game_data: DemoMessage loader — the dialogue backbone

Decode the message tables (schema b412e6d8) into dialogue lines: each
`Message_NNN` sub-record → a DemoMessage with the speaker, portrait
(face), voice-clip token, and caption page text-keys. Fields are found
by prefix (Character*/Face*/VOICE_*/id-prefixed pages), so the
positional / first-record-defines-schema layout doesn't matter.

10,263 lines parse; ~815 name an explicit speaker (the rest are system /
continuation lines — left unattributed rather than guessed). Paired with
localization::TextIndex the attributed ones read straight out — e.g.
KATANA [VOICE_RHIN_000] "Ellen, get back into formation!". The
voice-clip token ties each line to its audio bank, closing the loop with
the cutscene-voice work. +1 test; example `dialogue` prints
speaker + clip + resolved text.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

crates/sylpheed-formats/examples/dialogue.rs

@@ -0,0 +1,13 @@
+use sylpheed_formats::{game_data, localization::TextIndex, PakArchive};
+fn main(){
+    let disc=std::env::var("SYLPHEED_DISC").unwrap();
+    let pak=PakArchive::open(format!("{disc}/dat/GP_MAIN_GAME_E.pak")).unwrap();
+    let text=TextIndex::build(&pak);
+    let msgs=game_data::load_demo_messages(&pak);
+    println!("{} dialogue lines total\n", msgs.len());
+    for m in msgs.iter().filter(|m|m.character.is_some()&&!m.page_keys.is_empty()).take(8){
+        let who=m.character.as_deref().unwrap_or("?").trim_start_matches("Character");
+        let line:String=m.page_keys.iter().filter_map(|k|text.get(k)).collect::<Vec<_>>().join(" ");
+        println!("  {who:10} [{}]  “{}”", m.voice_clip.as_deref().unwrap_or("-"), line.chars().take(64).collect::<String>());
+    }
+}

crates/sylpheed-formats/src/game_data.rs

@@ -37,6 +37,8 @@ pub mod schema {
     pub const CHARACTER: u32 = 0xbd86_d41c;
     /// Stage resource manifest — per mission: location, phases, resource tables.
     pub const STAGE: u32 = 0x3c9a_e32e;
+    /// Message / demo dialogue — per line: speaker, portrait, voice clip, pages.
+    pub const MESSAGE: u32 = 0xb412_e6d8;
 }
 
 /// Parse a numeric field value, tolerating a trailing `f`/`F` (e.g. `"3.0f"`).
@@ -514,6 +516,63 @@ pub fn load_squadrons(pak: &PakArchive) -> Vec<Squadron> {
     out
 }
 
+// ── Demo message / dialogue line ────────────────────────────────────────────────
+
+/// One dialogue line (schema [`MESSAGE`](schema::MESSAGE)): who speaks, with which
+/// portrait and voice clip, and the text-key(s) of its caption pages. Resolve the
+/// page keys against a [`crate::localization::TextIndex`] for the words, and the
+/// voice clip against the movie-voice banks for the audio.
+#[derive(Debug, Clone)]
+pub struct DemoMessage {
+    /// Line id, e.g. `MSG_VOICE_A_007`.
+    pub id: String,
+    /// Speaker (`CharacterRAYMOND`) when the line names one; many system /
+    /// continuation lines are unattributed (`None`).
+    pub character: Option<String>,
+    /// Portrait / emotion (`FaceRAYMOND_07`).
+    pub face: Option<String>,
+    /// Voice clip token (`VOICE_A_007`).
+    pub voice_clip: Option<String>,
+    /// Caption page text keys (`MSG_VOICE_A_007_000_00`, …) — resolve for the text.
+    pub page_keys: Vec<String>,
+}
+
+/// Load every dialogue line from a pak. Each `Message_NNN` sub-record within the
+/// message blobs becomes one [`DemoMessage`]; fields are found by prefix, so the
+/// positional/defaulted layout doesn't matter.
+pub fn load_demo_messages(pak: &PakArchive) -> Vec<DemoMessage> {
+    let is_marker = |s: &str| {
+        s.strip_prefix("Message_").is_some_and(|n| !n.is_empty() && n.bytes().all(|b| b.is_ascii_digit()))
+    };
+    let mut out = Vec::new();
+    for e in pak.entries() {
+        let Ok(b) = pak.read(e) else { continue };
+        let Ok(o) = IdxdObject::parse(&b) else { continue };
+        if o.schema_hash != schema::MESSAGE {
+            continue;
+        }
+        let t = o.tokens();
+        let marks: Vec<usize> = t.iter().enumerate().filter(|(_, s)| is_marker(s)).map(|(i, _)| i).collect();
+        for (k, &m) in marks.iter().enumerate() {
+            let end = marks.get(k + 1).copied().unwrap_or(t.len());
+            let slice = &t[m + 1..end];
+            let Some(id) = slice.first().cloned() else { continue };
+            out.push(DemoMessage {
+                character: slice.iter().find(|s| s.starts_with("Character")).cloned(),
+                face: slice.iter().find(|s| s.starts_with("Face")).cloned(),
+                voice_clip: slice.iter().find(|s| s.starts_with("VOICE_")).cloned(),
+                page_keys: slice
+                    .iter()
+                    .filter(|s| s.len() > id.len() && s.starts_with(&id) && s[id.len()..].starts_with('_'))
+                    .cloned()
+                    .collect(),
+                id,
+            });
+        }
+    }
+    out
+}
+
 // ── Generic record access (any of the ~105 schemas) ─────────────────────────────
 
 /// A generically-decoded IDXD record: its table name, schema id, identity, and
@@ -668,6 +727,22 @@ mod tests {
         assert!(rhino.members.iter().all(|m| m.contains("DeltaSaber")));
     }
 
+    #[test]
+    fn loads_demo_messages() {
+        let Some(pak) = pak() else { return };
+        let msgs = load_demo_messages(&pak);
+        assert!(msgs.len() > 200, "expected many dialogue lines, got {}", msgs.len());
+        // Most lines are `MSG_*` ids with a speaker; page keys extend the id.
+        let msg_ids = msgs.iter().filter(|m| m.id.starts_with("MSG_")).count();
+        assert!(msg_ids > msgs.len() * 9 / 10, "{msg_ids}/{}", msgs.len());
+        // Attributed dialogue (an explicit speaker) is a minority — most lines are
+        // unattributed system/continuation messages — but there are hundreds.
+        let attributed = msgs.iter().filter(|m| m.character.is_some()).count();
+        assert!(attributed > 500, "attributed lines: {attributed}");
+        let m = msgs.iter().find(|m| m.character.is_some() && !m.page_keys.is_empty()).unwrap();
+        assert!(m.page_keys.iter().all(|k| k.starts_with(&m.id)));
+    }
+
     #[test]
     fn generic_records_read_any_schema() {
         let Some(pak) = pak() else { return };