internal/gamepad: use -overlay to provide the implementation for Nintendo Switch

Updates #2372

internal/gamepad/gamepad_nintendosdk.cpp

@@ -0,0 +1,31 @@
+// 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.
+
+//go:build nintendosdk
+
+// The actual implementaiton will be provided by -overlay.
+
+#include "gamepad_nintendosdk.h"
+
+extern "C" void ebitengine_UpdateGamepads() {}
+
+extern "C" int ebitengine_GetGamepadCount() {
+  return 0;
+}
+
+extern "C" void ebitengine_GetGamepads(struct Gamepad *gamepads) {}
+
+extern "C" void ebitengine_VibrateGamepad(int id, double durationInSeconds,
+                                          double strongMagnitude,
+                                          double weakMagnitude) {}

internal/gamepad/gamepad_nintendosdk.go

@@ -16,15 +16,25 @@
 
 package gamepad
 
+// #cgo !darwin LDFLAGS: -Wl,-unresolved-symbols=ignore-all
+// #cgo darwin LDFLAGS: -Wl,-undefined,dynamic_lookup
+//
+// #include "gamepad_nintendosdk.h"
+//
+// void ebitengine_UpdateGamepads();
+// int ebitengine_GetGamepadCount();
+// void ebitengine_GetGamepads(struct Gamepad* gamepads);
+// void ebitengine_VibrateGamepad(int id, double durationInSeconds, double strongMagnitude, double weakMagnitude);
+import "C"
+
 import (
 	"time"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/gamepaddb"
-	"github.com/hajimehoshi/ebiten/v2/internal/nintendosdk"
 )
 
 type nativeGamepadsImpl struct {
-	gamepads []nintendosdk.Gamepad
+	gamepads []C.struct_Gamepad
 	ids      map[int]struct{}
 }
 
@@ -37,8 +47,17 @@ func (*nativeGamepadsImpl) init(gamepads *gamepads) error {
 }
 
 func (g *nativeGamepadsImpl) update(gamepads *gamepads) error {
+	C.ebitengine_UpdateGamepads()
+
 	g.gamepads = g.gamepads[:0]
-	g.gamepads = nintendosdk.AppendGamepads(g.gamepads)
+	if n := int(C.ebitengine_GetGamepadCount()); n > 0 {
+		if cap(g.gamepads) < n {
+			g.gamepads = make([]C.struct_Gamepad, n)
+		} else {
+			g.gamepads = g.gamepads[:n]
+		}
+		C.ebitengine_GetGamepads(&g.gamepads[0])
+	}
 
 	for id := range g.ids {
 		delete(g.ids, id)
@@ -48,27 +67,33 @@ func (g *nativeGamepadsImpl) update(gamepads *gamepads) error {
 		if g.ids == nil {
 			g.ids = map[int]struct{}{}
 		}
-		g.ids[gp.ID] = struct{}{}
+		g.ids[int(gp.id)] = struct{}{}
 
 		gamepad := gamepads.find(func(gamepad *Gamepad) bool {
-			return gamepad.native.(*nativeGamepadImpl).id == gp.ID
+			return gamepad.native.(*nativeGamepadImpl).id == int(gp.id)
 		})
 		if gamepad == nil {
 			gamepad = gamepads.add("", "")
 			gamepad.native = &nativeGamepadImpl{
-				id:            gp.ID,
-				standard:      gp.Standard,
-				axisValues:    make([]float64, gp.AxisCount),
-				buttonPressed: make([]bool, gp.ButtonCount),
-				buttonValues:  make([]float64, gp.ButtonCount),
+				id:            int(gp.id),
+				standard:      bool(gp.standard != 0),
+				axisValues:    make([]float64, gp.axis_count),
+				buttonPressed: make([]bool, gp.button_count),
+				buttonValues:  make([]float64, gp.button_count),
 			}
 		}
 
 		gamepad.m.Lock()
 		n := gamepad.native.(*nativeGamepadImpl)
-		copy(n.axisValues, gp.AxisValues[:])
-		copy(n.buttonValues, gp.ButtonValues[:])
-		copy(n.buttonPressed, gp.ButtonPressed[:])
+		for i := range n.axisValues {
+			n.axisValues[i] = float64(gp.axis_values[i])
+		}
+		for i := range n.buttonValues {
+			n.buttonValues[i] = float64(gp.button_values[i])
+		}
+		for i := range n.buttonPressed {
+			n.buttonPressed[i] = gp.button_pressed[i] != 0
+		}
 		gamepad.m.Unlock()
 	}
 
@@ -146,5 +171,5 @@ func (*nativeGamepadImpl) hatState(hat int) int {
 }
 
 func (g *nativeGamepadImpl) vibrate(duration time.Duration, strongMagnitude float64, weakMagnitude float64) {
-	nintendosdk.VibrateGamepad(g.id, duration, strongMagnitude, weakMagnitude)
+	C.ebitengine_VibrateGamepad(C.int(g.id), C.double(float64(duration)/float64(time.Second)), C.double(strongMagnitude), C.double(weakMagnitude))
 }

internal/gamepad/gamepad_nintendosdk.h

@@ -0,0 +1,25 @@
+// 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.
+
+//go:build nintendosdk
+
+struct Gamepad {
+  int id;
+  char standard;
+  int button_count;
+  int axis_count;
+  char button_pressed[32];
+  float button_values[32];
+  float axis_values[16];
+};

internal/nintendosdk/nintendosdk.go

@@ -21,16 +21,6 @@ package nintendosdk
 //
 // #include <stdint.h>
 //
-// struct Gamepad {
-//   int id;
-//   char standard;
-//   int button_num;
-//   int axis_num;
-//   char button_pressed[32];
-//   float button_values[32];
-//   float axis_values[16];
-// };
-//
 // struct Touch {
 //   int id;
 //   int x;
@@ -44,27 +34,10 @@ package nintendosdk
 // void EbitenEndFrame();
 //
 // // Input
-// int EbitenGetGamepadNum();
-// void EbitenGetGamepads(struct Gamepad* gamepads);
 // int EbitenGetTouchNum();
 // void EbitenGetTouches(struct Touch* touches);
-// void EbitenVibrateGamepad(int id, double durationInSeconds, double strongMagnitude, double weakMagnitude);
 import "C"
 
-import (
-	"time"
-)
-
-type Gamepad struct {
-	ID            int
-	Standard      bool
-	ButtonCount   int
-	AxisCount     int
-	ButtonPressed [32]bool
-	ButtonValues  [32]float64
-	AxisValues    [16]float64
-}
-
 type Touch struct {
 	ID int
 	X  int
@@ -89,39 +62,6 @@ func EndFrame() {
 	C.EbitenEndFrame()
 }
 
-var cGamepads []C.struct_Gamepad
-
-func AppendGamepads(gamepads []Gamepad) []Gamepad {
-	n := int(C.EbitenGetGamepadNum())
-	if cap(cGamepads) < n {
-		cGamepads = append(cGamepads, make([]C.struct_Gamepad, n)...)
-	} else {
-		cGamepads = cGamepads[:n]
-	}
-	if n > 0 {
-		C.EbitenGetGamepads(&cGamepads[0])
-	}
-
-	for _, g := range cGamepads {
-		gamepad := Gamepad{
-			ID:          int(g.id),
-			Standard:    g.standard != 0,
-			ButtonCount: int(g.button_num),
-			AxisCount:   int(g.axis_num),
-		}
-		for i := 0; i < gamepad.ButtonCount; i++ {
-			gamepad.ButtonPressed[i] = g.button_pressed[i] != 0
-			gamepad.ButtonValues[i] = float64(g.button_values[i])
-		}
-		for i := 0; i < gamepad.AxisCount; i++ {
-			gamepad.AxisValues[i] = float64(g.axis_values[i])
-		}
-
-		gamepads = append(gamepads, gamepad)
-	}
-	return gamepads
-}
-
 var cTouches []C.struct_Touch
 
 func AppendTouches(touches []Touch) []Touch {
@@ -145,7 +85,3 @@ func AppendTouches(touches []Touch) []Touch {
 	}
 	return touches
 }
-
-func VibrateGamepad(id int, duration time.Duration, strongMagnitude float64, weakMagnitude float64) {
-	C.EbitenVibrateGamepad(C.int(id), C.double(float64(duration)/float64(time.Second)), C.double(strongMagnitude), C.double(weakMagnitude))
-}