+/* Determine a chord name (if any) from the current notes pressed */
+
+typedef struct analyzed_pitch {
+ /* Original note being analzyed. */
+ pitch_t pitch;
+
+ /* Absolute pitch (expressed as midi number). */
+ int midi_pitch;
+
+ /* Pitch relative to bass note. */
+ int relative_pitch;
+} analyzed_pitch_t;
+
+static int
+_compare_analyzed_pitch_by_midi_pitch (const void *va, const void *vb)
+{
+ const analyzed_pitch_t *a = va, *b = vb;
+
+ return a->midi_pitch - b->midi_pitch;
+}
+
+static int
+_compare_analyzed_pitch_by_relative_pitch (const void *va, const void *vb)
+{
+ const analyzed_pitch_t *a = va, *b = vb;
+
+ return a->relative_pitch - b->relative_pitch;
+}
+
+typedef struct modified_degree
+{
+ int degree;
+ int modification;
+} modified_degree_t;
+
+static int
+_modified_degree_to_half_steps (const modified_degree_t *degree)
+{
+ int half_steps;
+ int scale_degree = degree->degree;
+
+ /* Restrict to actual degrees within a scale. */
+ if (scale_degree > 7)
+ scale_degree = (scale_degree % 8) + 1;
+
+ /* Number of half steps from root to specified degree within a
+ * diatonic scale. */
+ switch (scale_degree) {
+ case 1:
+ half_steps = 0;
+ break;
+ case 2:
+ half_steps = 2;
+ break;
+ case 3:
+ half_steps = 4;
+ break;
+ case 4:
+ half_steps = 5;
+ break;
+ case 5:
+ half_steps = 7;
+ break;
+ case 6:
+ half_steps = 9;
+ break;
+ case 7:
+ half_steps = 11;
+ break;
+ default:
+ fprintf (stderr, "Internal: Invalid degree %d\n", degree->degree);
+ exit (1);
+ break;
+ }
+
+ return half_steps + degree->modification;
+}
+
+static int
+_chord_signature_matches (analyzed_pitch_t *pitches,
+ int num_pitches,
+ modified_degree_t *degrees,
+ int num_degrees,
+ int inversion,
+ pitch_t *root)
+{
+#define MAX_DEGREES 6
+ int relative_pitches[MAX_DEGREES];
+ int i, root_index;
+
+ assert (num_degrees <= MAX_DEGREES);
+
+ if (num_pitches != num_degrees)
+ return 0;
+
+ if (inversion >= num_degrees)
+ return 0;
+
+ /* We never spell simple intervals as inversions. */
+ if (num_degrees == 2 && inversion > 0)
+ return 0;
+
+ for (i = 0; i < num_degrees; i++) {
+ /* The num_degrees is in the addition just to ensure all
+ * inputs to the modulus operator remain positive. */
+ int index = (i + num_degrees - inversion) % num_degrees;
+
+ /* Again, adding a 12 to keep things positive. */
+ relative_pitches[index] =
+ (12 +
+ _modified_degree_to_half_steps (°rees[i]) -
+ _modified_degree_to_half_steps (°rees[inversion])) % 12;
+
+ }
+
+ for (i = 0; i < num_pitches; i++)
+ if (pitches[i].relative_pitch != relative_pitches[i])
+ return 0;
+
+ root_index = (num_pitches - inversion) % num_pitches;
+ *root = pitches[root_index].pitch;
+
+ return 1;
+}
+
+typedef struct chord_signature
+{
+ int num_degrees;
+ modified_degree_t degrees[MAX_DEGREES];
+ const char *name;
+} chord_signature_t;
+
+/* XXX: The superscript rise value should be relative to the current
+ * font size. Best would be for pango to support this. See:
+ *
+ * https://bugzilla.gnome.org/show_bug.cgi?id=708780
+ *
+ * For now, these are emipirically-derived values that look reasonable
+ * at the default size that score.c is using to draw the staff. If the
+ * user scales the staff up or down then these will look wrong.
+ */
+
+#define SUP "<span font='33' rise='30000'>"
+#define PUS "</span>"
+
+chord_signature_t signatures[] = {
+ /* Octave */
+ { 1, {{1, 0}}, "P8" },
+
+ /* Intervals */
+ { 2, {{1, 0}, {2, -1}}, "m2" },
+ { 2, {{1, 0}, {2, 0}}, "M2" },
+ { 2, {{1, 0}, {3, -1}}, "m3" },
+ { 2, {{1, 0}, {3, 0}}, "M3" },
+ { 2, {{1, 0}, {4, 0}}, "P4" },
+ { 2, {{1, 0}, {5, -1}}, "Tri-tone" },
+ { 2, {{1, 0}, {5, 0}}, "P5" },
+ { 2, {{1, 0}, {6, -1}}, "m6" },
+ { 2, {{1, 0}, {6, 0}}, "M6" },
+ { 2, {{1, 0}, {7, -1}}, "m7" },
+ { 2, {{1, 0}, {7, 0}}, "M7" },
+
+ /* Triads */
+ { 3, {{1, 0}, {4, 0}, {5, 0}}, "sus" },
+ { 3, {{1, 0}, {3, 0}, {5, +1}}, SUP "+" PUS },
+ { 3, {{1, 0}, {3, 0}, {5, 0}}, "" },
+ { 3, {{1, 0}, {3, -1}, {5, 0}}, "m" },
+ { 3, {{1, 0}, {3, -1}, {5, -1}}, "°" },
+ { 3, {{1, 0}, {2, 0}, {5, 0}}, "msus2" },
+
+ /* Seventh chords with no 3rd */
+ { 3, {{1, 0}, {5, +1}, {7, 0}}, SUP "+M7" PUS },
+ { 3, {{1, 0}, {5, +1}, {7, -1}}, SUP "+7" PUS },
+ { 3, {{1, 0}, {5, 0}, {7, 0}}, "M7" },
+ { 3, {{1, 0}, {5, 0}, {7, -1}}, "7" },
+ { 3, {{1, 0}, {5, -1}, {7, -1}}, "7♭5" },
+
+ /* Seventh chords with no 5th */
+ { 3, {{1, 0}, {4, 0}, {7, 0}}, "M7sus" },
+ { 3, {{1, 0}, {4, 0}, {7, -1}}, "7sus" },
+ { 3, {{1, 0}, {3, 0}, {7, 0}}, "M7" },
+ { 3, {{1, 0}, {3, 0}, {7, -1}}, "7" },
+ { 3, {{1, 0}, {3, -1}, {7, 0}}, "m" SUP "M7" PUS },
+ { 3, {{1, 0}, {3, -1}, {7, -1}}, "m7" },
+ { 3, {{1, 0}, {2, 0}, {7, 0}}, "m" SUP "M7" PUS "sus2" },
+ { 3, {{1, 0}, {2, 0}, {7, -1}}, "m7sus2" },
+
+ /* Sixth chords */
+ { 4, {{1, 0}, {4, 0}, {5, 0}, {6, 0}}, "6sus" },
+ { 4, {{1, 0}, {3, 0}, {5, 0}, {6, 0}}, "6" }, /* Ambiguous with m7 */
+ { 4, {{1, 0}, {3, -1}, {5, 0}, {6, 0}}, "m6" },
+ { 4, {{1, 0}, {2, 0}, {5, 0}, {6, 0}}, "m6sus2" },
+
+ /* Seventh chords */
+ { 4, {{1, 0}, {4, 0}, {5, +1}, {7, 0}}, SUP "+M7" PUS "sus" },
+ { 4, {{1, 0}, {4, 0}, {5, +1}, {7, -1}}, SUP "+7" PUS "sus" },
+ { 4, {{1, 0}, {4, 0}, {5, 0}, {7, 0}}, "M7sus" },
+ { 4, {{1, 0}, {4, 0}, {5, 0}, {7, -1}}, "7sus" },
+ { 4, {{1, 0}, {4, 0}, {5, -1}, {7, -1}}, "7♭5sus" },
+ { 4, {{1, 0}, {3, 0}, {5, +1}, {7, 0}}, SUP "+M7" PUS },
+ { 4, {{1, 0}, {3, 0}, {5, +1}, {7, -1}}, SUP "+7" PUS },
+ { 4, {{1, 0}, {3, 0}, {5, 0}, {7, 0}}, "M7" },
+ { 4, {{1, 0}, {3, 0}, {5, 0}, {7, -1}}, "7" },
+ { 4, {{1, 0}, {3, 0}, {5, -1}, {7, -1}}, "7♭5" },
+ { 4, {{1, 0}, {3, -1}, {5, 0}, {7, 0}}, "m" SUP "M7" PUS },
+ { 4, {{1, 0}, {3, -1}, {5, 0}, {7, -1}}, "m7" },
+ { 4, {{1, 0}, {3, -1}, {5, -1}, {7, 0}}, "°" SUP "M7" PUS },
+ { 4, {{1, 0}, {3, -1}, {5, -1}, {7, -1}}, "𝆩" SUP "7" PUS },
+ { 4, {{1, 0}, {3, -1}, {5, -1}, {7, -2}}, "°" SUP "7" PUS },
+ { 4, {{1, 0}, {2, 0}, {5, 0}, {7, 0}}, "m" SUP "M7" PUS "sus2" },
+ { 4, {{1, 0}, {2, 0}, {5, 0}, {7, -1}}, "m7sus2" },
+ { 4, {{1, 0}, {2, 0}, {5, -1}, {7, 0}}, "°" SUP "M7" PUS "sus2" },
+ { 4, {{1, 0}, {2, 0}, {5, -1}, {7, -1}}, "𝆩" SUP "7" PUS "sus2" },
+ { 4, {{1, 0}, {2, 0}, {5, -1}, {7, -2}}, "°" SUP "7" PUS "sus2" }, /* Ambiguous with 7 */
+
+ /* The sorting for chords with degree higher than 9 is funny
+ * to keep the array in degree order after reducing each
+ * degree to an actual scale degree, (9 -> 2, 11 -> 4, 13 ->
+ * 6) */
+
+ /* Ninth chords voiced with no 5th */
+ { 4, {{1, 0}, {9, 0}, {4, 0}, {7, 0}}, "M9sus" },
+ { 4, {{1, 0}, {9, 0}, {4, 0}, {7, -1}}, "9sus" },
+ { 4, {{1, 0}, {9, 0}, {3, 0}, {7, 0}}, "M9" },
+ { 4, {{1, 0}, {9, 0}, {3, 0}, {7, -1}}, "9" },
+ { 4, {{1, 0}, {9, 0}, {3, -1}, {7, 0}}, "m" SUP "M9" PUS },
+ { 4, {{1, 0}, {9, 0}, {3, -1}, {7, -1}}, "m9" },
+ { 4, {{1, 0}, {9, -1}, {3, -1}, {7, -1}}, "m♭9" },
+ { 4, {{1, 0}, {9, 0}, {3, -1}, {6, 0}}, "m6/9" },
+ { 4, {{1, 0}, {9, -1}, {3, -1}, {6, 0}}, "m6/♭9" },
+
+ /* Sixth plus 9 */
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, 0}, {6, 0}}, "6/9" },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, 0}, {6, 0}}, "m6/9" },
+ { 5, {{1, 0}, {9, -1}, {3, -1}, {5, 0}, {6, 0}}, "m6/♭9" },
+
+ /* Seventh plus altered 9 */
+ { 5, {{1, 0}, {9, +1}, {3, 0}, {5, 0}, {7, -1}}, "7♯9" },
+ { 5, {{1, 0}, {9, -1}, {3, 0}, {5, 0}, {7, -1}}, "7♭9" },
+ { 5, {{1, 0}, {9, +1}, {3, 0}, {5, -1}, {7, -1}}, "7♭5♯9" },
+ { 5, {{1, 0}, {9, -1}, {3, 0}, {5, -1}, {7, -1}}, "7♭5♭9" },
+
+ /* Ninth chords */
+ { 5, {{1, 0}, {9, 0}, {4, 0}, {5, +1}, {7, 0}}, SUP "+M9" PUS "sus" },
+ { 5, {{1, 0}, {9, 0}, {4, 0}, {5, +1}, {7, -1}}, SUP "+9" PUS "sus" },
+ { 5, {{1, 0}, {9, 0}, {4, 0}, {5, 0}, {7, 0}}, "M9sus" },
+ { 5, {{1, 0}, {9, 0}, {4, 0}, {5, 0}, {7, -1}}, "9sus" },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, +1}, {7, 0}}, SUP "+M9" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, +1}, {7, -1}}, SUP "+9" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, 0}, {7, 0}}, "M9" },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, 0}, {7, -1}}, "9" },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, 0}, {7, 0}}, "m" SUP "M9" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, 0}, {7, -1}}, "m9" },
+ { 5, {{1, 0}, {9, -1}, {3, -1}, {5, 0}, {7, -1}}, "m♭9" },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, -1}, {7, 0}}, "M9" SUP "♭5" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, 0}, {5, -1}, {7, -1}}, "9" SUP "♭5" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, -1}, {7, 0}}, "m" SUP "M9♭5" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, -1}, {7, -1}}, "𝆩" SUP "9" PUS },
+ { 5, {{1, 0}, {9, -1}, {3, -1}, {5, -1}, {7, -1}}, "𝆩" SUP "♭9" PUS },
+ { 5, {{1, 0}, {9, 0}, {3, -1}, {5, -1}, {7, -2}}, "°" SUP "9" PUS },
+ { 5, {{1, 0}, {9, -1}, {3, -1}, {5, -1}, {7, -2}}, "°" SUP "♭9" PUS },
+
+ /* Eleventh chords */
+ { 6, {{1, 0}, {9, 0}, {3, 0}, {11, 0}, {5, +1}, {7, 0}}, SUP "+M11" PUS },
+ { 6, {{1, 0}, {9, 0}, {3, 0}, {11, 0}, {5, +1}, {7, -1}}, SUP "+11" PUS },
+ { 6, {{1, 0}, {9, 0}, {3, 0}, {11, 0}, {5, 0}, {7, 0}}, "M11" },
+ { 6, {{1, 0}, {9, 0}, {3, 0}, {11, 0}, {5, 0}, {7, -1}}, "11" },
+ { 6, {{1, 0}, {9, 0}, {3, -1}, {11, 0}, {5, 0}, {7, 0}}, "m" SUP "M11" PUS },
+ { 6, {{1, 0}, {9, 0}, {3, -1}, {11, 0}, {5, 0}, {7, -1}}, "m11" },
+ { 6, {{1, 0}, {9, -1}, {3, -1}, {11, 0}, {5, -1}, {7, -1}}, "𝆩" SUP "11" PUS },
+ { 6, {{1, 0}, {9, -1}, {3, -1}, {11, -1}, {5, -1}, {7, -2}}, "°" SUP "11" PUS }
+};
+
+static void
+_spell_chord_by_signature (pitch_group_t *chord,
+ chord_signature_t *signature,
+ pitch_t root)
+{
+ int i, degree, note_half_steps, degree_half_steps;
+
+ for (i = 0; i < chord->num_pitches; i++) {
+ note_half_steps = pitch_from_root_in_half_steps (chord->pitches[i],
+ root);
+ for (degree = 0; degree < signature->num_degrees; degree++) {
+ degree_half_steps = _modified_degree_to_half_steps (&signature->degrees[degree]);
+ if (note_half_steps == degree_half_steps) {
+ chord->pitches[i] = pitch_spell_as_degree (chord->pitches[i],
+ root,
+ signature->degrees[degree].degree);
+ break;
+ }
+ }
+ if (note_half_steps != degree_half_steps) {
+ fprintf (stderr, "Internal error: Chord and degree mis-match\n");
+ exit (1);
+ }
+ }
+}
+
+static void
+_analyze_chord (pitch_group_t *chord,
+ chord_signature_t **signature_ret,
+ pitch_t **root_ret)
+{
+ void *local = talloc_new (NULL);
+ analyzed_pitch_t *pitches;
+ int i, j, num_pitches;
+ int bass_pitch, inversion;
+ pitch_t root;
+ chord_signature_t *match = NULL;
+
+ /* Default to no-match for any early return */
+ *signature_ret = NULL;
+ *root_ret = NULL;
+
+ num_pitches = chord->num_pitches;
+
+ if (chord->num_pitches <= 1)
+ goto DONE;
+
+ pitches = talloc_array (local, analyzed_pitch_t, num_pitches);
+ if (pitches == NULL)
+ goto DONE;
+
+ for (i = 0; i < num_pitches; i++) {
+ pitch_t pitch = chord->pitches[i];
+ pitches[i].pitch = pitch;
+ pitches[i].midi_pitch = pitch_to_midi (pitch);
+ /* Relative pitch will be filled in after sorting. */
+ pitches[i].relative_pitch = 0;
+ }
+
+ /* First, sort by midi pitch to find the bass note. */
+ qsort (pitches, num_pitches, sizeof (analyzed_pitch_t),
+ _compare_analyzed_pitch_by_midi_pitch);
+
+ bass_pitch = pitches[0].midi_pitch;
+
+ /* With the bass note identified, we can find all relative pitches. */
+ for (i = 0; i < num_pitches; i++) {
+ pitches[i].relative_pitch = pitches[i].midi_pitch - bass_pitch;
+ while (pitches[i].relative_pitch >= 12)
+ pitches[i].relative_pitch -= 12;
+ }
+
+ /* Now, sort again by relative pitch. */
+ qsort (pitches, num_pitches, sizeof (analyzed_pitch_t),
+ _compare_analyzed_pitch_by_relative_pitch);
+
+ /* Finally, eliminate all duplicate notes. */
+ for (i = 0; i < num_pitches - 1; i++) {
+ if (pitches[i+1].relative_pitch == pitches[i].relative_pitch) {
+ j = i+1;
+ while (j < num_pitches &&
+ pitches[j].relative_pitch == pitches[i].relative_pitch)
+ {
+ j++;
+ }
+ /* The loop incremented j one past the last
+ * duplicate. Decrement so that it points to the
+ * last duplicate (and is guaranteed to not exceed
+ * the array bounds).*/
+ j--;
+
+ if (j < num_pitches - 1) {
+ memmove (&pitches[i+1], &pitches[j+1],
+ (num_pitches - j) * sizeof (analyzed_pitch_t));
+ }
+
+ num_pitches -= (j - i);
+ }
+ }
+
+ for (inversion = 0; inversion < 4; inversion++) {
+ for (i = 0; i < ARRAY_SIZE (signatures); i++) {
+ if (_chord_signature_matches (pitches, num_pitches,
+ signatures[i].degrees,
+ signatures[i].num_degrees,
+ inversion, &root))
+ {
+ match = &signatures[i];
+ goto HAVE_MATCH;
+ }
+ }
+ }
+HAVE_MATCH:
+
+ if (match) {
+ *signature_ret = match;
+ for (i = 0; i < chord->num_pitches; i++) {
+ if (chord->pitches[i] == root) {
+ *root_ret = &chord->pitches[i];
+ break;
+ }
+ }
+ }
+
+DONE:
+ talloc_free (local);
+}
+
+static void
+pitch_group_init (void *ctx, pitch_group_t *group)
+{
+ group->ctx = ctx;
+ group->pitches = NULL;
+ group->size = 0;
+ group->num_pitches = 0;
+}
+
+static void
+pitch_group_add_pitch (pitch_group_t *group, pitch_t pitch)
+{
+ int i;
+
+ /* Do nothing if pitch is already in group. */
+ for (i = 0; i < group->num_pitches; i++)
+ if (group->pitches[i] == pitch)
+ return;
+
+ group->num_pitches++;
+
+ if (group->num_pitches > group->size) {
+ group->size++;
+ group->pitches = talloc_realloc (group->ctx, group->pitches,
+ pitch_t, group->size);
+
+ if (group->pitches == NULL) {
+ fprintf (stderr, "Out of memory.\n");
+ exit (1);
+ }
+ }
+
+ group->pitches[group->num_pitches - 1] = pitch;
+}
+
+static void
+pitch_group_remove_pitch_at (pitch_group_t *group, int i)
+{
+ if (i > group->num_pitches) {
+ fprintf (stderr, "Internal error: Cannot remove pitch %d from group with only %d %s\n",
+ i, group->num_pitches,
+ group->num_pitches == 1 ? "pitch" : "pitches");
+ exit (1);
+ }
+
+ if (i < group->num_pitches - 1) {
+ memmove (group->pitches + i, group->pitches + i + 1,
+ (group->num_pitches - 1 - i) * sizeof (pitch_t));
+ }
+
+ group->num_pitches--;
+}
+
+/* Remove a 'pitch' from 'group', (including any enharmonic pitch)
+ * See also: pitch_group_remove_pitch
+ */
+static void
+pitch_group_remove_pitch_enharmonic (pitch_group_t *group, pitch_t pitch)
+{
+ int i;
+
+ for (i = 0; i < group->num_pitches; i++)
+ if (pitch_enharmonic_to (group->pitches[i], pitch))
+ pitch_group_remove_pitch_at (group, i);
+}
+
+/* Remove an exactly-matching pitch from 'group'
+ * See also: pitch_group_remove_pitch_enharmonic
+ *
+static void
+pitch_group_remove_pitch (pitch_group_t *group, pitch_t pitch)
+{
+ int i;
+
+ for (i = 0; i < group->num_pitches; i++)
+ if (group->pitches[i] == pitch)
+ pitch_group_remove_pitch_at (group, i);
+}
+*/
+
+/* Remove all pitches from a pitch_group_t */
+static void
+pitch_group_remove_pitches (pitch_group_t *group)
+{
+ talloc_free (group->pitches);
+ pitch_group_init (group->ctx, group);
+}
+
+static void
+scherzo_update_notes_and_chord (scherzo_t *scherzo)
+{
+ void *local = talloc_new (NULL);
+ pitch_group_t *chord;
+ chord_signature_t *signature;
+ char *chord_name = NULL;
+ pitch_t *root;
+ int i;
+
+ /* Remove all notes/chords from score, then add current notes. */
+ score_remove_notes (scherzo->score);
+ score_remove_chords (scherzo->score);
+
+ if (scherzo->pedal_pressed)
+ chord = &scherzo->notes_pedaled;
+ else
+ chord = &scherzo->notes_pressed;
+
+ _analyze_chord (chord, &signature, &root);
+
+ if (signature) {
+ /* Don't print root pitch for octaves and inversions,
+ * (since a pitch name alone looks like a major triad) */
+ if (signature->num_degrees < 3) {
+ /* In fact, don't print anything for octaves and
+ * inversions for now. It leads to a bit of flashing when
+ * playing chords.
+ *
+ * FIXME: What I'd like to have here is a small timeout,
+ * such that names only appear once an interval has been
+ * held for at least 100 ms or so. With that, it would be
+ * nice to display the interval names once again.
+ *
+ chord_name = talloc_strdup (local, signature->name);
+ */
+ } else {
+ _spell_chord_by_signature (&scherzo->notes_pressed,
+ signature, *root);
+ _spell_chord_by_signature (&scherzo->notes_pedaled,
+ signature, *root);
+
+ chord_name = talloc_asprintf (local, "%s%s",
+ pitch_string (*root),
+ signature->name);
+ }
+ } else if (chord->num_pitches > 2) {
+ chord_name = talloc_strdup (local, "?");
+ }
+
+ if (chord_name)
+ scherzo->chord = score_add_chord (scherzo->treble, chord_name);
+
+ for (i = 0; i < scherzo->notes_pressed.num_pitches; i++)
+ {
+ score_add_note (scherzo->score, scherzo->notes_pressed.pitches[i],
+ SCORE_DURATION_WHOLE);
+ }
+
+ for (i = 0; i < scherzo->notes_pedaled.num_pitches; i++)
+ {
+ score_add_note (scherzo->score, scherzo->notes_pedaled.pitches[i],
+ SCORE_DURATION_WHOLE);
+ }
+
+ gtk_widget_queue_draw (scherzo->window);
+
+ talloc_free (local);
+}
+
+static void
+scherzo_set_key (scherzo_t *scherzo, pitch_t pitch)
+{
+ scherzo_key_init (&scherzo->key, pitch);
+ score_set_key (scherzo->score, pitch);
+}
+
+static bool
+pitches_are_diatonic_scale (pitch_t *pitches, int num_pitches)
+{
+ int diatonic_half_steps[7] = {
+ 0, 2, 4, 5, 7, 9, 11
+ };
+ int half_steps;
+ pitch_t root;
+ int i;
+
+ if (num_pitches < 7)
+ return 0;
+
+ root = pitches[0];
+
+ for (i = 0; i < 7; i++) {
+ half_steps = pitch_from_root_in_half_steps (pitches[i], root);
+ if (half_steps != diatonic_half_steps[i])
+ return false;
+ }
+
+ return true;
+}
+
+static void
+scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
+{
+ int i;
+
+ pitch = scherzo_key_spell_pitch (&scherzo->key, pitch);
+
+#define NUM_RECENT_PITCHES 7
+ static pitch_t recent_pitches[NUM_RECENT_PITCHES];
+
+ memmove (recent_pitches, recent_pitches + 1,
+ (NUM_RECENT_PITCHES - 1) * sizeof (pitch_t));
+ recent_pitches[NUM_RECENT_PITCHES - 1] = pitch;
+
+ if (pitches_are_diatonic_scale (recent_pitches, NUM_RECENT_PITCHES)) {
+ scherzo_set_key (scherzo, recent_pitches[0]);
+
+ /* Respell pitch according to new key. */
+ pitch = scherzo_key_spell_pitch (&scherzo->key, pitch);
+ }
+
+ /* Do nothing if this note is already pressed. */
+ for (i = 0; i < scherzo->notes_pressed.num_pitches; i++)
+ if (scherzo->notes_pressed.pitches[i] == pitch)
+ return;
+
+ pitch_group_add_pitch (&scherzo->notes_pressed, pitch);
+
+ if (scherzo->pedal_pressed)
+ pitch_group_add_pitch (&scherzo->notes_pedaled, pitch);
+
+ scherzo_update_notes_and_chord (scherzo);
+}
+
+static void
+scherzo_release_note (scherzo_t *scherzo, pitch_t pitch)
+{
+ pitch = scherzo_key_spell_pitch (&scherzo->key, pitch);
+
+ pitch_group_remove_pitch_enharmonic (&scherzo->notes_pressed, pitch);
+
+ scherzo_update_notes_and_chord (scherzo);
+}
+
+static void
+scherzo_press_note_midi (scherzo_t *scherzo, unsigned char midi_note)
+{
+ scherzo_press_note (scherzo, pitch_from_midi (midi_note));
+}
+
+static void
+scherzo_release_note_midi (scherzo_t *scherzo, unsigned char midi_note)
+{
+ scherzo_release_note (scherzo, pitch_from_midi (midi_note));
+}
+
+static void
+scherzo_press_pedal (scherzo_t *scherzo)
+{
+ int i;
+
+ if (scherzo->pedal_pressed)
+ return;
+
+ scherzo->pedal_pressed = 1;
+
+ /* Copy all pressed notes to pedaled notes */
+ for (i = 0; i < scherzo->notes_pressed.num_pitches; i++)
+ pitch_group_add_pitch (&scherzo->notes_pedaled, scherzo->notes_pressed.pitches[i]);
+}
+
+static void
+scherzo_release_pedal (scherzo_t *scherzo)
+{
+ int i;
+
+ if (! scherzo->pedal_pressed)
+ return;
+
+ /* Remove all previously pedaled notes. */
+ for (i = scherzo->notes_pedaled.num_pitches - 1; i >=0; i--)
+ pitch_group_remove_pitch_at (&scherzo->notes_pedaled, i);
+
+ scherzo->pedal_pressed = 0;
+
+ scherzo_update_notes_and_chord (scherzo);
+}
+
+#if 0
+static void
+_select_challenge (scherzo_t *scherzo)
+{
+ category_t *category_unused;
+ bool_t introduced_unused;
+ item_t *item;
+ challenge_t *challenge = &scherzo->challenge;
+ pitch_name_t pitch_name;
+ int octave;
+ char *s;
+
+ mnemon_select_item (&scherzo->mnemon,
+ &challenge->bin,
+ &challenge->item_index,
+ &category_unused,
+ &introduced_unused);
+
+ item = challenge->bin->items[challenge->item_index];
+
+ s = item->challenge;
+ if (strncmp (s, "treble:", 7) == 0) {
+ s += 7;
+ challenge->staff = scherzo->treble;
+ } else if (strncmp (s, "bass:", 5) == 0) {
+ s += 5;
+ challenge->staff = scherzo->bass;
+ } else {
+ fprintf (stderr,
+ "Malformed staff name: %s (expected 'treble:' or 'bass:')\n",
+ s);
+ exit (1);
+ }
+
+ switch (*s) {
+ case 'C':
+ pitch_name = PITCH_NAME_C;
+ break;
+ case 'D':
+ pitch_name = PITCH_NAME_D;
+ break;
+ case 'E':
+ pitch_name = PITCH_NAME_E;
+ break;
+ case 'F':
+ pitch_name = PITCH_NAME_F;
+ break;
+ case 'G':
+ pitch_name = PITCH_NAME_G;
+ break;
+ case 'A':
+ pitch_name = PITCH_NAME_A;
+ break;
+ case 'B':
+ pitch_name = PITCH_NAME_B;
+ break;
+ default:
+ fprintf (stderr, "Malformed pitch name: %s (expected 'A' - 'G')\n", s);
+ exit (1);
+ }
+ s++;
+
+ if (*s < '0' || *s > '9') {
+ fprintf (stderr, "Malformed octave number: %s (expected '0' - '9')\n", s);
+ exit (1);
+ }
+
+ octave = *s - '0';
+
+ challenge->pitch = PITCH (pitch_name, PITCH_ACCIDENTAL_NATURAL, octave);
+
+ challenge->active = 1;
+ challenge->satisfied = 0;
+ challenge->mistaken = 0;
+}
+
+/* Determine whether the user hit the correct note. */
+static void
+_judge_pitch (scherzo_t *scherzo, pitch_t pitch)
+{
+ challenge_t *challenge = &scherzo->challenge;
+
+ if (! challenge->active)
+ return;
+
+ if (pitch == challenge->pitch)
+ challenge->satisfied = 1;
+ else
+ challenge->mistaken = 1;
+}
+
+/* If the user got the right note (eventually), then score it in
+ * mnemon and show the next note. */
+static void
+_score_challenge (scherzo_t *scherzo)
+{
+ challenge_t *challenge = &scherzo->challenge;
+
+ if (! challenge->active)
+ return;
+
+ if (! challenge->satisfied)
+ return;
+
+ mnemon_score_item (&scherzo->mnemon, challenge->bin, challenge->item_index,
+ ! challenge->mistaken);
+
+ _select_challenge (scherzo);
+}
+#endif
+
+typedef struct
+{
+ scherzo_t *scherzo;
+ int fd;
+} scherzo_midi_closure_t;
+
+static int
+on_midi_input (unused (GIOChannel *channel),
+ unused (GIOCondition condition),
+ void *user_data)
+{
+ scherzo_midi_closure_t *closure = user_data;
+ unsigned char buf[MIDI_BUF_SIZE], *next;
+ scherzo_t *scherzo = closure->scherzo;
+ int fd = closure->fd;
+ ssize_t remaining;
+ snd_seq_event_t event;
+
+ remaining = read (fd, buf, MIDI_BUF_SIZE);
+
+ next = buf;
+ while (remaining) {
+ long consumed;
+
+ consumed = snd_midi_event_encode (scherzo->snd_midi_event,
+ next, remaining, &event);
+
+ remaining -= consumed;
+ next += consumed;
+
+ switch (event.type) {
+ case SND_SEQ_EVENT_NONE:
+ /* Incomplete event. Nothing to do. */
+ break;
+ case SND_SEQ_EVENT_NOTEON:
+ scherzo_press_note_midi (scherzo, event.data.note.note);
+ break;
+ case SND_SEQ_EVENT_NOTEOFF:
+ scherzo_release_note_midi (scherzo, event.data.note.note);
+ break;
+ case SND_SEQ_EVENT_CLOCK:
+ /* Ignore for now as my piano sends a constant stream of these. */
+ break;
+ case SND_SEQ_EVENT_SENSING:
+ /* Ignore for now as my piano sends a constant stream of these. */
+ break;
+ case SND_SEQ_EVENT_CONTROLLER:
+ /* XXX: My piano gives me 64 for the sustain pedal, is
+ * that universal? */
+ if (event.data.control.param == 64) {
+ if (event.data.control.value == 0)
+ scherzo_release_pedal (scherzo);
+ else
+ scherzo_press_pedal (scherzo);
+ } else {
+ fprintf (stderr, "Fixme: Unhandled MIDI Control event (param=%d, value=%d)\n",
+ event.data.control.param, event.data.control.value);
+ }
+ break;
+ default:
+ fprintf (stderr, "Fixme: Do not yet know how to handle MIDI event %d\n",
+ event.type);
+ break;
+ }
+ }
+
+ /* Return TRUE to continue to get called in the future. */
+ return TRUE;
+}
+
+static void *
+listen_to_alsa_midi (void *data)
+{
+ scherzo_midi_closure_t *closure = data;
+ int out_fd = closure->fd;
+ snd_rawmidi_t *midi_in;
+ unsigned char buf[MIDI_BUF_SIZE];
+ ssize_t bytes;
+ int err;
+
+ err = snd_rawmidi_open (&midi_in, NULL, "virtual", 0);
+ if (err) {
+ fprintf (stderr, "Failed to open virtual MIDI handle.");
+ return NULL;
+ }
+
+ while (1) {
+ bytes = snd_rawmidi_read (midi_in, buf, MIDI_BUF_SIZE);
+ write (out_fd, buf, bytes);
+ }
+
+ return NULL;
+}
+