sys/dev/midisynvar.h

   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  *
  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
  37 typedef 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  */
  51 struct 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
 147 struct 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
 158 struct channelstate;
 159
 160 struct 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
 168         /* Set up by midisyn but available to synth driver for reading ctls */
 169         /*
 170          * Note - there is currently no locking on this structure; if the synth
 171          * driver interacts with midictl it should do so synchronously, when
 172          * processing a call from midisyn, and not at other times such as upon
 173          * an interrupt. (may revisit locking if problems crop up.)
 174          */
 175         midictl ctl;
 176
 177         /* Used by midisyn driver */
 178         struct voice *voices;
 179         u_int seqno;
 180         u_int16_t pgms[MIDI_MAX_CHANS]; /* ref'd if driver uses MS_GETPGM */
 181         struct channelstate *chnstate;
 182 };
 183
 184 #define MS_GETPGM(ms, vno) ((ms)->pgms[MS_GETCHAN(&(ms)->voices[vno])])
 185
 186 struct midi_softc;
 187
 188 extern const struct midi_hw_if midisyn_hw_if;
 189
 190 void    midisyn_attach (struct midi_softc *, midisyn *);
 191
 192 /*
 193  * Convert a 14-bit volume or expression controller value to centibels using
 194  * the General MIDI formula. The maximum controller value translates to 0 cB
 195  * (no attenuation), a half-range controller to -119 cB (level cut by 11.9 dB)
 196  * and a zero controller to INT16_MIN. If you are converting a 7-bit value
 197  * just shift it 7 bits left first.
 198  */
 199 extern int16_t midisyn_vol2cB(uint_fast16_t);
 200
 201 #endif /* _SYS_DEV_MIDISYNVAR_H_ */