From e423e1c663b31676b6b6fa4c2246773daeb568c2 Mon Sep 17 00:00:00 2001
From: bruvzg <7645683+bruvzg@users.noreply.github.com>
Date: Thu, 21 Nov 2019 11:01:47 +0200
Subject: [PATCH] [macOS] Remove CVDisplayLink v-sync hack.

---
 platform/osx/os_osx.h  |  3 ---
 platform/osx/os_osx.mm | 54 ++----------------------------------------
 2 files changed, 2 insertions(+), 55 deletions(-)

diff --git a/platform/osx/os_osx.h b/platform/osx/os_osx.h
index 09a871f26c46..a61b9234d12e 100644
--- a/platform/osx/os_osx.h
+++ b/platform/osx/os_osx.h
@@ -113,9 +113,6 @@ class OS_OSX : public OS_Unix {
 	NSOpenGLContext *context;
 
 	bool layered_window;
-	bool waiting_for_vsync;
-	NSCondition *vsync_condition;
-	CVDisplayLinkRef displayLink;
 
 	CursorShape cursor_shape;
 	NSCursor *cursors[CURSOR_MAX];
diff --git a/platform/osx/os_osx.mm b/platform/osx/os_osx.mm
index ba3ac9862e4f..e5166d102b64 100644
--- a/platform/osx/os_osx.mm
+++ b/platform/osx/os_osx.mm
@@ -115,21 +115,6 @@ static Vector2 get_mouse_pos(NSPoint locationInWindow, CGFloat backingScaleFacto
 	return Vector2(mouse_x, mouse_y);
 }
 
-// DisplayLinkCallback is called from our DisplayLink OS thread informing us right before
-// a screen update is required. We can use it to work around the broken vsync.
-static CVReturn DisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeStamp *now, const CVTimeStamp *outputTime, CVOptionFlags flagsIn, CVOptionFlags *flagsOut, void *displayLinkContext) {
-	OS_OSX *os = (OS_OSX *)displayLinkContext;
-
-	// Set flag so we know we can output our next frame and signal our conditional lock
-	// if we're not doing vsync this will be ignored
-	[os->vsync_condition lock];
-	os->waiting_for_vsync = false;
-	[os->vsync_condition signal];
-	[os->vsync_condition unlock];
-
-	return kCVReturnSuccess;
-}
-
 @interface GodotApplication : NSApplication
 @end
 
@@ -1581,15 +1566,6 @@ static void displays_arrangement_changed(CGDirectDisplayID display_id, CGDisplay
 
 	[context makeCurrentContext];
 
-	// setup our display link, this will inform us when a refresh is needed
-	CVDisplayLinkCreateWithActiveCGDisplays(&displayLink);
-	CVDisplayLinkSetOutputCallback(displayLink, &DisplayLinkCallback, this);
-	CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(displayLink, context.CGLContextObj, pixelFormat.CGLPixelFormatObj);
-	CVDisplayLinkStart(displayLink);
-
-	// initialise a conditional lock object
-	vsync_condition = [[NSCondition alloc] init];
-
 	set_use_vsync(p_desired.use_vsync);
 
 	[NSApp activateIgnoringOtherApps:YES];
@@ -1682,11 +1658,6 @@ static void displays_arrangement_changed(CGDirectDisplayID display_id, CGDisplay
 	midi_driver.close();
 #endif
 
-	if (displayLink) {
-		CVDisplayLinkRelease(displayLink);
-	}
-	[vsync_condition release];
-
 	CFNotificationCenterRemoveObserver(CFNotificationCenterGetDistributedCenter(), NULL, kTISNotifySelectedKeyboardInputSourceChanged, NULL);
 	CGDisplayRemoveReconfigurationCallback(displays_arrangement_changed, NULL);
 
@@ -2258,18 +2229,6 @@ virtual void log_error(const char *p_function, const char *p_file, int p_line, c
 }
 
 void OS_OSX::swap_buffers() {
-	if (is_vsync_enabled()) {
-		// Wait until our DisplayLink callback unsets our flag...
-		[vsync_condition lock];
-		while (waiting_for_vsync)
-			[vsync_condition wait];
-
-		// Make sure we wait again next frame around
-		waiting_for_vsync = true;
-
-		[vsync_condition unlock];
-	}
-
 	[context flushBuffer];
 }
 
@@ -3009,20 +2968,11 @@ static int get_screen_index(NSScreen *screen) {
 }
 
 void OS_OSX::_set_use_vsync(bool p_enable) {
-	// CGLCPSwapInterval broke in OSX 10.14 and it seems Apple is not interested in fixing
-	// it as OpenGL is now deprecated and Metal solves this differently.
-	// Following SDLs example we're working around this using DisplayLink
-	// When vsync is enabled we set a flag "waiting_for_vsync" to true.
-	// This flag is set to false when DisplayLink informs us our display is about to refresh.
-
-	/*	CGLContextObj ctx = CGLGetCurrentContext();
+	CGLContextObj ctx = CGLGetCurrentContext();
 	if (ctx) {
 		GLint swapInterval = p_enable ? 1 : 0;
 		CGLSetParameter(ctx, kCGLCPSwapInterval, &swapInterval);
-	}*/
-
-	///TODO Maybe pause/unpause display link?
-	waiting_for_vsync = p_enable;
+	}
 }
 
 OS_OSX *OS_OSX::singleton = NULL;