Music: six more dungeon pieces and six surface pieces with flute, harp, birdsong and wind

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

src/main.rs

@@ -487,6 +487,19 @@ impl MusicDirector {
             }
             n >= 4
         };
+        // the camera looks at the land above ground: the music of the surface
+        let above = {
+            let (cx, cz) = (cam.0 as i32, cam.1 as i32);
+            let mut n = 0;
+            for y in (cz - 4..=cz + 4).step_by(2) {
+                for x in (cx - 4..=cx + 4).step_by(2) {
+                    if map::inb(x, y) && g.map.sky(map::idx(x, y)) {
+                        n += 1;
+                    }
+                }
+            }
+            n >= 13
+        };
         let want = if title {
             C::Title
         } else if g.state == 1 {
@@ -508,11 +521,24 @@ impl MusicDirector {
         } else {
             C::Build
         };
-        let rotate = matches!(want, C::Build | C::Title) && self.current == Some(want) && audio::music_loops() >= 2;
+        let want = match want {
+            C::Battle if above => C::SurfaceBattle,
+            C::Build | C::Torture | C::Temple if above => C::Surface,
+            w => w,
+        };
+        let rotate = matches!(want, C::Build | C::Title | C::Surface) && self.current == Some(want) && audio::music_loops() >= 2;
         if self.current != Some(want) || rotate || audio::current_track().is_none() {
+            let before = self.current;
             self.current = Some(want);
             let t = self.pick(want);
-            let fade = if matches!(want, C::Victory | C::Defeat) { 1.0 } else { 2.5 };
+            // between the dungeon and the surface the music changes slowly
+            let fade = if matches!(want, C::Victory | C::Defeat) {
+                1.0
+            } else if matches!((before, want), (Some(C::Surface | C::SurfaceBattle), _) | (_, C::Surface | C::SurfaceBattle)) {
+                4.0
+            } else {
+                2.5
+            };
             audio::play_music(t, fade);
         }
     }