diff --git a/app/darwin_amd64.go b/app/darwin_amd64.go
index dcee145..6935769 100644
--- a/app/darwin_amd64.go
+++ b/app/darwin_amd64.go
@@ -12,7 +12,7 @@ package app
 
 /*
 #cgo CFLAGS: -x objective-c
-#cgo LDFLAGS: -framework Cocoa -framework OpenGL -framework QuartzCore
+#cgo LDFLAGS: -framework Cocoa -framework OpenGL
 #import <Carbon/Carbon.h> // for HIToolbox/Events.h
 #import <Cocoa/Cocoa.h>
 #include <pthread.h>
@@ -70,45 +70,52 @@ func main(f func(App)) {
 // events in runApp, it starts loop on another goroutine. It is locked
 // to an OS thread for its OpenGL context.
 //
-// Two Cocoa threads deliver draw signals to loop. The primary source of
-// draw events is the CVDisplayLink timer, which is tied to the display
-// vsync. Secondary draw events come from [NSView drawRect:] when the
-// window is resized.
+// The loop processes GL calls until a publish event appears.
+// Then it runs any remaining GL calls and flushes the screen.
+//
+// As NSOpenGLCPSwapInterval is set to 1, the call to CGLFlushDrawable
+// blocks until the screen refresh.
 func (a *app) loop(ctx C.GLintptr) {
 	runtime.LockOSThread()
 	C.makeCurrentContext(ctx)
 
 	workAvailable := a.worker.WorkAvailable()
+
 	for {
 		select {
 		case <-workAvailable:
 			a.worker.DoWork()
-		case <-draw:
+		case <-theApp.publish:
 		loop1:
 			for {
 				select {
 				case <-workAvailable:
 					a.worker.DoWork()
-				case <-theApp.publish:
-					C.CGLFlushDrawable(C.CGLGetCurrentContext())
-					theApp.publishResult <- PublishResult{}
+				default:
 					break loop1
 				}
 			}
-			drawDone <- struct{}{}
+			C.CGLFlushDrawable(C.CGLGetCurrentContext())
+			theApp.publishResult <- PublishResult{}
+			select {
+			case drawDone <- struct{}{}:
+			default:
+			}
 		}
 	}
 }
 
-var (
-	draw     = make(chan struct{})
-	drawDone = make(chan struct{})
-)
+var drawDone = make(chan struct{})
 
+// drawgl is used by Cocoa to occasionally request screen updates.
+//
 //export drawgl
 func drawgl() {
-	draw <- struct{}{}
-	<-drawDone
+	switch theApp.lifecycleStage {
+	case lifecycle.StageFocused, lifecycle.StageVisible:
+		theApp.Send(paint.Event{})
+		<-drawDone
+	}
 }
 
 //export startloop
diff --git a/app/darwin_amd64.m b/app/darwin_amd64.m
index 49ef8e2..c7c5fcd 100644
--- a/app/darwin_amd64.m
+++ b/app/darwin_amd64.m
@@ -11,14 +11,6 @@
 #import <Cocoa/Cocoa.h>
 #import <Foundation/Foundation.h>
 #import <OpenGL/gl3.h>
-#import <QuartzCore/CVReturn.h>
-#import <QuartzCore/CVBase.h>
-
-static CVReturn displayLinkDraw(CVDisplayLinkRef displayLink, const CVTimeStamp* now, const CVTimeStamp* outputTime, CVOptionFlags flagsIn, CVOptionFlags* flagsOut, void* displayLinkContext)
-{
-	drawgl();
-	return kCVReturnSuccess;
-}
 
 void makeCurrentContext(GLintptr context) {
 	NSOpenGLContext* ctx = (NSOpenGLContext*)context;
@@ -33,10 +25,8 @@ uint64 threadID() {
 	return id;
 }
 
-
 @interface MobileGLView : NSOpenGLView<NSApplicationDelegate, NSWindowDelegate>
 {
-	CVDisplayLinkRef displayLink;
 }
 @end
 
@@ -46,13 +36,6 @@ uint64 threadID() {
 	GLint swapInt = 1;
 	[[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
 
-	CVDisplayLinkCreateWithActiveCGDisplays(&displayLink);
-	CVDisplayLinkSetOutputCallback(displayLink, &displayLinkDraw, self);
-
-	CGLContextObj cglContext = [[self openGLContext] CGLContextObj];
-	CGLPixelFormatObj cglPixelFormat = [[self pixelFormat] CGLPixelFormatObj];
-	CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(displayLink, cglContext, cglPixelFormat);
-
 	// Using attribute arrays in OpenGL 3.3 requires the use of a VBA.
 	// But VBAs don't exist in ES 2. So we bind a default one.
 	GLuint vba;
@@ -96,11 +79,8 @@ uint64 threadID() {
 }
 
 - (void)drawRect:(NSRect)theRect {
-	// Called during resize. Do an extra draw if we are visible.
-	// This gets rid of flicker when resizing.
-	if (CVDisplayLinkIsRunning(displayLink)) {
-		drawgl();
-	}
+	// Called during resize. This gets rid of flicker when resizing.
+	drawgl();
 }
 
 - (void)mouseDown:(NSEvent *)theEvent {
@@ -136,7 +116,6 @@ uint64 threadID() {
 	[[NSRunningApplication currentApplication] activateWithOptions:(NSApplicationActivateAllWindows | NSApplicationActivateIgnoringOtherApps)];
 	[self.window makeKeyAndOrderFront:self];
 	lifecycleVisible();
-	CVDisplayLinkStart(displayLink);
 }
 
 - (void)applicationWillTerminate:(NSNotification *)aNotification {
@@ -144,17 +123,14 @@ uint64 threadID() {
 }
 
 - (void)applicationDidHide:(NSNotification *)aNotification {
-	CVDisplayLinkStop(displayLink);
 	lifecycleAlive();
 }
 
 - (void)applicationWillUnhide:(NSNotification *)notification {
 	lifecycleVisible();
-	CVDisplayLinkStart(displayLink);
 }
 
 - (void)windowWillClose:(NSNotification *)notification {
-	CVDisplayLinkStop(displayLink);
 	lifecycleAlive();
 }
 @end
@@ -204,7 +180,6 @@ uint64 threadID() {
 }
 @end
 
-
 void
 runApp(void) {
 	[NSAutoreleasePool new];