From 1fe6d9fc06156257d5210cfa71ecb839fb190722 Mon Sep 17 00:00:00 2001
From: Ahmad Fatoum <ahmad@a3f.at>
Date: Sun, 7 Oct 2018 00:47:57 +0200
Subject: [PATCH] core: workaround window not being rendered till moved on
 macOS Mojave

Apple ought to fix their OpenGL implementation, but with OpenGL now
deprecated this might not happen.

This has been reported upstream in GLFW in glfw/glfw#1334.
The workaround comes from kovidgoyal/kitty@b82e74f99

This also fixes the HiDPI (Retina) scaling issues reported in #497,
so the workaround is enabled anywhere __APPLE__ is defined.
---
 src/core.c | 29 +++++++++++++++++++++++------
 1 file changed, 23 insertions(+), 6 deletions(-)

diff --git a/src/core.c b/src/core.c
index 203da4d9b..558cc854e 100644
--- a/src/core.c
+++ b/src/core.c
@@ -134,12 +134,6 @@
     #define CHDIR chdir
 #endif
 
-#if defined(__linux__) || defined(PLATFORM_WEB)
-    #include <sys/time.h>           // Required for: timespec, nanosleep(), select() - POSIX
-#elif defined(__APPLE__)
-    #include <unistd.h>             // Required for: usleep()
-#endif
-
 #if defined(PLATFORM_DESKTOP) || defined(PLATFORM_WEB)
     #if defined(PLATFORM_WEB)
         #define GLFW_INCLUDE_ES2
@@ -155,6 +149,15 @@
     #endif
 #endif
 
+#if defined(__linux__) || defined(PLATFORM_WEB)
+    #include <sys/time.h>           // Required for: timespec, nanosleep(), select() - POSIX
+#elif defined(__APPLE__)
+    #include <unistd.h>             // Required for: usleep()
+    #include <objc/message.h>       // Required for: objc_msgsend(), sel_registerName()
+    #define GLFW_EXPOSE_NATIVE_NSGL
+    #include <GLFW/glfw3native.h>   // Required for: glfwGetNSGLContext()
+#endif
+
 #if defined(PLATFORM_ANDROID)
     //#include <android/sensor.h>           // Android sensors functions (accelerometer, gyroscope, light...)
     #include <android/window.h>             // Defines AWINDOW_FLAG_FULLSCREEN and others
@@ -233,6 +236,11 @@ static bool windowReady = false;                // Check if window has been init
 static bool windowMinimized = false;            // Check if window has been minimized
 static const char *windowTitle = NULL;          // Window text title...
 
+#if defined(__APPLE__)
+static int windowNeedsUpdating = 2;             // Times the Cocoa window needs to be updated initially
+#endif
+
+
 #if defined(PLATFORM_ANDROID)
 static struct android_app *androidApp;          // Android activity
 static struct android_poll_source *source;      // Android events polling source
@@ -2870,6 +2878,15 @@ static void SwapBuffers(void)
 {
 #if defined(PLATFORM_DESKTOP) || defined(PLATFORM_WEB)
     glfwSwapBuffers(window);
+#if __APPLE__
+    // workaround for missing/erroneous initial rendering on macOS
+    if (windowNeedsUpdating) {
+        // Desugared version of Objective C: [glfwGetNSGLContext(window) update]
+        ((id (*)(id, SEL))objc_msgSend)(glfwGetNSGLContext(window),
+                                        sel_registerName("update"));
+        windowNeedsUpdating--;
+    }
+#endif
 #endif
 
 #if defined(PLATFORM_ANDROID) || defined(PLATFORM_RPI) || defined(PLATFORM_UWP)