Files
midi-hid/mapping.go

119 lines
2.3 KiB
Go

package main
import (
"fmt"
"log"
"gitlab.com/gomidi/midi/v2"
"github.com/bendahl/uinput"
)
type Mapping interface {
Is(midi.Message) bool
TriggerIfMatch(midi.Message, uinput.Gamepad) error
Comment() string
}
type ButtonMapping struct {
comment string
midiChannel uint8
midiKey uint8
gamepadKey int
}
func (m ButtonMapping) Is(msg midi.Message) bool {
var channel, key uint8
switch {
case msg.GetNoteOn(&channel, &key, nil), msg.GetNoteOff(&channel, &key, nil):
return (m.midiChannel == channel && m.midiKey == key)
default:
return false
}
}
func (m ButtonMapping) TriggerIfMatch(msg midi.Message, virtGamepad uinput.Gamepad) error {
if m.Is(msg) {
switch msg.Type() {
case midi.NoteOnMsg:
log.Printf("%s: Button down\n", m.comment)
return virtGamepad.ButtonDown(m.gamepadKey)
case midi.NoteOffMsg:
log.Printf("%s: Button up\n", m.comment)
return virtGamepad.ButtonUp(m.gamepadKey)
default:
return fmt.Errorf("Invalid message type triggered ButtonMapping")
}
}
return nil
}
func (m ButtonMapping) Comment() string {
return m.comment
}
type ControllerAxis int
const (
LeftX ControllerAxis = iota
LeftY
RightX
RightY
)
type ControlMapping struct {
comment string
midiChannel uint8
midiController uint8
axis ControllerAxis
isSigned bool
}
func (m ControlMapping) Is(msg midi.Message) bool {
var channel, controller uint8
if msg.GetControlChange(&channel, &controller, nil) {
return (m.midiChannel == channel && m.midiController == controller)
} else {
return false
}
}
func (m ControlMapping) TriggerIfMatch(msg midi.Message, virtGamepad uinput.Gamepad) error {
if m.Is(msg) {
var (
valueAbsolute uint8
valueNormalised float32
)
msg.GetControlChange(nil, nil, &valueAbsolute)
// value is 0-127, normalise
valueNormalised = float32(valueAbsolute) / 127
if m.isSigned {
valueNormalised *= 2
valueNormalised -= 1
}
log.Printf("%s: value %v\n", m.comment, valueNormalised)
switch m.axis {
case LeftX:
return virtGamepad.LeftStickMoveX(valueNormalised)
case LeftY:
return virtGamepad.LeftStickMoveY(valueNormalised)
case RightX:
return virtGamepad.RightStickMoveX(valueNormalised)
case RightY:
return virtGamepad.RightStickMoveY(valueNormalised)
}
}
return nil
}
func (m ControlMapping) Comment() string {
return m.comment
}