From 8d7e5cdb49a1a5247df612157ecffdd8e68923d2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Camilla=20L=C3=B6wy?= <elmindreda@glfw.org>
Date: Thu, 21 Feb 2019 00:35:53 +0100
Subject: [PATCH] NSGL: Update current display for display link

This solution of one display link per window is far from ideal but is
still better than no solution.

As a side-effect this fixes swap interval breaking being ignored for
occluded windows on earlier versions of macOS.

Fixes #680.
Fixes #1337.
Related to #1417.
Fixes #1435.
---
 src/cocoa_monitor.m  |  2 --
 src/cocoa_platform.h |  3 +++
 src/cocoa_window.m   |  6 ++++++
 src/nsgl_context.h   |  3 +--
 src/nsgl_context.m   | 18 +++++++++++++-----
 5 files changed, 23 insertions(+), 9 deletions(-)

diff --git a/src/cocoa_monitor.m b/src/cocoa_monitor.m
index acaba8c4..a5138572 100644
--- a/src/cocoa_monitor.m
+++ b/src/cocoa_monitor.m
@@ -32,8 +32,6 @@
 #include <math.h>
 
 #include <IOKit/graphics/IOGraphicsLib.h>
-#include <CoreVideo/CVBase.h>
-#include <CoreVideo/CVDisplayLink.h>
 #include <ApplicationServices/ApplicationServices.h>
 
 
diff --git a/src/cocoa_platform.h b/src/cocoa_platform.h
index 7f188492..9c28cb67 100644
--- a/src/cocoa_platform.h
+++ b/src/cocoa_platform.h
@@ -28,6 +28,9 @@
 #include <dlfcn.h>
 
 #include <Carbon/Carbon.h>
+#include <CoreVideo/CVBase.h>
+#include <CoreVideo/CVDisplayLink.h>
+
 #if defined(__OBJC__)
 #import <Cocoa/Cocoa.h>
 #else
diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index 11702778..888edc9a 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -338,6 +338,12 @@ 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
 
 
diff --git a/src/nsgl_context.h b/src/nsgl_context.h
index 9f2ebb52..27af3335 100755
--- a/src/nsgl_context.h
+++ b/src/nsgl_context.h
@@ -27,8 +27,6 @@
 #define _GLFW_PLATFORM_CONTEXT_STATE            _GLFWcontextNSGL nsgl
 #define _GLFW_PLATFORM_LIBRARY_CONTEXT_STATE    _GLFWlibraryNSGL nsgl
 
-#import <CoreVideo/CoreVideo.h>
-
 #include <stdatomic.h>
 
 
@@ -61,4 +59,5 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
                                 const _GLFWctxconfig* ctxconfig,
                                 const _GLFWfbconfig* fbconfig);
 void _glfwDestroyContextNSGL(_GLFWwindow* window);
+void _glfwUpdateDisplayLinkDisplayNSGL(_GLFWwindow* window);
 
diff --git a/src/nsgl_context.m b/src/nsgl_context.m
index 2c104187..72ed3597 100755
--- a/src/nsgl_context.m
+++ b/src/nsgl_context.m
@@ -367,6 +367,8 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
 
     [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;
@@ -378,16 +380,22 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
     CVDisplayLinkSetOutputCallback(window->context.nsgl.displayLink,
                                    &displayLinkCallback,
                                    window);
-    CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(window->context.nsgl.displayLink,
-                                                      (CGLContextObj) window->context.nsgl.object,
-                                                      (CGLPixelFormatObj) window->context.nsgl.pixelFormat);
     CVDisplayLinkStart(window->context.nsgl.displayLink);
 
-    window->context.nsgl.swapIntervalCond = [NSCondition new];
-
+    _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                       //////