets.iter().enumerate() {
+            let player_count = layout_index + 1;
+            if layout.len() != player_count {
+                return Err(format!(
+                    "the {player_count}-player layout contains {} positions",
+                    layout.len()
+                ));
+            }
+
+            let mut unique_indices = HashSet::with_capacity(layout.len());
+            for &spawn_point_index in layout {
+                if spawn_point_index >= self.spawn_points.len() {
+                    return Err(format!(
+                        "the {player_count}-player layout references spawn point {spawn_point_index}"
+                    ));
+                }
+                if !unique_indices.insert(spawn_point_index) {
+                    return Err(format!(
+                        "the {player_count}-player layout uses spawn point {spawn_point_index} more than once"
+                    ));
+                }
+            }
+        }
+
+        Ok(())
+    }
+
     pub fn to_collision(&self) -> StageCollision {
         let stage_polys: Vec<StagePoly> = self
             .polygons