From fe6a2daef4507cc7a74b27ddf906198545720a6d Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Wed, 14 Oct 2020 01:55:32 +0900
Subject: [PATCH] graphicsdriver/metal: Bug fix: Had to set the vsync state
 again at resetting

Fixes #1364
---
 examples/windowsize/main.go           | 7 ++++++-
 internal/graphicsdriver/metal/view.go | 5 +++++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/examples/windowsize/main.go b/examples/windowsize/main.go
index cacba5ea3..7beb8bc99 100644
--- a/examples/windowsize/main.go
+++ b/examples/windowsize/main.go
@@ -231,7 +231,12 @@ func (g *game) Update() error {
 	} else {
 		ebiten.SetCursorMode(ebiten.CursorModeHidden)
 	}
-	ebiten.SetVsyncEnabled(vsyncEnabled)
+
+	// Set vsync enabled only when this is needed.
+	// This makes a bug around vsync initialization more explicit (#1364).
+	if vsyncEnabled != ebiten.IsVsyncEnabled() {
+		ebiten.SetVsyncEnabled(vsyncEnabled)
+	}
 	ebiten.SetMaxTPS(tps)
 	ebiten.SetWindowDecorated(decorated)
 	ebiten.SetWindowPosition(positionX, positionY)
diff --git a/internal/graphicsdriver/metal/view.go b/internal/graphicsdriver/metal/view.go
index eabc526f7..996bf2761 100644
--- a/internal/graphicsdriver/metal/view.go
+++ b/internal/graphicsdriver/metal/view.go
@@ -28,6 +28,7 @@ type view struct {
 	uiview uintptr
 
 	windowChanged bool
+	vsync         bool
 
 	device mtl.Device
 	ml     ca.MetalLayer
@@ -45,6 +46,7 @@ func (v *view) getMTLDevice() mtl.Device {
 
 func (v *view) setDisplaySyncEnabled(enabled bool) {
 	v.ml.SetDisplaySyncEnabled(enabled)
+	v.vsync = enabled
 }
 
 func (v *view) colorPixelFormat() mtl.PixelFormat {
@@ -67,6 +69,9 @@ func (v *view) reset() error {
 	// MTLPixelFormatBGRA10_XR_sRGB.
 	v.ml.SetPixelFormat(mtl.PixelFormatBGRA8UNorm)
 	v.ml.SetMaximumDrawableCount(3)
+
+	// The vsync state might be reset. Set the state again (#1364).
+	v.ml.SetDisplaySyncEnabled(v.vsync)
 	return nil
 }