aboutsummaryrefslogtreecommitdiff
path: root/guile/starlet/midi-control/base.scm
blob: fece2bee6596f2ea184113dd2cfd19a2d1dc5680 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
(define-module (starlet midi-control base)
  #:use-module (oop goops)
  #:use-module (ice-9 atomic)
  #:use-module (ice-9 threads)
  #:use-module (ice-9 binary-ports)
  #:use-module (srfi srfi-1)
  #:export (start-midi-control
            get-cc-value
            scale-127-100
            send-note-on
            send-note-off
            register-midi-note-callback!
            register-midi-cc-callback!
            remove-midi-callback!))


(define cc-arrays (make-atomic-box '()))
(define callback-list (make-atomic-box '()))
(define send-queue (make-atomic-box '()))


(define-class <midi-callback> (<object>)

  (type
   #:init-keyword #:type
   #:getter get-type)

  (channel
   #:init-keyword #:channel
   #:getter get-channel)

  (note-or-cc-number
   #:init-keyword #:note-or-cc-number
   #:getter get-note-or-cc-number)

  (callback
   #:init-keyword #:func
   #:getter get-callback-func))


(define (register-midi-callback! type
                                 channel
                                 note-or-cc-number
                                 func)
  (let ((new-callback (make <midi-callback>
                        #:type type
                        #:channel (if channel channel default-channel)
                        #:note-or-cc-number note-or-cc-number
                        #:func func)))
    (atomic-box-set! callback-list
                     (cons new-callback
                           (atomic-box-ref callback-list)))
    new-callback))


(define* (register-midi-note-callback!
          #:key (channel #f) (note-number 1) (func #f))
  (register-midi-callback! 'note channel note-number func))


(define* (register-midi-cc-callback!
          #:key (channel #f) (cc-number 1) (func #f))
  (register-midi-callback! 'cc channel cc-number func))


(define (remove-midi-callback! callback)
  (atomic-box-set! callback-list
                   (remove (lambda (a)
                             (eq? callback a))
                           (atomic-box-ref callback-list))))


(define enqueue-midi-bytes!
  (lambda bytes
    (unless (eq? (atomic-box-compare-and-swap! send-queue '() bytes)
                 '())
      (apply enqueue-midi-bytes! bytes))))


(define* (send-note-on note
                       #:key (channel #f))
  (enqueue-midi-bytes! (+ #b10010000
                          (if channel channel default-channel))
                       note
                       127))


(define* (send-note-off note
                        #:key (channel #f))
  (enqueue-midi-bytes! (+ #b10000000
                          (if channel channel default-channel))
                       note
                       0))


(define (all-notes-off! channel)
  (let again ((l 0))
    (enqueue-midi-bytes! (+ #b10000000 channel) l 0)
    (unless (= l 127)
      (again (+ l 1)))))


(define (ensure-cc-array channel)
  (let ((old-list (atomic-box-ref cc-arrays)))
    (unless (assq channel old-list)
      (unless (eq?
               old-list
               (atomic-box-compare-and-swap! cc-arrays
                                             old-list
                                             (acons channel
                                                    (make-vector 128 #f)
                                                    old-list)))
        ;; CAS failed - try again
        (ensure-cc-array channel)))))


(define (check-cc-callbacks channel cc-number old-val new-val)
  (for-each (lambda (a) ((get-callback-func a) old-val new-val))
            (filter (lambda (a)
                      (and (eq? cc-number (get-note-or-cc-number a))
                           (eq? channel (get-channel a))
                           (eq? 'cc (get-type a))))
                    (atomic-box-ref callback-list))))


(define (handle-cc-change! channel cc-number value)
  (ensure-cc-array channel)
  (let* ((cc-array (assq-ref (atomic-box-ref cc-arrays) channel))
         (old-value (vector-ref cc-array cc-number)))
    (vector-set! cc-array cc-number value)
    (check-cc-callbacks channel cc-number old-value value)))


(define* (get-cc-value cc-number
                       #:key (channel #f)
                       (unknown-val 0))
  (let ((cc-arrays (atomic-box-ref cc-arrays)))
    (let ((ccs (assq-ref cc-arrays
                         (if channel channel default-channel))))
      (if ccs
          (let ((val (vector-ref ccs cc-number)))
            (if val val unknown-val))
          unknown-val))))


(define (check-note-callbacks channel note-number)
  (for-each (lambda (a) ((get-callback-func a)))
            (filter (lambda (a)
                      (and (eq? note-number (get-note-or-cc-number a))
                           (eq? channel (get-channel a))
                           (eq? 'note (get-type a))))
                    (atomic-box-ref callback-list))))


(define (scale-127-100 n)
  (/ (* n 100) 127))


(define default-channel 0)

(define* (start-midi-control device-name
                             #:key (channel #f))

  (when channel
    (set! default-channel channel))

  (let ((midi-port (open-file device-name "r+0b")))

    ;; Read thread
    (begin-thread
     (let again ()

       (let* ((status-byte (get-u8 midi-port))
              (channel (bit-extract status-byte 0 4))
              (command (bit-extract status-byte 4 8)))

         (case command

           ;; Note on
           ((9) (let* ((note (get-u8 midi-port))
                       (vel (get-u8 midi-port)))
                  (check-note-callbacks channel note)))

           ;; Control value
           ((11) (let* ((cc-number (get-u8 midi-port))
                        (value (get-u8 midi-port)))
                   (handle-cc-change! channel
                                      cc-number
                                      value))))

         (yield)
         (again))))

    ;; Write thread
    (begin-thread
     (let again ()
       (let ((bytes-to-send (atomic-box-swap! send-queue '())))
         (for-each (lambda (a)
                     (put-u8 midi-port a))
                   bytes-to-send)
         (usleep 1000)
         (again))))))