NSGL: Remove problematic swap interval workaround

Fixes #1483.

(cherry picked from commit 54e8e0b092)

README.md

@@ -143,6 +143,7 @@ information on what to include when reporting a bug.
  - [Wayland] Bugfix: The `GLFW_HAND_CURSOR` shape used the wrong image (#1432)
  - [NSGL] Bugfix: `GLFW_COCOA_RETINA_FRAMEBUFFER` had no effect on newer
    macOS versions (#1442)
+ - [NSGL] Bugfix: Workaround for swap interval on 10.14 broke on 10.12 (#1483)
 
 
 ## Contact

src/cocoa_window.m

@@ -322,12 +322,6 @@ static const NSRange kEmptyRange = { NSNotFound, 0 };
     _glfwInputWindowFocus(window, GLFW_FALSE);
 }
 
-- (void)windowDidChangeScreen:(NSNotification *)notification
-{
-    if (window->context.source == GLFW_NATIVE_CONTEXT_API)
-        _glfwUpdateDisplayLinkDisplayNSGL(window);
-}
-
 @end
 
 

src/nsgl_context.h

@@ -44,10 +44,6 @@ typedef struct _GLFWcontextNSGL
 {
     id                pixelFormat;
     id                object;
-    CVDisplayLinkRef  displayLink;
-    atomic_int        swapInterval;
-    int               swapIntervalsPassed;
-    id                swapIntervalCond;
 
 } _GLFWcontextNSGL;
 
@@ -67,5 +63,4 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
                                 const _GLFWctxconfig* ctxconfig,
                                 const _GLFWfbconfig* fbconfig);
 void _glfwDestroyContextNSGL(_GLFWwindow* window);
-void _glfwUpdateDisplayLinkDisplayNSGL(_GLFWwindow* window);
 

src/nsgl_context.m

@@ -28,30 +28,6 @@
 
 #include "internal.h"
 
-// Display link callback for manual swap interval implementation
-// This is based on a similar workaround added to SDL2
-//
-static CVReturn displayLinkCallback(CVDisplayLinkRef displayLink,
-                                    const CVTimeStamp* now,
-                                    const CVTimeStamp* outputTime,
-                                    CVOptionFlags flagsIn,
-                                    CVOptionFlags* flagsOut,
-                                    void* userInfo)
-{
-    _GLFWwindow* window = (_GLFWwindow *) userInfo;
-
-    const int interval = atomic_load(&window->context.nsgl.swapInterval);
-    if (interval > 0)
-    {
-        [window->context.nsgl.swapIntervalCond lock];
-        window->context.nsgl.swapIntervalsPassed++;
-        [window->context.nsgl.swapIntervalCond signal];
-        [window->context.nsgl.swapIntervalCond unlock];
-    }
-
-    return kCVReturnSuccess;
-}
-
 static void makeContextCurrentNSGL(_GLFWwindow* window)
 {
     @autoreleasepool {
@@ -69,33 +45,21 @@ static void makeContextCurrentNSGL(_GLFWwindow* window)
 static void swapBuffersNSGL(_GLFWwindow* window)
 {
     @autoreleasepool {
-
-    const int interval = atomic_load(&window->context.nsgl.swapInterval);
-    if (interval > 0)
-    {
-        [window->context.nsgl.swapIntervalCond lock];
-        do
-        {
-            [window->context.nsgl.swapIntervalCond wait];
-        } while (window->context.nsgl.swapIntervalsPassed % interval != 0);
-        window->context.nsgl.swapIntervalsPassed = 0;
-        [window->context.nsgl.swapIntervalCond unlock];
-    }
-
-    // ARP appears to be unnecessary, but this is future-proof
     [window->context.nsgl.object flushBuffer];
-
     } // autoreleasepool
 }
 
 static void swapIntervalNSGL(int interval)
 {
     @autoreleasepool {
-    _GLFWwindow* window = _glfwPlatformGetTls(&_glfw.contextSlot);
-    atomic_store(&window->context.nsgl.swapInterval, interval);
-    [window->context.nsgl.swapIntervalCond lock];
-    window->context.nsgl.swapIntervalsPassed = 0;
-    [window->context.nsgl.swapIntervalCond unlock];
+
+    NSOpenGLContext* context = [NSOpenGLContext currentContext];
+    if (context)
+    {
+        [context setValues:&interval
+              forParameter:NSOpenGLContextParameterSwapInterval];
+    }
+
     } // autoreleasepool
 }
 
@@ -123,17 +87,6 @@ static void destroyContextNSGL(_GLFWwindow* window)
 {
     @autoreleasepool {
 
-    if (window->context.nsgl.displayLink)
-    {
-        if (CVDisplayLinkIsRunning(window->context.nsgl.displayLink))
-            CVDisplayLinkStop(window->context.nsgl.displayLink);
-
-        CVDisplayLinkRelease(window->context.nsgl.displayLink);
-    }
-
-    [window->context.nsgl.swapIntervalCond release];
-    window->context.nsgl.swapIntervalCond = nil;
-
     [window->context.nsgl.pixelFormat release];
     window->context.nsgl.pixelFormat = nil;
 
@@ -363,14 +316,8 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
 
     [window->ns.view setWantsBestResolutionOpenGLSurface:window->ns.retina];
 
-    GLint interval = 0;
-    [window->context.nsgl.object setValues:&interval
-                              forParameter:NSOpenGLContextParameterSwapInterval];
-
     [window->context.nsgl.object setView:window->ns.view];
 
-    window->context.nsgl.swapIntervalCond = [NSCondition new];
-
     window->context.makeCurrent = makeContextCurrentNSGL;
     window->context.swapBuffers = swapBuffersNSGL;
     window->context.swapInterval = swapIntervalNSGL;
@@ -378,26 +325,9 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
     window->context.getProcAddress = getProcAddressNSGL;
     window->context.destroy = destroyContextNSGL;
 
-    CVDisplayLinkCreateWithActiveCGDisplays(&window->context.nsgl.displayLink);
-    CVDisplayLinkSetOutputCallback(window->context.nsgl.displayLink,
-                                   &displayLinkCallback,
-                                   window);
-    CVDisplayLinkStart(window->context.nsgl.displayLink);
-
-    _glfwUpdateDisplayLinkDisplayNSGL(window);
     return GLFW_TRUE;
 }
 
-void _glfwUpdateDisplayLinkDisplayNSGL(_GLFWwindow* window)
-{
-    CGDirectDisplayID displayID =
-        [[[window->ns.object screen] deviceDescription][@"NSScreenNumber"] unsignedIntValue];
-    if (!displayID)
-        return;
-
-    CVDisplayLinkSetCurrentCGDisplay(window->context.nsgl.displayLink, displayID);
-}
-
 
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////