App 2.44.0: the pumpkin light follows the kick drum, behind a switch

MusicPulse reads 40-120 Hz and lights only on jumps of the bass, so
held notes and bass lines stay dark. Settings gets "Pumpkin light
follows the music" (Halloween only, off by default); off, the audio
analyser never starts.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

app/build.gradle

@@ -34,8 +34,8 @@ android {
         applicationId "com.stinnesbeck.nilsmg4"
         minSdk 27
         targetSdk 36
-        versionCode 158
-        versionName "2.43.5"
+        versionCode 159
+        versionName "2.44.0"
 
         // Nothing about the server ships in the APK: its URL and ingest token are entered in
         // the app's Server tab (ServerConfig), and the database is only reachable by the server.

app/src/main/java/com/evsuite/abrp/MainActivity.java

@@ -215,6 +215,8 @@ public class MainActivity extends AppCompatActivity {
 
     /** Whether the Overview hides the navigation (the button in the navigation's header). */
     static final String PREF_OVERVIEW_FULLSCREEN = "overview_fullscreen";
+    /** The Halloween pumpkin's light follows the music; off by default, so the analyser stays off. */
+    static final String PREF_MUSIC_LIGHT = "music_light";
 
     /** True while the Overview is full screen: the navigation hidden, the edge swipe armed. */
     private boolean overviewFull;
@@ -1223,6 +1225,12 @@ public class MainActivity extends AppCompatActivity {
         bindDriveMode();
         bindOverviewStyle();
         bindAccentColor();
+        SwitchMaterial musicLight = settingsPane.findViewById(R.id.music_light_switch);
+        musicLight.setChecked(prefs.getBoolean(PREF_MUSIC_LIGHT, false));
+        musicLight.setOnCheckedChangeListener((btn, checked) -> {
+            prefs.edit().putBoolean(PREF_MUSIC_LIGHT, checked).apply();
+            updateMusicTap();
+        });
         fullScreenSwitch = settingsPane.findViewById(R.id.full_screen_switch);
         fullScreenSwitch.setChecked(UploadSettings.fullScreen(prefs));
         fullScreenSwitch.setOnCheckedChangeListener((btn, checked) -> {
@@ -1761,10 +1769,14 @@ public class MainActivity extends AppCompatActivity {
         updateMusicTap();
     }
 
-    /** The pumpkin listens only while it can be seen: the app in front, on the Overview, in Halloween. */
+    /**
+     * The pumpkin listens only while it can be seen (the app in front, on the Overview, in
+     * Halloween) and only when "Pumpkin light follows the music" is on.
+     */
     private void updateMusicTap() {
         ViewPager2 pager = findViewById(R.id.content);
         musicTap.setRunning(inFront && overviewStyle() == OverviewStyle.HALLOWEEN
+                && prefs.getBoolean(PREF_MUSIC_LIGHT, false)
                 && pager != null && pager.getCurrentItem() == 0);
     }
 
@@ -1828,6 +1840,9 @@ public class MainActivity extends AppCompatActivity {
         TextView note = settingsPane.findViewById(R.id.accent_note);
         note.setVisibility(style.usesAccent ? View.GONE : View.VISIBLE);
         note.setText(getString(R.string.accent_not_used, styleLabels()[style.ordinal()]));
+        int music = style == OverviewStyle.HALLOWEEN ? View.VISIBLE : View.GONE;
+        settingsPane.findViewById(R.id.music_light_switch).setVisibility(music);
+        settingsPane.findViewById(R.id.music_light_hint).setVisibility(music);
     }
 
     /** The drop-down's labels, by {@link OverviewStyle} ordinal. */

app/src/main/java/com/evsuite/abrp/MusicPulse.java

@@ -2,32 +2,45 @@ package com.evsuite.abrp;
 
 /**
  * How strongly the Halloween pumpkin's light answers the music at this moment, from 0 to 1, out of
- * the bass the audio analyser reports. What counts is the beat, not the loudness: each reading is
- * placed between the bass's recent average and its recent peak, so quiet and loud songs both
- * pulse and a steady hum settles at nothing. It rises fast and falls slowly, as a flame does. No
- * reading or silence falls back to 0, so without music the light stays as it is. Android-free and
- * unit-tested.
+ * the kick drum's band the audio analyser reports. What counts is the hit, not the loudness: only
+ * a jump of the bass since the last reading lights it, measured against the biggest jumps of the
+ * last seconds, so quiet and loud songs both flash, and a held bass note or a steady hum does not.
+ * Jumps that are small against the bass's own level (a swelling note, noise) are ignored. It
+ * flares at once and dies down within a beat, as a flame does. No reading or silence falls back to
+ * 0, so without music the light stays as it is. Android-free and unit-tested.
  */
 final class MusicPulse {
 
     /** Below this the bass counts as silence. */
     static final float SILENT = 0.005f;
-    private static final float RISE_S = 0.03f, FALL_S = 0.25f, AVERAGE_S = 2f, PEAK_S = 4f;
+    /** The kick drum's band, in Hz, that {@link MusicTap} reads. */
+    static final float FROM_HZ = 40f, TO_HZ = 120f;
+    private static final float FALL_S = 0.2f, AVERAGE_S = 2f, PEAK_S = 4f;
+    /** A jump below this share of the recent biggest one lights nothing. */
+    private static final float THRESHOLD = 0.2f;
+    /** A jump has to be at least this share of the bass's average level to count at all. */
+    private static final float LEVEL_SHARE = 0.5f;
 
-    private float average, peak, pulse;
+    private float last, average, peakJump, pulse;
 
     /** One reading, {@code seconds} after the last; null when it failed. Returns the new pulse. */
     float update(Float bass, float seconds) {
         float target = 0f;
         if (bass == null || bass.isNaN() || bass < SILENT) {
+            last = 0f;
             average = 0f;
-            peak = 0f;
+            peakJump = 0f;
         } else {
+            float jump = Math.max(0f, bass - last);
+            last = bass;
             average = average == 0f ? bass : average + (bass - average) * share(seconds, AVERAGE_S);
-            peak = Math.max(bass, peak - peak * share(seconds, PEAK_S));
-            if (peak > average) target = Math.max(0f, Math.min(1f, (bass - average) / (peak - average)));
+            peakJump = Math.max(jump, peakJump - peakJump * share(seconds, PEAK_S));
+            float reference = Math.max(peakJump, average * LEVEL_SHARE);
+            if (reference > 0f) {
+                target = Math.max(0f, Math.min(1f, (jump / reference - THRESHOLD) / (1f - THRESHOLD)));
+            }
         }
-        pulse += (target - pulse) * share(seconds, target > pulse ? RISE_S : FALL_S);
+        pulse = target > pulse ? target : pulse + (target - pulse) * share(seconds, FALL_S);
         if (pulse < 0.005f) pulse = 0f;
         return pulse;
     }

app/src/main/java/com/evsuite/abrp/MusicTap.java

@@ -7,9 +7,9 @@ import android.media.audiofx.Visualizer;
 
 /**
  * Listens to what the head unit plays for the Halloween pumpkin's light: Android's audio analyser
- * on the output mix, its bass read 25 times a second on a thread of its own, made into a
+ * on the output mix, its kick-drum band read 25 times a second on a thread of its own, made into a
  * {@link MusicPulse}. Runs only while MainActivity says so (the style on screen, the app in
- * front). Levels only: no sound is kept and no microphone used. Where the analyser hears nothing
+ * front, and "Pumpkin light follows the music" on). Levels only: no sound is kept and no microphone used. Where the analyser hears nothing
  * (the radio) or is not available, the pulse stays 0 and the pumpkin burns as usual.
  */
 final class MusicTap {
@@ -64,7 +64,7 @@ final class MusicTap {
                 boolean read = analyser.getFft(fft) == Visualizer.SUCCESS;
                 failures = read ? 0 : failures + 1;
                 long now = System.nanoTime();
-                float value = music.update(read ? SoundLevels.band(fft, rateHz, 20f, 250f) : null, (now - last) / 1e9f);
+                float value = music.update(read ? SoundLevels.band(fft, rateHz, MusicPulse.FROM_HZ, MusicPulse.TO_HZ) : null, (now - last) / 1e9f);
                 last = now;
                 if (worker == me) pulse = value;
             }

app/src/main/res/layout-w1000dp/pane_settings.xml

@@ -26,6 +26,9 @@
                     </LinearLayout>
                 </LinearLayout>
                 <TextView android:id="@+id/accent_note" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp" android:textAppearance="@style/Text.EV.Secondary" android:visibility="gone" />
+                <!-- Only Halloween listens to the music. -->
+                <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/music_light_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_music_light" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" android:visibility="gone" />
+                <TextView android:id="@+id/music_light_hint" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_music_light" android:textAppearance="@style/Text.EV.Secondary" android:visibility="gone" />
                 <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:baselineAligned="false">
                     <LinearLayout android:layout_width="0dp" android:layout_weight="1" android:layout_height="wrap_content" android:layout_marginEnd="12dp" android:orientation="vertical">
                         <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_tire_unit" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="8dp" />

app/src/main/res/layout/pane_settings.xml

@@ -17,6 +17,9 @@
                 <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/accent_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />
             </com.google.android.material.textfield.TextInputLayout>
             <TextView android:id="@+id/accent_note" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="4dp" android:textAppearance="@style/Text.EV.Secondary" android:visibility="gone" />
+            <!-- Only Halloween listens to the music. -->
+            <com.google.android.material.switchmaterial.SwitchMaterial android:id="@+id/music_light_switch" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:text="@string/label_music_light" android:textAppearance="@style/Text.EV.Body" android:paddingTop="8dp" android:paddingBottom="8dp" app:useMaterialThemeColors="true" app:thumbTint="@color/switch_thumb" app:trackTint="@color/switch_track" android:textColor="@color/ev_text_primary" android:visibility="gone" />
+            <TextView android:id="@+id/music_light_hint" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/hint_music_light" android:textAppearance="@style/Text.EV.Secondary" android:visibility="gone" />
             <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:text="@string/label_tire_unit" android:textAppearance="@style/Text.EV.Body" android:layout_marginTop="20dp" />
             <com.google.android.material.textfield.TextInputLayout style="@style/Widget.EV.Dropdown" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="12dp">
                 <com.google.android.material.textfield.MaterialAutoCompleteTextView android:id="@+id/tire_unit_choices" android:layout_width="match_parent" android:layout_height="wrap_content" android:minHeight="72dp" android:inputType="none" android:textSize="20sp" app:simpleItemLayout="@layout/dropdown_item" />

app/src/main/res/values/strings.xml

@@ -129,6 +129,8 @@
     <string name="overview_style_scifi">Sci-fi</string>
     <string name="overview_style_cartoon">Cartoon</string>
     <string name="overview_style_mg">MG</string>
+    <string name="label_music_light">Pumpkin light follows the music</string>
+    <string name="hint_music_light">Flares on the kick drum over Bluetooth or CarPlay, not the radio. Levels only, no sound kept.</string>
     <string name="accent_not_used">%1$s has its own colours, and the app takes them on. To change the accent colour, pick a style that uses it.</string>
     <string name="overview_fullscreen_enter">Overview full screen: hide the navigation</string>
     <string name="overview_fullscreen_exit">Show the navigation again</string>

app/src/test/java/com/evsuite/abrp/MusicPulseTest.java

@@ -36,6 +36,45 @@ public class MusicPulseTest {
         assertEquals(0f, last, 0f);
     }
 
+    @Test
+    public void aHeldBassNoteLightsOnlyItsStart() {
+        MusicPulse p = new MusicPulse();
+        for (int i = 0; i < 50; i++) p.update(0.05f, STEP);
+        assertTrue(p.update(0.4f, STEP) > 0.8f);
+        float last = 1f;
+        for (int i = 0; i < 25; i++) last = p.update(0.4f, STEP);
+        assertEquals(0f, last, 0f);
+    }
+
+    @Test
+    public void aWobblingBassLineStaysDark() {
+        MusicPulse p = new MusicPulse();
+        for (int i = 0; i < 50; i++) p.update(0.3f, STEP);
+        float top = 0f;
+        for (int i = 0; i < 200; i++) top = Math.max(top, p.update(i % 3 == 0 ? 0.33f : 0.3f, STEP));
+        assertEquals(0f, top, 0f);
+    }
+
+    @Test
+    public void aSwellingNoteStaysDark() {
+        MusicPulse p = new MusicPulse();
+        for (int i = 0; i < 50; i++) p.update(0.1f, STEP);
+        float top = 0f;
+        for (int i = 0; i < 100; i++) top = Math.max(top, p.update(0.1f + i * 0.004f, STEP));
+        assertEquals(0f, top, 0f);
+    }
+
+    @Test
+    public void aKickOverABassLineLights() {
+        MusicPulse p = new MusicPulse();
+        float top = 0f;
+        for (int i = 0; i < 300; i++) {
+            float v = p.update(i % 12 == 0 ? 0.6f : (i % 3 == 0 ? 0.33f : 0.3f), STEP);
+            if (i > 100) top = Math.max(top, v);
+        }
+        assertTrue("a kick lights it, got " + top, top > 0.8f);
+    }
+
     @Test
     public void quietAndLoudSongsPulseAlike() {
         assertEquals(beatOf(0.5f), beatOf(0.05f), 0.02f);