X-Git-Url: https://git.cworth.org/git?a=blobdiff_plain;f=pitch.h;h=3d1dd2e125b98cda6cc4c2ecfe150c54278258db;hb=45d36bd8372f38186ceebf74b48f1a67bd67c573;hp=657e8fe07f8f291f1a4846c4cf0e596f1f2cdf7d;hpb=e77d712bf9f99c3d95f909621ae177b9f8175163;p=scherzo

diff --git a/pitch.h b/pitch.h
index 657e8fe..3d1dd2e 100644
--- a/pitch.h
+++ b/pitch.h
@@ -54,6 +54,14 @@ typedef uint32_t pitch_t;
 #define PITCH_NATURAL(literal_name, octave) \
     PITCH_LITERAL(literal_name, NATURAL, octave)
 
+/* PITCH_CLASS is useful for comparing pitches while ignoring any octave. */
+#define PITCH_CLASS(name, accidental) PITCH(name, accidental, 0)
+
+#define PITCH_CLASS_LITERAL(literal_name, literal_accidental) \
+    PITCH_LITERAL(literal_name, literal_accidental, 0)
+
+#define PITCH_NOT_A_PITCH ((pitch_t) -1)
+
 typedef enum pitch_accidental
 {
     PITCH_ACCIDENTAL_DOUBLE_FLAT,
@@ -78,4 +86,28 @@ typedef enum pitch_name
  * middle C to the B above middle C).
  */
 
+/* Get a string representation of a pitch_t value.
+ *
+ * Note: The returned value is static to the pithc_string function and
+ * may be modified by future calls to pitch_string. So the caller
+ * should copy the value if needed. */
+const char *
+pitch_string (pitch_t pitch);
+
+/* Return a new pitch, a number of octaves above 'pitch'
+ *
+ * Note: Maximum octave value is 8. A pitch with octave 8 will not be
+ * raised.
+ */
+pitch_t
+pitch_raise_by_octaves (pitch_t pitch, int octaves);
+
+/* Return a new pitch, a number of octaves below 'pitch'
+ *
+ * Note: Minimum octave value is 9. A pitch with octave 8 will not be
+ * lowered.
+ */
+pitch_t
+pitch_lower_by_octaves (pitch_t pitch, int octaves);
+
 #endif /* PITCH_H */