2020.10.19

music_utils.h

@@ -0,0 +1,78 @@
+/* music_utils.h
+ *
+ * Copyright James Allwright 2020
+ *
+ * part of abc2abc/Toadflax
+ *
+ * header file to export basic music manipulation functions.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>
+ */
+#ifndef MUSIC_UTILS_H
+#define MUSIC_UTILS_H 1
+
+extern const char note_array[];
+
+typedef enum noteletter {
+  note_c = 0,
+  note_d = 1,
+  note_e = 2,
+  note_f = 3,
+  note_g = 4,
+  note_a = 5,
+  note_b = 6
+} noteletter_t;
+
+#define MODE_DEFAULT_MAJOR 11
+#define MODE_EXP 10
+
+/* There are only 3 different types of drawn clef. The other clefs are
+ * obtained by drawing one of the basic clefs, but sitting on a different
+ * stave line. For convenience, the abc standard 2.2 numbers these lines
+ * 1 to 5, with the bottom line being 1 and the top line being 5.
+ */
+typedef enum basic_cleftype {
+  basic_clef_treble,
+  basic_clef_bass,
+  basic_clef_alto,
+  basic_clef_undefined, /* for when we didn't find a clef */
+  basic_clef_auto, /* drawing program has free choice of clef */
+  basic_clef_perc, /* percussion */
+  basic_clef_none  /* from abc standard 2.2 what does this mean ? */
+} basic_cleftype_t;
+
+typedef struct new_cleftype {
+  basic_cleftype_t basic_clef;
+  int staveline;
+  int octave_offset;
+  int named;
+} cleftype_t;
+
+extern const char *mode[12];
+extern const int modeshift[12];
+
+/* note operations */
+noteletter_t note_index(char note_ch);
+int semitone_value_for_note(noteletter_t note);
+int semitone_shift_for_acc(char acc);
+void note_for_semitone(int semitones, noteletter_t *note, char *accidental);
+
+/* clef operations */
+void init_new_clef(cleftype_t *new_clef);
+void copy_clef(cleftype_t *target_clef, cleftype_t *source_clef);
+int get_standard_clef (char *name, cleftype_t *new_clef);
+int get_extended_clef_details (char *name, cleftype_t *new_clef);
+int get_clef_name (cleftype_t *new_clef, char *name);
+
+#endif /* MUSIC_UTILS_H 1 */