Replace hasMultitap option with more general customPortDevices

The new customPortDevices option allows users to map a specific Libretro device (or multiple devices) to the input ports. For example, this allows users to map a Multitap controller with the snes9x core.

pkg/config/config.yaml

@@ -180,8 +180,12 @@ emulator:
       #   - ratio (float)
       #   - isGlAllowed (bool)
       #   - usesLibCo (bool)
-      #   - hasMultitap (bool)
+      #   - hasMultitap (bool) -- (deprecated)
       #   - coreAspectRatio (bool) -- correct the aspect ratio on the client with the info from the core.
+      #   - customPortDevices (map[int][]int)
+      #       A list of device ids to bind to the input ports.
+      #       Some cores allow binding multiple devices to a single port (DosBox), but normally
+      #       you should bind just one device to one port.
       #   - vfr (bool)
       #    (experimental)
       #       Enable variable frame rate only for cores that can't produce a constant frame rate.
@@ -226,7 +230,10 @@ emulator:
         snes:
           lib: snes9x_libretro
           roms: [ "smc", "sfc", "swc", "fig", "bs" ]
-          hasMultitap: true
+          customPortDevices:
+            # set the 2nd port to RETRO_DEVICE_JOYPAD_MULTITAP ((1<<8) | 1) as snes9x requires it
+            # in order to support up to 5 player games, see: https://nintendo.fandom.com/wiki/Super_Multitap
+            1: 257
         n64:
           lib: mupen64plus_next_libretro
           roms: [ "n64", "v64", "z64" ]

pkg/config/emulator.go

@@ -39,21 +39,21 @@ type LibretroRepoConfig struct {
 }
 
 type LibretroCoreConfig struct {
-	AltRepo         bool
-	AutoGlContext   bool // hack: keep it here to pass it down the emulator
-	CoreAspectRatio bool
-	Folder          string
-	Hacks           []string
-	HasMultitap     bool
-	Height          int
-	IsGlAllowed     bool
-	Lib             string
-	Options         map[string]string
-	Roms            []string
-	Scale           float64
-	UsesLibCo       bool
-	VFR             bool
-	Width           int
+	AltRepo           bool
+	AutoGlContext     bool // hack: keep it here to pass it down the emulator
+	CoreAspectRatio   bool
+	CustomPortDevices map[int][]int
+	Folder            string
+	Hacks             []string
+	Height            int
+	IsGlAllowed       bool
+	Lib               string
+	Options           map[string]string
+	Roms              []string
+	Scale             float64
+	UsesLibCo         bool
+	VFR               bool
+	Width             int
 }
 
 type CoreInfo struct {

pkg/worker/caged/libretro/frontend.go

@@ -43,8 +43,6 @@ type Emulator interface {
 	HasSave() bool
 	// Close will be called when the game is done
 	Close()
-	// ToggleMultitap toggles multitap controller.
-	ToggleMultitap()
 	// Input passes input to the emulator
 	Input(player int, data []byte)
 	// Scale returns set video scale factor
@@ -157,15 +155,15 @@ func NewFrontend(conf config.Emulator, log *logger.Logger) (*Frontend, error) {
 func (f *Frontend) LoadCore(emu string) {
 	conf := f.conf.GetLibretroCoreConfig(emu)
 	meta := nanoarch.Metadata{
-		AutoGlContext:   conf.AutoGlContext,
-		Hacks:           conf.Hacks,
-		HasMultitap:     conf.HasMultitap,
-		HasVFR:          conf.VFR,
-		IsGlAllowed:     conf.IsGlAllowed,
-		LibPath:         conf.Lib,
-		Options:         conf.Options,
-		UsesLibCo:       conf.UsesLibCo,
-		CoreAspectRatio: conf.CoreAspectRatio,
+		AutoGlContext:     conf.AutoGlContext,
+		Hacks:             conf.Hacks,
+		HasVFR:            conf.VFR,
+		IsGlAllowed:       conf.IsGlAllowed,
+		LibPath:           conf.Lib,
+		Options:           conf.Options,
+		UsesLibCo:         conf.UsesLibCo,
+		CoreAspectRatio:   conf.CoreAspectRatio,
+		CustomPortDevices: conf.CustomPortDevices,
 	}
 	f.mu.Lock()
 	scale := 1.0
@@ -310,7 +308,6 @@ func (f *Frontend) SetSessionId(name string)      { f.storage.SetMainSaveName(na
 func (f *Frontend) SetDataCb(cb func([]byte))     { f.onData = cb }
 func (f *Frontend) SetVideoCb(ff func(app.Video)) { f.onVideo = ff }
 func (f *Frontend) Tick()                         { f.mu.Lock(); f.nano.Run(); f.mu.Unlock() }
-func (f *Frontend) ToggleMultitap()               { f.nano.ToggleMultitap() }
 func (f *Frontend) ViewportRecalculate()          { f.mu.Lock(); f.vw, f.vh = f.ViewportCalc(); f.mu.Unlock() }
 func (f *Frontend) ViewportSize() (int, int)      { return f.vw, f.vh }
 

pkg/worker/caged/libretro/nanoarch/nanoarch.go

@@ -43,11 +43,7 @@ type Nanoarch struct {
 	Handlers
 	LastFrameTime int64
 	LibCo         bool
-	multitap      struct {
-		supported bool
-		enabled   bool
-		value     C.unsigned
-	}
+	meta          Metadata
 	options       *map[string]string
 	reserved      chan struct{} // limits concurrent use
 	Rot           uint
@@ -92,15 +88,15 @@ type FrameInfo struct {
 }
 
 type Metadata struct {
-	LibPath         string // the full path to some emulator lib
-	IsGlAllowed     bool
-	UsesLibCo       bool
-	AutoGlContext   bool
-	HasMultitap     bool
-	HasVFR          bool
-	Options         map[string]string
-	Hacks           []string
-	CoreAspectRatio bool
+	LibPath           string // the full path to some emulator lib
+	IsGlAllowed       bool
+	UsesLibCo         bool
+	AutoGlContext     bool
+	HasVFR            bool
+	Options           map[string]string
+	Hacks             []string
+	CoreAspectRatio   bool
+	CustomPortDevices map[int][]int
 }
 
 type PixFmt struct {
@@ -159,6 +155,7 @@ func (n *Nanoarch) SetVideoDebounce(t time.Duration) { n.limiter = NewLimit(t) }
 
 func (n *Nanoarch) CoreLoad(meta Metadata) {
 	var err error
+	n.meta = meta
 	n.LibCo = meta.UsesLibCo
 	n.vfr = meta.HasVFR
 	n.Aspect = meta.CoreAspectRatio
@@ -170,10 +167,6 @@ func (n *Nanoarch) CoreLoad(meta Metadata) {
 
 	n.options = &meta.Options
 
-	n.multitap.supported = meta.HasMultitap
-	n.multitap.enabled = false
-	n.multitap.value = 0
-
 	filePath := meta.LibPath
 	if ar, err := arch.Guess(); err == nil {
 		filePath = filePath + ar.LibExt
@@ -298,34 +291,24 @@ func (n *Nanoarch) LoadGame(path string) error {
 	}
 
 	// set default controller types on all ports
+	// needed for nestopia
 	for i := 0; i < MaxPort; i++ {
 		C.bridge_retro_set_controller_port_device(retroSetControllerPortDevice, C.uint(i), C.RETRO_DEVICE_JOYPAD)
 	}
 
+	// map custom devices to ports
+	for k, v := range n.meta.CustomPortDevices {
+		for _, device := range v {
+			C.bridge_retro_set_controller_port_device(retroSetControllerPortDevice, C.uint(k), C.unsigned(device))
+			n.log.Debug().Msgf("set custom port-device: %v:%v", k, device)
+		}
+	}
+
 	n.LastFrameTime = time.Now().UnixNano()
 
 	return nil
 }
 
-// ToggleMultitap toggles multitap controller for cores.
-//
-// Official SNES games only support a single multitap device
-// Most require it to be plugged in player 2 port and Snes9X requires it
-// to be "plugged" after the game is loaded.
-// Control this from the browser since player 2 will stop working in some games
-// if multitap is "plugged" in.
-func (n *Nanoarch) ToggleMultitap() {
-	if !n.multitap.supported || n.multitap.value == 0 {
-		return
-	}
-	mt := n.multitap.value
-	if n.multitap.enabled {
-		mt = C.RETRO_DEVICE_JOYPAD
-	}
-	C.bridge_retro_set_controller_port_device(retroSetControllerPortDevice, 1, mt)
-	n.multitap.enabled = !n.multitap.enabled
-}
-
 func (n *Nanoarch) Shutdown() {
 	if n.LibCo {
 		thread.Main(func() {
@@ -776,22 +759,26 @@ func coreEnvironment(cmd C.unsigned, data unsafe.Pointer) C.bool {
 		return false
 	case C.RETRO_ENVIRONMENT_SET_CONTROLLER_INFO:
 		// !to rewrite
-		if !Nan0.multitap.supported {
-			return false
-		}
-		info := (*[100]C.struct_retro_controller_info)(data)
-		var i C.unsigned
-		for i = 0; unsafe.Pointer(info[i].types) != nil; i++ {
-			var j C.unsigned
-			types := (*[100]C.struct_retro_controller_description)(unsafe.Pointer(info[i].types))
-			for j = 0; j < info[i].num_types; j++ {
-				if C.GoString(types[j].desc) == "Multitap" {
-					Nan0.multitap.value = types[j].id
-					return true
+		info := (*[64]C.struct_retro_controller_info)(data)
+		for c, controller := range info {
+			tp := unsafe.Pointer(controller.types)
+			if tp == nil {
+				break
+			}
+			cInfo := strings.Builder{}
+			cInfo.WriteString(fmt.Sprintf("Controller [%v] ", c))
+			cd := (*[32]C.struct_retro_controller_description)(tp)
+			delim := ", "
+			n := int(controller.num_types)
+			for i := 0; i < n; i++ {
+				if i == n-1 {
+					delim = ""
 				}
+				cInfo.WriteString(fmt.Sprintf("%v: %v%s", cd[i].id, C.GoString(cd[i].desc), delim))
 			}
+			Nan0.log.Debug().Msgf("%v", cInfo.String())
 		}
-		return false
+		return true
 	case C.RETRO_ENVIRONMENT_GET_CLEAR_ALL_THREAD_WAITS_CB:
 		C.bridge_clear_all_thread_waits_cb(data)
 		return true

pkg/worker/coordinatorhandlers.go

@@ -234,11 +234,11 @@ func (c *coordinator) HandleChangePlayer(rq api.ChangePlayerRequest[com.Uid], w
 }
 
 func (c *coordinator) HandleToggleMultitap(rq api.ToggleMultitapRequest[com.Uid], w *Worker) api.Out {
+	// !to remove completely
 	r := w.router.FindRoom(rq.Rid)
 	if r == nil {
 		return api.ErrPacket
 	}
-	room.WithEmulator(r.App()).ToggleMultitap()
 	return api.OkPacket
 }