Add support for drawing a key signature

[scherzo] / pitch.h

diff --git a/pitch.h b/pitch.h
index 657e8fe07f8f291f1a4846c4cf0e596f1f2cdf7d..4467aa86a825c239faa6842819c21d85b58fb1e6 100644 (file)
--- a/pitch.h
+++ b/pitch.h
@@ -54,6 +54,12 @@ 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)
+
 typedef enum pitch_accidental
 {
     PITCH_ACCIDENTAL_DOUBLE_FLAT,
@@ -78,4 +84,28 @@ 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 */