From 3c7bcf3035f11b8e4299d8254154ec5ddd86693e Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Tue, 2 Jan 2024 22:13:57 +0900
Subject: [PATCH] internal/graphicsdriver/metal: bug fix: use 3 drawables for
 fullscreen

Closes #2880
---
 internal/graphicsdriver/metal/view_darwin.go | 24 +++++++++++-----
 internal/graphicsdriver/metal/view_ios.go    |  8 ++++++
 internal/graphicsdriver/metal/view_macos.go  | 29 ++++++++++++++------
 3 files changed, 46 insertions(+), 15 deletions(-)

diff --git a/internal/graphicsdriver/metal/view_darwin.go b/internal/graphicsdriver/metal/view_darwin.go
index 910f97168..ecb0d180c 100644
--- a/internal/graphicsdriver/metal/view_darwin.go
+++ b/internal/graphicsdriver/metal/view_darwin.go
@@ -22,16 +22,16 @@ import (
 )
 
 type view struct {
-	window uintptr
-	uiview uintptr
-
-	windowChanged bool
 	vsyncDisabled bool
 
 	device mtl.Device
 	ml     ca.MetalLayer
 
+	maximumDrawableCount int
+
 	once sync.Once
+
+	viewPlatform
 }
 
 func (v *view) setDrawableSize(width, height int) {
@@ -52,14 +52,24 @@ func (v *view) setDisplaySyncEnabled(enabled bool) {
 func (v *view) forceSetDisplaySyncEnabled(enabled bool) {
 	v.ml.SetDisplaySyncEnabled(enabled)
 	v.vsyncDisabled = !enabled
+	v.updateMaximumDrawableCount()
+}
 
-	if v.vsyncDisabled {
+func (v *view) updateMaximumDrawableCount() {
+	var count int
+	if v.vsyncDisabled || v.isFullscreen() {
 		// Apparently 2 makes FPS half. Use 3.
-		v.ml.SetMaximumDrawableCount(3)
+		count = 3
 	} else {
 		// Use 2 in a usual case not to cause rendering delays (#2822).
-		v.ml.SetMaximumDrawableCount(2)
+		count = 2
 	}
+
+	if v.maximumDrawableCount == count {
+		return
+	}
+	v.ml.SetMaximumDrawableCount(count)
+	v.maximumDrawableCount = count
 }
 
 func (v *view) colorPixelFormat() mtl.PixelFormat {
diff --git a/internal/graphicsdriver/metal/view_ios.go b/internal/graphicsdriver/metal/view_ios.go
index dff20eb87..ca821e909 100644
--- a/internal/graphicsdriver/metal/view_ios.go
+++ b/internal/graphicsdriver/metal/view_ios.go
@@ -42,6 +42,10 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal/mtl"
 )
 
+type viewPlatform struct {
+	uiview uintptr
+}
+
 func (v *view) setWindow(window uintptr) {
 	panic("metal: setWindow is not available on iOS")
 }
@@ -60,6 +64,10 @@ func (v *view) update() {
 	C.setFrame(v.ml.Layer(), unsafe.Pointer(v.uiview))
 }
 
+func (v *view) isFullscreen() bool {
+	return false
+}
+
 const (
 	storageMode         = mtl.StorageModeShared
 	resourceStorageMode = mtl.ResourceStorageModeShared
diff --git a/internal/graphicsdriver/metal/view_macos.go b/internal/graphicsdriver/metal/view_macos.go
index cb8fa41fc..ea5b44ed0 100644
--- a/internal/graphicsdriver/metal/view_macos.go
+++ b/internal/graphicsdriver/metal/view_macos.go
@@ -23,9 +23,15 @@ import (
 	"github.com/hajimehoshi/ebiten/v2/internal/graphicsdriver/metal/mtl"
 )
 
+type viewPlatform struct {
+	window        cocoa.NSWindow
+	windowChanged bool
+	fullscreen    bool
+}
+
 func (v *view) setWindow(window uintptr) {
 	// NSView can be updated e.g., fullscreen-state is switched.
-	v.window = window
+	v.window = cocoa.NSWindow{ID: objc.ID(window)}
 	v.windowChanged = true
 }
 
@@ -34,15 +40,22 @@ func (v *view) setUIView(uiview uintptr) {
 }
 
 func (v *view) update() {
-	if !v.windowChanged {
-		return
+	if v.windowChanged {
+		// TODO: Should this be called on the main thread?
+		v.window.ContentView().SetLayer(uintptr(v.ml.Layer()))
+		v.window.ContentView().SetWantsLayer(true)
+		v.windowChanged = false
 	}
 
-	// TODO: Should this be called on the main thread?
-	cocoaWindow := cocoa.NSWindow{ID: objc.ID(v.window)}
-	cocoaWindow.ContentView().SetLayer(uintptr(v.ml.Layer()))
-	cocoaWindow.ContentView().SetWantsLayer(true)
-	v.windowChanged = false
+	fullscreen := v.window.StyleMask()&cocoa.NSWindowStyleMaskFullScreen != 0
+	if v.fullscreen != fullscreen {
+		v.fullscreen = fullscreen
+		v.updateMaximumDrawableCount()
+	}
+}
+
+func (v *view) isFullscreen() bool {
+	return v.fullscreen
 }
 
 const (