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
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
|
//
// dolmetschctl
//
//
// Copyright (C) 2019 Christian Pointner <equinox@spreadspace.org>
//
// This file is part of dolmetschctl.
//
// dolmetschctl is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// dolmetschctl is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with dolmetschctl. If not, see <http://www.gnu.org/licenses/>.
//
package controller
import (
"container/list"
"errors"
"fmt"
// "log"
"strings"
"sync"
"github.com/scgolang/midi"
)
const (
BUTTON_ON = byte(0x90)
BUTTON_OFF = byte(0x80)
NOTE_OFFSET_BUTTON = byte(0x00)
NUM_BUTTONS = 4
LED_CC = byte(0xB0)
NOTE_OFFSET_LED = byte(0x00)
NUM_LEDS = 4
LED_OFF = byte(0x00)
LED_ON = byte(0x01)
LED_TOGGLE = byte(0x02)
LED_BLINK_MIN = byte(0x03)
LED_BLINK_MAX = byte(0x7f)
)
type EventType int
const (
ButtonPressed EventType = iota
ButtonReleased
)
func (e EventType) String() string {
switch e {
case ButtonPressed:
return "button pressed"
case ButtonReleased:
return "button released"
default:
return "unknown"
}
}
type Event struct {
Button byte
Type EventType
}
type subscriber struct {
publish chan<- Event
unsubscribe <-chan struct{}
}
type Controller struct {
Dev *midi.Device
subscribersLock sync.Mutex
subscribers list.List
}
func openDevice(devices []*midi.Device, prefix string) (d *midi.Device, err error) {
for _, device := range devices {
if strings.HasPrefix(device.Name, prefix) {
d = device
}
}
if d == nil {
return nil, errors.New("could not find device with prefix: " + prefix)
}
return d, d.Open()
}
func NewController(c Config) (*Controller, error) {
devices, err := midi.Devices()
if err != nil {
return nil, err
}
ctrl := &Controller{}
if ctrl.Dev, err = openDevice(devices, c.Dev); err != nil {
return nil, err
}
ctrl.Dev.QueueSize = 100
return ctrl, nil
}
func (c *Controller) publishEvent(ev Event) {
c.subscribersLock.Lock()
defer c.subscribersLock.Unlock()
var next *list.Element
for entry := c.subscribers.Front(); entry != nil; entry = next {
next = entry.Next()
sub, ok := (entry.Value).(subscriber)
if !ok {
panic(fmt.Sprintf("controller: subscriber list element value has wrong type: %T", entry.Value))
}
select {
case <-sub.unsubscribe:
// log.Printf("controller: removing subscriber '%v', because it has unsubscribed", sub.publish)
close(sub.publish)
c.subscribers.Remove(entry)
default:
select {
case sub.publish <- ev:
default:
// log.Printf("controller: removing subscriber '%v', because it is not responding", sub.publish)
close(sub.publish)
c.subscribers.Remove(entry)
}
}
}
}
func (c *Controller) handleMidiPacket(p midi.Packet) {
ev := Event{Button: p.Data[1]}
switch p.Data[0] {
case BUTTON_ON:
ev.Type = ButtonPressed
case BUTTON_OFF:
ev.Type = ButtonReleased
default:
// ignore all other events
return
}
c.publishEvent(ev)
}
func (c *Controller) Init() error {
ch, err := c.Dev.Packets()
if err != nil {
return err
}
go func() {
for {
ps := <-ch
for _, p := range ps {
if p.Err != nil {
c.Shutdown()
}
c.handleMidiPacket(p)
}
}
}()
return nil
}
func (c *Controller) Shutdown() error {
if c.Dev != nil {
c.Dev.Close()
c.Dev = nil
}
c.subscribersLock.Lock()
defer c.subscribersLock.Unlock()
for entry := c.subscribers.Front(); entry != nil; entry = entry.Next() {
sub, ok := (entry.Value).(subscriber)
if !ok {
panic(fmt.Sprintf("controller: subscriber list element value has wrong type: %T", entry.Value))
}
close(sub.publish)
}
c.subscribers.Init()
return nil
}
func (c *Controller) setLed(num byte, value byte) error {
if num >= NUM_LEDS {
return fmt.Errorf("this controller has only %d leds.", NUM_LEDS)
}
n, err := c.Dev.Write([]byte{LED_CC, NOTE_OFFSET_LED + num, value})
if err != nil {
// reopen device?
return err
}
if n != 3 {
return errors.New("sending LED command failed.")
}
return nil
}
func (c *Controller) LedOff(num byte) error {
return c.setLed(num, LED_OFF)
}
func (c *Controller) LedOn(num byte) error {
return c.setLed(num, LED_ON)
}
func (c *Controller) LedToggle(num byte) error {
return c.setLed(num, LED_TOGGLE)
}
func (c *Controller) LedBlink(num, wait byte) error {
if (wait + LED_BLINK_MIN) > LED_BLINK_MAX {
return fmt.Errorf("blink wait must be between 0 and %d.", LED_BLINK_MAX-LED_BLINK_MIN)
}
return c.setLed(num, wait+LED_BLINK_MIN)
}
func (c *Controller) Subscribe(out chan<- Event) chan<- struct{} {
c.subscribersLock.Lock()
defer c.subscribersLock.Unlock()
// log.Printf("controller: subscribing '%v' to events", out)
unsubscribe := make(chan struct{})
c.subscribers.PushBack(subscriber{publish: out, unsubscribe: unsubscribe})
return unsubscribe
}
|
