ebiten: Introduce type TouchID

Fixes #604

examples/2048/2048/input.go

@@ -84,7 +84,7 @@ type Input struct {
 	mouseDir      Dir
 
 	touchState    touchState
-	touchID       int
+	touchID       ebiten.TouchID
 	touchInitPosX int
 	touchInitPosY int
 	touchLastPosX int

examples/drag/main.go

@@ -106,7 +106,7 @@ func (m *MouseStrokeSource) IsJustReleased() bool {
 
 // TouchStrokeSource is a StrokeSource implementation of touch.
 type TouchStrokeSource struct {
-	ID int
+	ID ebiten.TouchID
 }
 
 func (t *TouchStrokeSource) Position() (int, int) {

input.go

@@ -182,6 +182,9 @@ func IsGamepadButtonPressed(id GamepadID, button GamepadButton) bool {
 	return uiDriver().Input().IsGamepadButtonPressed(id, driver.GamepadButton(button))
 }
 
+// TouchID represents a touch's identifier.
+type TouchID = driver.TouchID
+
 // TouchIDs returns the current touch states.
 //
 // If you want to know whether a touch started being pressed in the current frame,
@@ -191,7 +194,7 @@ func IsGamepadButtonPressed(id GamepadID, button GamepadButton) bool {
 // TouchIDs always returns nil on desktops.
 //
 // TouchIDs is concurrent-safe.
-func TouchIDs() []int {
+func TouchIDs() []TouchID {
 	return uiDriver().Input().TouchIDs()
 }
 
@@ -200,7 +203,7 @@ func TouchIDs() []int {
 // If the touch of the specified ID is not present, TouchPosition returns (0, 0).
 //
 // TouchPosition is cuncurrent-safe.
-func TouchPosition(id int) (int, int) {
+func TouchPosition(id TouchID) (int, int) {
 	found := false
 	for _, i := range uiDriver().Input().TouchIDs() {
 		if id == i {

inpututil/inpututil.go

@@ -36,8 +36,8 @@ type inputState struct {
 	gamepadButtonDurations     map[ebiten.GamepadID][]int
 	prevGamepadButtonDurations map[ebiten.GamepadID][]int
 
-	touchDurations     map[int]int
+	touchDurations     map[ebiten.TouchID]int
-	prevTouchDurations map[int]int
+	prevTouchDurations map[ebiten.TouchID]int
 
 	m sync.RWMutex
 }
@@ -55,8 +55,8 @@ var theInputState = &inputState{
 	gamepadButtonDurations:     map[ebiten.GamepadID][]int{},
 	prevGamepadButtonDurations: map[ebiten.GamepadID][]int{},
 
-	touchDurations:     map[int]int{},
+	touchDurations:     map[ebiten.TouchID]int{},
-	prevTouchDurations: map[int]int{},
+	prevTouchDurations: map[ebiten.TouchID]int{},
 }
 
 func init() {
@@ -134,10 +134,10 @@ func (i *inputState) update() {
 	}
 
 	// Touches
-	ids := map[int]struct{}{}
+	ids := map[ebiten.TouchID]struct{}{}
 
 	// Copy the touch durations.
-	i.prevTouchDurations = map[int]int{}
+	i.prevTouchDurations = map[ebiten.TouchID]int{}
 	for id := range i.touchDurations {
 		i.prevTouchDurations[id] = i.touchDurations[id]
 	}
@@ -146,7 +146,7 @@ func (i *inputState) update() {
 		ids[id] = struct{}{}
 		i.touchDurations[id]++
 	}
-	touchIDsToDelete := []int{}
+	touchIDsToDelete := []ebiten.TouchID{}
 	for id := range i.touchDurations {
 		if _, ok := ids[id]; !ok {
 			touchIDsToDelete = append(touchIDsToDelete, id)
@@ -292,8 +292,8 @@ func GamepadButtonPressDuration(id ebiten.GamepadID, button ebiten.GamepadButton
 // JustPressedTouchIDs might return nil when there is not touch.
 //
 // JustPressedTouchIDs is concurrent safe.
-func JustPressedTouchIDs() []int {
+func JustPressedTouchIDs() []ebiten.TouchID {
-	var ids []int
+	var ids []ebiten.TouchID
 	theInputState.m.RLock()
 	for id, s := range theInputState.touchDurations {
 		if s == 1 {
@@ -301,7 +301,9 @@ func JustPressedTouchIDs() []int {
 		}
 	}
 	theInputState.m.RUnlock()
-	sort.Ints(ids)
+	sort.Slice(ids, func(a, b int) bool {
+		return ids[a] < ids[b]
+	})
 	return ids
 }
 
@@ -309,7 +311,7 @@ func JustPressedTouchIDs() []int {
 // whether the given touch is released just in the current frame.
 //
 // IsTouchJustReleased is concurrent safe.
-func IsTouchJustReleased(id int) bool {
+func IsTouchJustReleased(id ebiten.TouchID) bool {
 	theInputState.m.RLock()
 	r := theInputState.touchDurations[id] == 0 && theInputState.prevTouchDurations[id] > 0
 	theInputState.m.RUnlock()
@@ -319,7 +321,7 @@ func IsTouchJustReleased(id int) bool {
 // TouchPressDuration returns how long the touch remains in frames.
 //
 // TouchPressDuration is concurrent safe.
-func TouchPressDuration(id int) int {
+func TouchPressDuration(id ebiten.TouchID) int {
 	theInputState.m.RLock()
 	s := theInputState.touchDurations[id]
 	theInputState.m.RUnlock()

internal/driver/input.go

@@ -16,6 +16,8 @@ package driver
 
 type GamepadID int
 
+type TouchID int
+
 type Input interface {
 	CursorPosition() (x, y int)
 	GamepadSDLID(id GamepadID) string
@@ -28,7 +30,7 @@ type Input interface {
 	IsKeyPressed(key Key) bool
 	IsMouseButtonPressed(button MouseButton) bool
 	RuneBuffer() []rune
-	TouchIDs() []int
+	TouchIDs() []TouchID
-	TouchPosition(id int) (x, y int)
+	TouchPosition(id TouchID) (x, y int)
 	Wheel() (xoff, yoff float64)
 }

internal/uidriver/glfw/input.go

@@ -45,7 +45,7 @@ type Input struct {
 	cursorX            int
 	cursorY            int
 	gamepads           [16]gamePad
-	touches            map[int]pos // TODO: Implement this (#417)
+	touches            map[driver.TouchID]pos // TODO: Implement this (#417)
 	runeBuffer         []rune
 	ui                 *UserInterface
 }
@@ -173,11 +173,11 @@ func (i *Input) IsGamepadButtonPressed(id driver.GamepadID, button driver.Gamepa
 	return r
 }
 
-func (i *Input) TouchIDs() []int {
+func (i *Input) TouchIDs() []driver.TouchID {
 	if !i.ui.isRunning() {
 		return nil
 	}
-	var ids []int
+	var ids []driver.TouchID
 	_ = i.ui.t.Call(func() error {
 		if len(i.touches) == 0 {
 			return nil
@@ -190,7 +190,7 @@ func (i *Input) TouchIDs() []int {
 	return ids
 }
 
-func (i *Input) TouchPosition(id int) (x, y int) {
+func (i *Input) TouchPosition(id driver.TouchID) (x, y int) {
 	if !i.ui.isRunning() {
 		return 0, 0
 	}

internal/uidriver/js/input_js.go

@@ -46,7 +46,7 @@ type Input struct {
 	wheelX             float64
 	wheelY             float64
 	gamepads           [16]gamePad
-	touches            map[int]pos
+	touches            map[driver.TouchID]pos
 	runeBuffer         []rune
 	ui                 *UserInterface
 }
@@ -118,19 +118,19 @@ func (i *Input) IsGamepadButtonPressed(id driver.GamepadID, button driver.Gamepa
 	return i.gamepads[id].buttonPressed[button]
 }
 
-func (i *Input) TouchIDs() []int {
+func (i *Input) TouchIDs() []driver.TouchID {
 	if len(i.touches) == 0 {
 		return nil
 	}
 
-	var ids []int
+	var ids []driver.TouchID
 	for id := range i.touches {
 		ids = append(ids, id)
 	}
 	return ids
 }
 
-func (i *Input) TouchPosition(id int) (x, y int) {
+func (i *Input) TouchPosition(id driver.TouchID) (x, y int) {
 	for tid, pos := range i.touches {
 		if id == tid {
 			x, y := i.ui.context.AdjustPosition(float64(pos.X), float64(pos.Y))
@@ -346,10 +346,10 @@ func (i *Input) setMouseCursorFromEvent(e js.Value) {
 
 func (i *Input) updateTouches(e js.Value) {
 	j := e.Get("targetTouches")
-	ts := map[int]pos{}
+	ts := map[driver.TouchID]pos{}
 	for i := 0; i < j.Length(); i++ {
 		jj := j.Call("item", i)
-		id := jj.Get("identifier").Int()
+		id := driver.TouchID(jj.Get("identifier").Int())
 		ts[id] = pos{
 			X: jj.Get("clientX").Int(),
 			Y: jj.Get("clientY").Int(),

internal/uidriver/mobile/input.go

@@ -30,7 +30,7 @@ type Input struct {
 	cursorY  int
 	keys     map[driver.Key]struct{}
 	runes    []rune
-	touches  map[int]pos
+	touches  map[driver.TouchID]pos
 	gamepads []Gamepad
 	ui       *UserInterface
 }
@@ -136,7 +136,7 @@ func (i *Input) IsGamepadButtonPressed(id driver.GamepadID, button driver.Gamepa
 	return false
 }
 
-func (i *Input) TouchIDs() []int {
+func (i *Input) TouchIDs() []driver.TouchID {
 	i.ui.m.RLock()
 	defer i.ui.m.RUnlock()
 
@@ -144,14 +144,14 @@ func (i *Input) TouchIDs() []int {
 		return nil
 	}
 
-	var ids []int
+	var ids []driver.TouchID
 	for id := range i.touches {
 		ids = append(ids, id)
 	}
 	return ids
 }
 
-func (i *Input) TouchPosition(id int) (x, y int) {
+func (i *Input) TouchPosition(id driver.TouchID) (x, y int) {
 	i.ui.m.RLock()
 	defer i.ui.m.RUnlock()
 
@@ -198,7 +198,7 @@ func (i *Input) update(keys map[driver.Key]struct{}, runes []rune, touches []*To
 	i.runes = make([]rune, len(runes))
 	copy(i.runes, runes)
 
-	i.touches = map[int]pos{}
+	i.touches = map[driver.TouchID]pos{}
 	for _, t := range touches {
 		i.touches[t.ID] = pos{
 			X: t.X,

internal/uidriver/mobile/ui.go

@@ -215,7 +215,7 @@ func (u *UserInterface) appMain(a app.App) {
 				x, y := float64(e.X)/s, float64(e.Y)/s
 				// TODO: Is it ok to cast from int64 to int here?
 				touches[e.Sequence] = &Touch{
-					ID: int(e.Sequence),
+					ID: driver.TouchID(e.Sequence),
 					X:  int(x),
 					Y:  int(y),
 				}
@@ -474,7 +474,7 @@ func (u *UserInterface) Window() driver.Window {
 }
 
 type Touch struct {
-	ID int
+	ID driver.TouchID
 	X  int
 	Y  int
 }

mobile/ebitenmobileview/input.go

@@ -29,7 +29,7 @@ type position struct {
 var (
 	keys     = map[driver.Key]struct{}{}
 	runes    []rune
-	touches  = map[int]position{}
+	touches  = map[driver.TouchID]position{}
 	gamepads = map[driver.GamepadID]*mobile.Gamepad{}
 )
 

mobile/ebitenmobileview/input_android.go

@@ -201,10 +201,10 @@ func gamepadIDFromDeviceID(deviceID int) driver.GamepadID {
 func UpdateTouchesOnAndroid(action int, id int, x, y int) {
 	switch action {
 	case 0x00, 0x05, 0x02: // ACTION_DOWN, ACTION_POINTER_DOWN, ACTION_MOVE
-		touches[id] = position{x, y}
+		touches[driver.TouchID(id)] = position{x, y}
 		updateInput()
 	case 0x01, 0x06: // ACTION_UP, ACTION_POINTER_UP
-		delete(touches, id)
+		delete(touches, driver.TouchID(id))
 		updateInput()
 	}
 }

mobile/ebitenmobileview/input_ios.go

@@ -18,6 +18,8 @@ package ebitenmobileview
 
 import (
 	"fmt"
+
+	"github.com/hajimehoshi/ebiten/v2/internal/driver"
 )
 
 // #cgo CFLAGS: -x objective-c
@@ -47,12 +49,12 @@ func UpdateTouchesOnIOS(phase int, ptr int64, x, y int) {
 	switch phase {
 	case C.UITouchPhaseBegan, C.UITouchPhaseMoved, C.UITouchPhaseStationary:
 		id := getIDFromPtr(ptr)
-		touches[id] = position{x, y}
+		touches[driver.TouchID(id)] = position{x, y}
 		updateInput()
 	case C.UITouchPhaseEnded, C.UITouchPhaseCancelled:
 		id := getIDFromPtr(ptr)
 		delete(ptrToID, ptr)
-		delete(touches, id)
+		delete(touches, driver.TouchID(id))
 		updateInput()
 	default:
 		panic(fmt.Sprintf("ebitenmobileview: invalid phase: %d", phase))