feat(GamePad): Implemented mappings

controller.go

@@ -1,25 +1,31 @@
 package main
 
 import (
-	"log"
 	"gitlab.com/gomidi/midi/v2"
+	"github.com/bendahl/uinput"
 )
 
 type Controller struct {
 	midiInput *MidiInput
 	mappings []Mapping
 	abortChan chan interface{}
+	virtGamepad uinput.Gamepad
 }
 
-func NewController(portName string) (*Controller, error) {
+func NewController(portName string, vendorID, productID uint16) (*Controller, error) {
 	midiInput, err := NewMidiInput(portName)
 	if err != nil {
 		return nil, err
 	}
 
+	virtGamepad, err := uinput.CreateGamepad("/dev/uinput", []byte(portName), vendorID, productID)
+	if err != nil {
+		return nil, err
+	}
+
 	abortChan := make(chan interface{})
 
-	controller := &Controller{midiInput, nil, abortChan}
+	controller := &Controller{midiInput, nil, abortChan, virtGamepad}
 
 	go func() {
 		for {
@@ -42,12 +48,11 @@ func (c *Controller) AddMapping(mapping Mapping) {
 func (c Controller) Stop() {
 	c.midiInput.Stop()
 	c.abortChan <- struct{}{}
+	c.virtGamepad.Close()
 }
 
 func (c Controller) update(msg midi.Message) {
 	for _, mapping := range c.mappings {
-		if mapping.Is(msg) {
-			log.Println("Mapping triggered!\n")
-		}
+		mapping.TriggerIfMatch(msg, c.virtGamepad)
 	}
 }

go.mod

@@ -2,4 +2,7 @@ module datalore/midi-hid
 
 go 1.24.5
 
-require gitlab.com/gomidi/midi/v2 v2.3.16
+require (
+	github.com/bendahl/uinput v1.7.0
+	gitlab.com/gomidi/midi/v2 v2.3.16
+)

go.sum

@@ -1,2 +1,4 @@
+github.com/bendahl/uinput v1.7.0 h1:nA4fm8Wu8UYNOPykIZm66nkWEyvxzfmJ8YC02PM40jg=
+github.com/bendahl/uinput v1.7.0/go.mod h1:Np7w3DINc9wB83p12fTAM3DPPhFnAKP0WTXRqCQJ6Z8=
 gitlab.com/gomidi/midi/v2 v2.3.16 h1:yufWSENyjnJ4LFQa9BerzUm4E4aLfTyzw5nmnCteO0c=
 gitlab.com/gomidi/midi/v2 v2.3.16/go.mod h1:jDpP4O4skYi+7iVwt6Zyp18bd2M4hkjtMuw2cmgKgfw=

main.go

@@ -5,6 +5,7 @@ import (
 	"time"
 
 	"gitlab.com/gomidi/midi/v2"
+	"github.com/bendahl/uinput"
 )
 
 func must[T any](obj T, err error) T {
@@ -19,12 +20,11 @@ func main() {
 	defer midi.CloseDriver()
 
 	log.Println("Starting...")
-	controller := must(NewController("DJControl Inpulse 500 MIDI 1"))
-	controller.AddMapping(ButtonMapping{1, 7}) // play left
-	controller.AddMapping(ControlMapping{1, 0}) // volume left
+	controller := must(NewController("DJControl Inpulse 500 MIDI 1", 0x45e, 0x285)) // mimics xbox 360 controller
+	defer controller.Stop()
+
+	controller.AddMapping(ButtonMapping{"Play left", 1, 7, uinput.ButtonSouth})
+	controller.AddMapping(ControlMapping{"Volume left", 1, 0, LeftY, false})
 
 	time.Sleep(time.Second * 20)
-	log.Println("Stopping...")
-	controller.Stop()
-	log.Println("Stopped.")
 }

mapping.go

@@ -1,16 +1,22 @@
 package main
 
 import (
+	"fmt"
+
 	"gitlab.com/gomidi/midi/v2"
+	"github.com/bendahl/uinput"
 )
 
 type Mapping interface {
 	Is(midi.Message) bool
+	TriggerIfMatch(midi.Message, uinput.Gamepad) error
 }
 
 type ButtonMapping struct {
+	comment string
 	midiChannel uint8
 	midiKey uint8
+	gamepadKey int
 }
 
 func (m ButtonMapping) Is(msg midi.Message) bool {
@@ -24,9 +30,36 @@ func (m ButtonMapping) Is(msg midi.Message) bool {
 	}
 }
 
+func (m ButtonMapping) TriggerIfMatch(msg midi.Message, virtGamepad uinput.Gamepad) error {
+	if m.Is(msg) {
+		switch msg.Type() {
+		case midi.NoteOnMsg:
+			return virtGamepad.ButtonDown(m.gamepadKey)
+		case midi.NoteOffMsg:
+			return virtGamepad.ButtonUp(m.gamepadKey)
+		default:
+			return fmt.Errorf("Invalid message type triggered ButtonMapping")
+		}
+	}
+
+	return nil
+}
+
+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 {
@@ -38,3 +71,34 @@ func (m ControlMapping) Is(msg midi.Message) bool {
 		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
+		}
+
+		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
+}