internal/graphicsdriver/metal: bug fix: use 2 as a drawable count for Arm Mac

Closes #2883

internal/graphicsdriver/metal/view_darwin.go

@@ -83,8 +83,7 @@ func (v *view) initialize(device mtl.Device) error {
 	// nextDrawable took more than one second if the window has other controls like NSTextView (#1029).
 	v.ml.SetPresentsWithTransaction(false)
 
-	// Always use 3. There are some situations that the FPS becomes half, or the FPS becomes too low (#2880).
+	v.ml.SetMaximumDrawableCount(v.maximumDrawableCount())
-	v.ml.SetMaximumDrawableCount(3)
 
 	return nil
 }

internal/graphicsdriver/metal/view_ios.go

@@ -64,3 +64,8 @@ const (
 	storageMode         = mtl.StorageModeShared
 	resourceStorageMode = mtl.ResourceStorageModeShared
 )
+
+func (v *view) maximumDrawableCount() int {
+	// TODO: Is 2 available for iOS?
+	return 3
+}

internal/graphicsdriver/metal/view_macos.go

@@ -17,6 +17,8 @@
 package metal
 
 import (
+	"runtime"
+
 	"github.com/ebitengine/purego/objc"
 
 	"github.com/hajimehoshi/ebiten/v2/internal/cocoa"
@@ -49,3 +51,13 @@ const (
 	storageMode         = mtl.StorageModeManaged
 	resourceStorageMode = mtl.ResourceStorageModeManaged
 )
+
+func (v *view) maximumDrawableCount() int {
+	// Use 2 for Arm Mac (#2883).
+	if runtime.GOARCH == "arm64" {
+		return 2
+	}
+
+	// Use 3 for Intel Mac and iOS. With 2, There are some situations that the FPS becomes half, or the FPS becomes too low (#2880).
+	return 3
+}