internal/gamepaddb: fix button assignments on Android

Updates #2309

cmd/ebitenmobile/gobind.go

@@ -545,14 +545,8 @@ public class EbitenView extends ViewGroup implements InputManager.InputDeviceLis
             return;
         }
 
-        boolean[] keyExistences = inputDevice.hasKeys(gamepadButtons);
+        // Use the same number of SDL buttons. See internal/gamepaddb/sdl.go.
-        int nbuttons = 0;
+        int nbuttons = 15;
-        for (int i = 0; i < gamepadButtons.length; i++) {
-            if (!keyExistences[i]) {
-                break;
-            }
-            nbuttons++;
-        }
 
         int naxes = 0;
         int nhats2 = 0;

internal/gamepaddb/gamepaddb.go

@@ -581,37 +581,7 @@ func Update(mappingData []byte) error {
 }
 
 func addAndroidDefaultMappings(id string) bool {
-	// See https://github.com/libsdl-org/SDL/blob/120c76c84bbce4c1bfed4e9eb74e10678bd83120/include/SDL_gamecontroller.h#L655-L680
-	const (
-		SDLControllerButtonA             = 0
-		SDLControllerButtonB             = 1
-		SDLControllerButtonX             = 2
-		SDLControllerButtonY             = 3
-		SDLControllerButtonBack          = 4
-		SDLControllerButtonGuide         = 5
-		SDLControllerButtonStart         = 6
-		SDLControllerButtonLeftStick     = 7
-		SDLControllerButtonRightStick    = 8
-		SDLControllerButtonLeftShoulder  = 9
-		SDLControllerButtonRightShoulder = 10
-		SDLControllerButtonDpadUp        = 11
-		SDLControllerButtonDpadDown      = 12
-		SDLControllerButtonDpadLeft      = 13
-		SDLControllerButtonDpadRight     = 14
-	)
-
-	// See https://github.com/libsdl-org/SDL/blob/120c76c84bbce4c1bfed4e9eb74e10678bd83120/include/SDL_gamecontroller.h#L550-L560
-	const (
-		SDLControllerAxisLeftX        = 0
-		SDLControllerAxisLeftY        = 1
-		SDLControllerAxisRightX       = 2
-		SDLControllerAxisRightY       = 3
-		SDLControllerAxisTriggerLeft  = 4
-		SDLControllerAxisTriggerRight = 5
-	)
-
 	// See https://github.com/libsdl-org/SDL/blob/120c76c84bbce4c1bfed4e9eb74e10678bd83120/src/joystick/SDL_gamecontroller.c#L468-L568
-
 	const faceButtonMask = ((1 << SDLControllerButtonA) |
 		(1 << SDLControllerButtonB) |
 		(1 << SDLControllerButtonX) |

internal/gamepaddb/sdl.go

@@ -0,0 +1,44 @@
+// Copyright 2022 The Ebitengine Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package gamepaddb
+
+// See https://github.com/libsdl-org/SDL/blob/120c76c84bbce4c1bfed4e9eb74e10678bd83120/include/SDL_gamecontroller.h#L655-L680
+const (
+	SDLControllerButtonA             = 0
+	SDLControllerButtonB             = 1
+	SDLControllerButtonX             = 2
+	SDLControllerButtonY             = 3
+	SDLControllerButtonBack          = 4
+	SDLControllerButtonGuide         = 5
+	SDLControllerButtonStart         = 6
+	SDLControllerButtonLeftStick     = 7
+	SDLControllerButtonRightStick    = 8
+	SDLControllerButtonLeftShoulder  = 9
+	SDLControllerButtonRightShoulder = 10
+	SDLControllerButtonDpadUp        = 11
+	SDLControllerButtonDpadDown      = 12
+	SDLControllerButtonDpadLeft      = 13
+	SDLControllerButtonDpadRight     = 14
+)
+
+// See https://github.com/libsdl-org/SDL/blob/120c76c84bbce4c1bfed4e9eb74e10678bd83120/include/SDL_gamecontroller.h#L550-L560
+const (
+	SDLControllerAxisLeftX        = 0
+	SDLControllerAxisLeftY        = 1
+	SDLControllerAxisRightX       = 2
+	SDLControllerAxisRightY       = 3
+	SDLControllerAxisTriggerLeft  = 4
+	SDLControllerAxisTriggerRight = 5
+)

mobile/ebitenmobileview/input_android.go

@@ -21,6 +21,7 @@ import (
 	"unicode"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/gamepad"
+	"github.com/hajimehoshi/ebiten/v2/internal/gamepaddb"
 	"github.com/hajimehoshi/ebiten/v2/internal/ui"
 )
 
@@ -73,38 +74,18 @@ const (
 
 // TODO: Can we map these values to the standard gamepad buttons?
 
-var androidKeyToGamepadButton = map[int]gamepad.Button{
+var androidKeyToSDLButton = map[int]int{
-	keycodeButtonA:      gamepad.Button0,
+	keycodeButtonA:      gamepaddb.SDLControllerButtonA,
-	keycodeButtonB:      gamepad.Button1,
+	keycodeButtonB:      gamepaddb.SDLControllerButtonB,
-	keycodeButtonC:      gamepad.Button2,
+	keycodeButtonX:      gamepaddb.SDLControllerButtonX,
-	keycodeButtonX:      gamepad.Button3,
+	keycodeButtonY:      gamepaddb.SDLControllerButtonY,
-	keycodeButtonY:      gamepad.Button4,
+	keycodeButtonL1:     gamepaddb.SDLControllerButtonLeftShoulder,
-	keycodeButtonZ:      gamepad.Button5,
+	keycodeButtonR1:     gamepaddb.SDLControllerButtonRightShoulder,
-	keycodeButtonL1:     gamepad.Button6,
+	keycodeButtonThumbl: gamepaddb.SDLControllerButtonLeftStick,
-	keycodeButtonR1:     gamepad.Button7,
+	keycodeButtonThumbr: gamepaddb.SDLControllerButtonRightStick,
-	keycodeButtonL2:     gamepad.Button8,
+	keycodeButtonStart:  gamepaddb.SDLControllerButtonStart,
-	keycodeButtonR2:     gamepad.Button9,
+	keycodeButtonSelect: gamepaddb.SDLControllerButtonBack,
-	keycodeButtonThumbl: gamepad.Button10,
+	keycodeButtonMode:   gamepaddb.SDLControllerButtonGuide,
-	keycodeButtonThumbr: gamepad.Button11,
-	keycodeButtonStart:  gamepad.Button12,
-	keycodeButtonSelect: gamepad.Button13,
-	keycodeButtonMode:   gamepad.Button14,
-	keycodeButton1:      gamepad.Button15,
-	keycodeButton2:      gamepad.Button16,
-	keycodeButton3:      gamepad.Button17,
-	keycodeButton4:      gamepad.Button18,
-	keycodeButton5:      gamepad.Button19,
-	keycodeButton6:      gamepad.Button20,
-	keycodeButton7:      gamepad.Button21,
-	keycodeButton8:      gamepad.Button22,
-	keycodeButton9:      gamepad.Button23,
-	keycodeButton10:     gamepad.Button24,
-	keycodeButton11:     gamepad.Button25,
-	keycodeButton12:     gamepad.Button26,
-	keycodeButton13:     gamepad.Button27,
-	keycodeButton14:     gamepad.Button28,
-	keycodeButton15:     gamepad.Button29,
-	keycodeButton16:     gamepad.Button30,
 }
 
 // Axis constant definitions for joysticks only.
@@ -143,39 +124,16 @@ const (
 	axisGeneric16 = 0x0000002f
 )
 
-var androidAxisIDToAxisID = map[int]int{
+var androidAxisToSDLAxis = map[int]int{
-	axisX:         0,
+	axisX:        gamepaddb.SDLControllerAxisLeftX,
-	axisY:         1,
+	axisY:        gamepaddb.SDLControllerAxisLeftY,
-	axisZ:         2,
+	axisRx:       gamepaddb.SDLControllerAxisRightX,
-	axisRx:        3,
+	axisRy:       gamepaddb.SDLControllerAxisRightY,
-	axisRy:        4,
+	axisLtrigger: gamepaddb.SDLControllerAxisTriggerLeft,
-	axisRz:        5,
+	axisRtrigger: gamepaddb.SDLControllerAxisTriggerRight,
-	axisLtrigger:  6,
-	axisRtrigger:  7,
-	axisThrottle:  8,
-	axisRudder:    9,
-	axisWheel:     10,
-	axisGas:       11,
-	axisBrake:     12,
-	axisGeneric1:  13,
-	axisGeneric2:  14,
-	axisGeneric3:  15,
-	axisGeneric4:  16,
-	axisGeneric5:  17,
-	axisGeneric6:  18,
-	axisGeneric7:  19,
-	axisGeneric8:  20,
-	axisGeneric9:  21,
-	axisGeneric10: 22,
-	axisGeneric11: 23,
-	axisGeneric12: 24,
-	axisGeneric13: 25,
-	axisGeneric14: 26,
-	axisGeneric15: 27,
-	axisGeneric16: 28,
 }
 
-var androidAxisIDToHatID2 = map[int]int{
+var androidAxisToHatID2 = map[int]int{
 	axisHatX: 0,
 	axisHatY: 1,
 }
@@ -195,8 +153,8 @@ func OnKeyDownOnAndroid(keyCode int, unicodeChar int, source int, deviceID int)
 	switch {
 	case source&sourceGamepad == sourceGamepad:
 		// A gamepad can be detected as a keyboard. Detect the device as a gamepad first.
-		if button, ok := androidKeyToGamepadButton[keyCode]; ok {
+		if button, ok := androidKeyToSDLButton[keyCode]; ok {
-			gamepad.UpdateAndroidGamepadButton(deviceID, button, true)
+			gamepad.UpdateAndroidGamepadButton(deviceID, gamepad.Button(button), true)
 		}
 	case source&sourceJoystick == sourceJoystick:
 		// DPAD keys can come here, but they are also treated as an axis at a motion event. Ignore them.
@@ -215,8 +173,8 @@ func OnKeyUpOnAndroid(keyCode int, source int, deviceID int) {
 	switch {
 	case source&sourceGamepad == sourceGamepad:
 		// A gamepad can be detected as a keyboard. Detect the device as a gamepad first.
-		if button, ok := androidKeyToGamepadButton[keyCode]; ok {
+		if button, ok := androidKeyToSDLButton[keyCode]; ok {
-			gamepad.UpdateAndroidGamepadButton(deviceID, button, false)
+			gamepad.UpdateAndroidGamepadButton(deviceID, gamepad.Button(button), false)
 		}
 	case source&sourceJoystick == sourceJoystick:
 		// DPAD keys can come here, but they are also treated as an axis at a motion event. Ignore them.
@@ -229,12 +187,12 @@ func OnKeyUpOnAndroid(keyCode int, source int, deviceID int) {
 }
 
 func OnGamepadAxesOrHatsChanged(deviceID int, axisID int, value float32) {
-	if axis, ok := androidAxisIDToAxisID[axisID]; ok {
+	if axis, ok := androidAxisToSDLAxis[axisID]; ok {
 		gamepad.UpdateAndroidGamepadAxis(deviceID, axis, float64(value))
 		return
 	}
 
-	if hid2, ok := androidAxisIDToHatID2[axisID]; ok {
+	if hid2, ok := androidAxisToHatID2[axisID]; ok {
 		const (
 			hatUp    = 1
 			hatRight = 2