xref: /netbsd-src/sys/dev/midisynvar.h (revision 8b0f9554ff8762542c4defc4f70e1eb76fb508fa)
1 /*	$NetBSD: midisynvar.h,v 1.11 2007/03/04 06:01:43 christos 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  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *        This product includes software developed by the NetBSD
21  *        Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #ifndef _SYS_DEV_MIDISYNVAR_H_
40 #define _SYS_DEV_MIDISYNVAR_H_
41 
42 #include "midictl.h"
43 
44 typedef struct midisyn midisyn;
45 
46 /*
47  * Important: any synth driver that uses midisyn must set up its methods
48  * structure in a way that refers to members /by name/ and zeroes the rest
49  * (as is the effect of C99 initializers with designators). This discipline
50  * will allow the structure to evolve methods for newly implemented
51  * functionality or to exploit capabilities of new drivers with a minimal
52  * versioning burden.  Because midisyn is at present a very rudimentary and
53  * partial implementation, change should be expected in this set of methods.
54  * Do not hesitate to add one in the course of implementing new stuff, as
55  * long as it will be generally useful and there is some reasonable fallback
56  * for drivers without it.
57  */
58 struct midisyn_methods {
59 	int  (*open)	(midisyn *, int /* flags */);
60 	void (*close)   (midisyn *);
61 	int  (*ioctl)   (midisyn *, u_long, void *, int, struct lwp *);
62 	/*
63 	 * allocv(midisyn *ms, uint_fast8_t chan, uint_fast8_t key);
64 	 * Allocate one of the devices actual voices (stealing one if
65 	 * necessary) to play note number 'key' (the MIDI note number, not
66 	 * a frequency) associated with MIDI channel chan. An implementation
67 	 * might want to choose a voice already last used on chan, to save
68 	 * shuffling of patches.
69 	 * One day a variant of this method will probably be needed, with an
70 	 * extra argument indicating whether a melodic or percussive voice is
71 	 * wanted.
72 	 */
73 	uint_fast16_t  (*allocv)  (midisyn *, uint_fast8_t, uint_fast8_t);
74 	/*
75 	 * attackv(midisyn *ms,
76 	 *         uint_fast16_t voice, midipitch_t mp, int16_t level_cB);
77 	 * Attack the voice 'voice' at pitch 'midipitch' with level 'level_cB'.
78 	 * The pitch is in MIDI Tuning units and accounts for all of the pitch
79 	 * adjustment controls that midisyn supports and that the driver has
80 	 * not reported handling internally. The level is in centibels of
81 	 * attenuation (0 == no attenuation, full output; reduced levels are
82 	 * negative) and again accounts for all level adjustments midisyn
83 	 * supports, except any the driver reports handling itself.
84 	 * The program used for the voice should be the current program of the
85 	 * voice's associated MIDI channel, and can be queried with MS_GETPGM.
86 	 */
87 	void (*attackv)  (midisyn *, uint_fast16_t, midipitch_t, int16_t);
88 	/*
89 	 * attackv_vel(midisyn *ms, uint_fast16_t voice,
90 	 *             midipitch_t mp, int16_t level_cB, uint_fast8_t vel);
91 	 * If the driver can do something useful with the voice's attack
92 	 * velocity, such as vary the attack envelope or timbre, it should
93 	 * provide this method. Velocity 64 represents the normal attack for
94 	 * the patch, lower values are softer, higher harder. IF the driver
95 	 * does not supply this method, midisyn will call the attackv method
96 	 * instead, and include the velocity in the calculation of level_cB.
97 	 */
98 	void (*attackv_vel) (midisyn *,
99 	                     uint_fast16_t, midipitch_t, int16_t, uint_fast8_t);
100 	/*
101 	 * releasev(midisyn *ms, uint_fast16_t voice, uint_fast8_t vel);
102 	 * Release the voice 'voice' with release velocity 'vel' where lower
103 	 * values mean slower decay, 64 refers to the normal decay envelope
104 	 * for the patch, and higher values mean decay faster.
105 	 */
106 	void (*releasev) (midisyn *, uint_fast16_t, uint_fast8_t);
107 	/*
108 	 * repitchv(midisyn *ms, uint_fast16_t voice, midipitch_t mp);
109 	 * A driver should provide this method if it is able to change the
110 	 * pitch of a sounding voice without rearticulating or glitching it.
111 	 * [not yet implemented in midisyn]
112 	 */
113 	void (*repitchv) (midisyn *, uint_fast16_t, midipitch_t);
114 	/*
115 	 * relevelv(midisyn *ms, uint_fast16_t voice, int16_t level_cB);
116 	 * A driver should provide this method if it is able to change the
117 	 * level of a sounding voice without rearticulating or glitching it.
118 	 * How the driver should adjust 'level_cB' to account for envelope
119 	 * decay since the initial level is not (quite, yet) specified; the
120 	 * driver may save the last level it got from midisyn, subtract from
121 	 * this one, and use the difference to adjust the current level out of
122 	 * the envelope generator. Or not.... [not yet implemented in midisyn]
123 	 */
124 	void (*relevelv) (midisyn *, uint_fast16_t, int16_t);
125 	/*
126 	 * pgmchg(midisyn *ms, uint_fast8_t chan, uint_fast8_t pgm);
127 	 * If the driver supports changing programs, it should do whatever it
128 	 * does AND be sure to store pgm in ms->pgms[chan].  (XXX?)
129 	 */
130 	void (*pgmchg)  (midisyn *, uint_fast8_t, uint_fast8_t);
131 	/*
132 	 * ctlnotice(midisyn *ms,
133 	 *           midictl_evt evt, uint_fast8_t chan, uint_fast16_t key);
134 	 * Reports any of the events on channel 'chan' that midictl (which see)
135 	 * manages. Return 0 for a particular event if it is not handled by the
136 	 * driver, nonzero if the driver handles it. Many events can be handled
137 	 * by midisyn if the driver ignores them, but will be left to the driver
138 	 * if it returns non-zero. For example, midisyn will usually combine
139 	 * the volume and expression controllers, plus a note's attack velocity,
140 	 * into a single 'level' parameter to attackv, but if the driver is
141 	 * responding to the volume controller on its own, midisyn will leave
142 	 * that controller out of the combined level computation.
143 	 *   The driver should respond to MIDICTL_RESET events specially. There
144 	 * are some items of state other than controllers that are specified to
145 	 * be reset; if the driver keeps such state, it should be reset. The
146 	 * driver should also midictl_read() all controllers it can respond to,
147 	 * which will ensure that midictl tracks them.
148 	 *   There are also things that RP-015 specifies do NOT get reset by
149 	 * the MIDICTL_RESET event. Don't reset those. :)
150 	 */
151 	int (*ctlnotice) (midisyn *, midictl_evt, uint_fast8_t, uint_fast16_t);
152 };
153 
154 struct voice {
155 	u_int chan_note;	/* channel and note */
156 #define MS_CHANNOTE(chan, note) ((chan) * 256 + (note))
157 #define MS_GETCHAN(v) ((v)->chan_note >> 8)
158 	u_int seqno;		/* allocation index (increases with time) */
159 	int16_t velcB;		/* cB based on attack vel (relevel may need) */
160 	u_char inuse;
161 };
162 
163 #define MIDI_MAX_CHANS 16
164 
165 struct channelstate;
166 
167 struct midisyn {
168 	/* Filled by synth driver */
169 	struct midisyn_methods *mets;
170 	char name[32];
171 	int nvoice;
172 	int flags;
173 	void *data;
174 
175 	/* Set up by midisyn but available to synth driver for reading ctls */
176 	/*
177 	 * Note - there is currently no locking on this structure; if the synth
178 	 * driver interacts with midictl it should do so synchronously, when
179 	 * processing a call from midisyn, and not at other times such as upon
180 	 * an interrupt. (may revisit locking if problems crop up.)
181 	 */
182 	midictl ctl;
183 
184 	/* Used by midisyn driver */
185 	struct voice *voices;
186 	u_int seqno;
187 	u_int16_t pgms[MIDI_MAX_CHANS]; /* ref'd if driver uses MS_GETPGM */
188 	struct channelstate *chnstate;
189 };
190 
191 #define MS_GETPGM(ms, vno) ((ms)->pgms[MS_GETCHAN(&(ms)->voices[vno])])
192 
193 struct midi_softc;
194 
195 extern const struct midi_hw_if midisyn_hw_if;
196 
197 void	midisyn_attach (struct midi_softc *, midisyn *);
198 
199 /*
200  * Convert a 14-bit volume or expression controller value to centibels using
201  * the General MIDI formula. The maximum controller value translates to 0 cB
202  * (no attenuation), a half-range controller to -119 cB (level cut by 11.9 dB)
203  * and a zero controller to INT16_MIN. If you are converting a 7-bit value
204  * just shift it 7 bits left first.
205  */
206 extern int16_t midisyn_vol2cB(uint_fast16_t);
207 
208 #endif /* _SYS_DEV_MIDISYNVAR_H_ */
209