1/* $NetBSD: midisynvar.h,v 1.14 2012/04/09 10:18:16 plunky Exp $ */
2
3/*
4 * Copyright (c) 1998 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Lennart Augustsson (augustss@NetBSD.org).
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32#ifndef _SYS_DEV_MIDISYNVAR_H_
33#define _SYS_DEV_MIDISYNVAR_H_
34
35#include "midictl.h"
36
37typedef struct midisyn midisyn;
38
39/*
40 * Important: any synth driver that uses midisyn must set up its methods
41 * structure in a way that refers to members /by name/ and zeroes the rest
42 * (as is the effect of C99 initializers with designators). This discipline
43 * will allow the structure to evolve methods for newly implemented
44 * functionality or to exploit capabilities of new drivers with a minimal
45 * versioning burden. Because midisyn is at present a very rudimentary and
46 * partial implementation, change should be expected in this set of methods.
47 * Do not hesitate to add one in the course of implementing new stuff, as
48 * long as it will be generally useful and there is some reasonable fallback
49 * for drivers without it.
50 */
51struct midisyn_methods {
52 int (*open) (midisyn *, int /* flags */);
53 void (*close) (midisyn *);
54 int (*ioctl) (midisyn *, u_long, void *, int, struct lwp *);
55 /*
56 * allocv(midisyn *ms, uint_fast8_t chan, uint_fast8_t key);
57 * Allocate one of the devices actual voices (stealing one if
58 * necessary) to play note number 'key' (the MIDI note number, not
59 * a frequency) associated with MIDI channel chan. An implementation
60 * might want to choose a voice already last used on chan, to save
61 * shuffling of patches.
62 * One day a variant of this method will probably be needed, with an
63 * extra argument indicating whether a melodic or percussive voice is
64 * wanted.
65 */
66 uint_fast16_t (*allocv) (midisyn *, uint_fast8_t, uint_fast8_t);
67 /*
68 * attackv(midisyn *ms,
69 * uint_fast16_t voice, midipitch_t mp, int16_t level_cB);
70 * Attack the voice 'voice' at pitch 'midipitch' with level 'level_cB'.
71 * The pitch is in MIDI Tuning units and accounts for all of the pitch
72 * adjustment controls that midisyn supports and that the driver has
73 * not reported handling internally. The level is in centibels of
74 * attenuation (0 == no attenuation, full output; reduced levels are
75 * negative) and again accounts for all level adjustments midisyn
76 * supports, except any the driver reports handling itself.
77 * The program used for the voice should be the current program of the
78 * voice's associated MIDI channel, and can be queried with MS_GETPGM.
79 */
80 void (*attackv) (midisyn *, uint_fast16_t, midipitch_t, int16_t);
81 /*
82 * attackv_vel(midisyn *ms, uint_fast16_t voice,
83 * midipitch_t mp, int16_t level_cB, uint_fast8_t vel);
84 * If the driver can do something useful with the voice's attack
85 * velocity, such as vary the attack envelope or timbre, it should
86 * provide this method. Velocity 64 represents the normal attack for
87 * the patch, lower values are softer, higher harder. IF the driver
88 * does not supply this method, midisyn will call the attackv method
89 * instead, and include the velocity in the calculation of level_cB.
90 */
91 void (*attackv_vel) (midisyn *,
92 uint_fast16_t, midipitch_t, int16_t, uint_fast8_t);
93 /*
94 * releasev(midisyn *ms, uint_fast16_t voice, uint_fast8_t vel);
95 * Release the voice 'voice' with release velocity 'vel' where lower
96 * values mean slower decay, 64 refers to the normal decay envelope
97 * for the patch, and higher values mean decay faster.
98 */
99 void (*releasev) (midisyn *, uint_fast16_t, uint_fast8_t);
100 /*
101 * repitchv(midisyn *ms, uint_fast16_t voice, midipitch_t mp);
102 * A driver should provide this method if it is able to change the
103 * pitch of a sounding voice without rearticulating or glitching it.
104 * [not yet implemented in midisyn]
105 */
106 void (*repitchv) (midisyn *, uint_fast16_t, midipitch_t);
107 /*
108 * relevelv(midisyn *ms, uint_fast16_t voice, int16_t level_cB);
109 * A driver should provide this method if it is able to change the
110 * level of a sounding voice without rearticulating or glitching it.
111 * How the driver should adjust 'level_cB' to account for envelope
112 * decay since the initial level is not (quite, yet) specified; the
113 * driver may save the last level it got from midisyn, subtract from
114 * this one, and use the difference to adjust the current level out of
115 * the envelope generator. Or not.... [not yet implemented in midisyn]
116 */
117 void (*relevelv) (midisyn *, uint_fast16_t, int16_t);
118 /*
119 * pgmchg(midisyn *ms, uint_fast8_t chan, uint_fast8_t pgm);
120 * If the driver supports changing programs, it should do whatever it
121 * does AND be sure to store pgm in ms->pgms[chan]. (XXX?)
122 */
123 void (*pgmchg) (midisyn *, uint_fast8_t, uint_fast8_t);
124 /*
125 * ctlnotice(midisyn *ms,
126 * midictl_evt evt, uint_fast8_t chan, uint_fast16_t key);
127 * Reports any of the events on channel 'chan' that midictl (which see)
128 * manages. Return 0 for a particular event if it is not handled by the
129 * driver, nonzero if the driver handles it. Many events can be handled
130 * by midisyn if the driver ignores them, but will be left to the driver
131 * if it returns non-zero. For example, midisyn will usually combine
132 * the volume and expression controllers, plus a note's attack velocity,
133 * into a single 'level' parameter to attackv, but if the driver is
134 * responding to the volume controller on its own, midisyn will leave
135 * that controller out of the combined level computation.
136 * The driver should respond to MIDICTL_RESET events specially. There
137 * are some items of state other than controllers that are specified to
138 * be reset; if the driver keeps such state, it should be reset. The
139 * driver should also midictl_read() all controllers it can respond to,
140 * which will ensure that midictl tracks them.
141 * There are also things that RP-015 specifies do NOT get reset by
142 * the MIDICTL_RESET event. Don't reset those. :)
143 */
144 int (*ctlnotice) (midisyn *, midictl_evt, uint_fast8_t, uint_fast16_t);
145};
146
147struct voice {
148 u_int chan_note; /* channel and note */
149#define MS_CHANNOTE(chan, note) ((chan) * 256 + (note))
150#define MS_GETCHAN(v) ((v)->chan_note >> 8)
151 u_int seqno; /* allocation index (increases with time) */
152 int16_t velcB; /* cB based on attack vel (relevel may need) */
153 u_char inuse;
154};
155
156#define MIDI_MAX_CHANS 16
157
158struct channelstate;
159
160struct midisyn {
161 /* Filled by synth driver */
162 struct midisyn_methods *mets;
163 char name[32];
164 int nvoice;
165 int flags;
166 void *data;
167 kmutex_t *lock;
168
169 /* Set up by midisyn but available to synth driver for reading ctls */
170 /*
171 * Note - there is currently no locking on this structure; if the synth
172 * driver interacts with midictl it should do so synchronously, when
173 * processing a call from midisyn, and not at other times such as upon
174 * an interrupt. (may revisit locking if problems crop up.)
175 */
176 midictl ctl;
177
178 /* Used by midisyn driver */
179 struct voice *voices;
180 u_int seqno;
181 u_int16_t pgms[MIDI_MAX_CHANS]; /* ref'd if driver uses MS_GETPGM */
182 struct channelstate *chnstate;
183};
184
185#define MS_GETPGM(ms, vno) ((ms)->pgms[MS_GETCHAN(&(ms)->voices[vno])])
186
187extern const struct midi_hw_if midisyn_hw_if;
188
189void midisyn_init(midisyn *);
190
191/*
192 * Convert a 14-bit volume or expression controller value to centibels using
193 * the General MIDI formula. The maximum controller value translates to 0 cB
194 * (no attenuation), a half-range controller to -119 cB (level cut by 11.9 dB)
195 * and a zero controller to INT16_MIN. If you are converting a 7-bit value
196 * just shift it 7 bits left first.
197 */
198extern int16_t midisyn_vol2cB(uint_fast16_t);
199
200#endif /* _SYS_DEV_MIDISYNVAR_H_ */
201