Co-op matches of editor campaigns

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

src/campaign.rs

@@ -619,13 +619,68 @@ pub fn run_map_seed(run_seed: u32, mission: usize) -> u32 {
 // a mission of an editor campaign: its painted map or a random map (rolled from the run's
 // seed), the goals it can actually have, and its block scripts
 pub fn start_editor_mission(doc: &crate::campaign_doc::MissionDoc, i: usize, run_seed: u32) -> Game {
+    editor_mission_mode(doc, i, run_seed, false)
+}
+
+// the same mission for a co-op match: the other master seats (2, 3, 4) belong to the players, so
+// rival masters of the map are left out (like the built-in co-op missions) and so is the Rivals goal
+pub fn start_editor_coop_mission(doc: &crate::campaign_doc::MissionDoc, i: usize, run_seed: u32) -> Game {
+    editor_mission_mode(doc, i, run_seed, true)
+}
+
+// editor missions that can be played in co-op: the master areas need a map of at least 72x72,
+// and a goal other than beating rival masters
+pub fn is_editor_coop_mission(doc: &crate::campaign_doc::MissionDoc) -> bool {
+    doc.size.0 >= 72 && doc.size.1 >= 72 && crate::campaign_doc::parse_goals(&doc.goals).iter().any(|g| *g != Goal::Rivals)
+}
+
+pub fn editor_coop_indexes(doc: &crate::campaign_doc::CampaignDoc) -> Vec<usize> {
+    doc.missions.iter().enumerate().filter(|(_, m)| is_editor_coop_mission(m)).map(|(i, _)| i).collect()
+}
+
+pub fn next_editor_coop_mission(doc: &crate::campaign_doc::CampaignDoc, i: usize, dir: i32) -> usize {
+    let list = editor_coop_indexes(doc);
+    if list.is_empty() {
+        return 0;
+    }
+    let pos = list.iter().position(|m| *m == i).unwrap_or(0);
+    list[((pos as i32 + dir).rem_euclid(list.len() as i32)) as usize]
+}
+
+// a painted map without its rival masters: their creatures go, their tiles become unowned
+fn remove_rivals(g: &mut Game) {
+    let sides: Vec<u8> = g.rivals.iter().map(|r| r.side).collect();
+    if sides.is_empty() {
+        return;
+    }
+    g.rivals.clear();
+    g.ents.retain(|e| e.hero || !sides.contains(&e.side));
+    let owners: Vec<Owner> = sides.iter().map(|&s| Owner::of_side(s)).collect();
+    for t in g.map.t.iter_mut() {
+        if owners.contains(&t.owner) {
+            t.owner = Owner::None;
+            if t.kind == Kind::Core {
+                t.kind = Kind::Floor;
+            }
+        }
+    }
+    g.recount();
+}
+
+fn editor_mission_mode(doc: &crate::campaign_doc::MissionDoc, i: usize, run_seed: u32, coop: bool) -> Game {
     use crate::campaign_doc::MapDoc;
+    let generated = || start_mission_def(&generated_def(doc, run_map_seed(run_seed, i)), i, None, coop);
     let mut g = match &doc.map {
         MapDoc::Fixed { game } => match load_fixed_map(game) {
-            Some(g) => g,
-            None => start_mission_def(&generated_def(doc, run_map_seed(run_seed, i)), i, None, false),
+            Some(mut g) => {
+                if coop {
+                    remove_rivals(&mut g);
+                }
+                g
+            }
+            None => generated(),
         },
-        MapDoc::Random => start_mission_def(&generated_def(doc, run_map_seed(run_seed, i)), i, None, false),
+        MapDoc::Random => generated(),
     };
     g.msgs.clear();
     g.state = 0;