git.cworth.org Git - scherzo/blob - pitch.h

   1 /* scherzo - Music notation training
   2  *
   3  *      pitch.h - Common structures and functions for pitches, etc.
   4  *
   5  * Copyright © 2010,2013 Carl Worth
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see http://www.gnu.org/licenses/ .
  19  */
  20
  21 #include <stdint.h>
  22
  23 #ifndef PITCH_H
  24 #define PITCH_H
  25
  26 typedef uint32_t pitch_t;
  27
  28 #define PITCH_ACCIDENTAL_SHIFT  (0)
  29 #define PITCH_ACCIDENTAL_MASK   (0x07 << PITCH_ACCIDENTAL_SHIFT)
  30
  31 #define PITCH_NAME_SHIFT        (3)
  32 #define PITCH_NAME_MASK         (0x07 << PITCH_NAME_SHIFT)
  33
  34 #define PITCH_OCTAVE_SHIFT      (6)
  35 #define PITCH_OCTAVE_MASK       (0x07 << PITCH_OCTAVE_SHIFT)
  36
  37 #define PITCH_ACCIDENTAL(pitch) \
  38     (((pitch) & PITCH_ACCIDENTAL_MASK) >> PITCH_ACCIDENTAL_SHIFT)
  39 #define PITCH_NAME(pitch)       \
  40     (((pitch) & PITCH_NAME_MASK) >> PITCH_NAME_SHIFT)
  41 #define PITCH_OCTAVE(pitch)     \
  42     (((pitch) & PITCH_OCTAVE_MASK) >> PITCH_OCTAVE_SHIFT)
  43
  44 #define PITCH(name, accidental, octave)           \
  45     (((octave) << PITCH_OCTAVE_SHIFT)           | \
  46      ((name) << PITCH_NAME_SHIFT)               | \
  47      ((accidental) << PITCH_ACCIDENTAL_SHIFT))
  48
  49 #define PITCH_LITERAL(literal_name, literal_accidental, octave) \
  50     PITCH(PITCH_NAME_##literal_name,                            \
  51           PITCH_ACCIDENTAL_##literal_accidental,                \
  52           octave)
  53
  54 #define PITCH_NATURAL(literal_name, octave) \
  55     PITCH_LITERAL(literal_name, NATURAL, octave)
  56
  57 /* PITCH_CLASS is useful for comparing pitches while ignoring any octave. */
  58 #define PITCH_CLASS(name, accidental) PITCH(name, accidental, 0)
  59
  60 #define PITCH_CLASS_LITERAL(literal_name, literal_accidental) \
  61     PITCH_LITERAL(literal_name, literal_accidental, 0)
  62
  63 typedef enum pitch_accidental
  64 {
  65     PITCH_ACCIDENTAL_DOUBLE_FLAT,
  66     PITCH_ACCIDENTAL_FLAT,
  67     PITCH_ACCIDENTAL_NATURAL,
  68     PITCH_ACCIDENTAL_SHARP,
  69     PITCH_ACCIDENTAL_DOUBLE_SHARP
  70 } pitch_accidental_t;
  71
  72 typedef enum pitch_name
  73 {
  74     PITCH_NAME_C,
  75     PITCH_NAME_D,
  76     PITCH_NAME_E,
  77     PITCH_NAME_F,
  78     PITCH_NAME_G,
  79     PITCH_NAME_A,
  80     PITCH_NAME_B,
  81 } pitch_name_t;
  82
  83 /* Octave numbers are ISO octave numbers [0:8], (so Octave 4 is from
  84  * middle C to the B above middle C).
  85  */
  86
  87 /* Get a string representation of a pitch_t value.
  88  *
  89  * Note: The returned value is static to the pithc_string function and
  90  * may be modified by future calls to pitch_string. So the caller
  91  * should copy the value if needed. */
  92 const char *
  93 pitch_string (pitch_t pitch);
  94
  95 /* Return a new pitch, a number of octaves above 'pitch'
  96  *
  97  * Note: Maximum octave value is 8. A pitch with octave 8 will not be
  98  * raised.
  99  */
 100 pitch_t
 101 pitch_raise_by_octaves (pitch_t pitch, int octaves);
 102
 103 /* Return a new pitch, a number of octaves below 'pitch'
 104  *
 105  * Note: Minimum octave value is 9. A pitch with octave 8 will not be
 106  * lowered.
 107  */
 108 pitch_t
 109 pitch_lower_by_octaves (pitch_t pitch, int octaves);
 110
 111 #endif /* PITCH_H */