From f2b86a25b37962dd9e44c7265f8a674b547d03ed Mon Sep 17 00:00:00 2001
From: Doug Binks <doug@enkisoftware.com>
Date: Tue, 14 Jul 2020 19:10:31 +0100
Subject: [PATCH] Cocoa and NSGL Implementation

---
 src/cocoa_window.m | 19 +++++++++++++++++++
 src/nsgl_context.h | 10 ++++++++++
 src/nsgl_context.m | 47 ++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)

diff --git a/src/cocoa_window.m b/src/cocoa_window.m
index e34fb876..e7d048a9 100644
--- a/src/cocoa_window.m
+++ b/src/cocoa_window.m
@@ -1885,6 +1885,25 @@ VkResult _glfwPlatformCreateWindowSurface(VkInstance instance,
 }
 
 
+_GLFWusercontext* _glfwPlatformCreateUserContext(_GLFWwindow* window)
+{
+    if (window->context.nsgl.object)
+    {
+        return _glfwCreateUserContextNSGL(window);
+    }
+    else if (window->context.egl.handle)
+    {
+        return _glfwCreateUserContextEGL(window);
+    }
+    else if (window->context.osmesa.handle)
+    {
+        return _glfwCreateUserContextOSMesa(window);
+    }
+
+    return GLFW_FALSE;
+}
+
+
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
 //////////////////////////////////////////////////////////////////////////
diff --git a/src/nsgl_context.h b/src/nsgl_context.h
index 9c31436c..598f642b 100644
--- a/src/nsgl_context.h
+++ b/src/nsgl_context.h
@@ -34,6 +34,7 @@
 
 #define _GLFW_PLATFORM_CONTEXT_STATE            _GLFWcontextNSGL nsgl
 #define _GLFW_PLATFORM_LIBRARY_CONTEXT_STATE    _GLFWlibraryNSGL nsgl
+#define _GLFW_PLATFORM_USER_CONTEXT_STATE       _GLFWusercontextNSGL nsgl
 
 #include <stdatomic.h>
 
@@ -47,6 +48,14 @@ typedef struct _GLFWcontextNSGL
 
 } _GLFWcontextNSGL;
 
+// NSGL-specific per user context data
+//
+typedef struct _GLFWusercontextNSGL
+{
+    id                object;
+
+} _GLFWusercontextNSGL;
+
 // NSGL-specific global data
 //
 typedef struct _GLFWlibraryNSGL
@@ -63,4 +72,5 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
                                 const _GLFWctxconfig* ctxconfig,
                                 const _GLFWfbconfig* fbconfig);
 void _glfwDestroyContextNSGL(_GLFWwindow* window);
+_GLFWusercontext* _glfwCreateUserContextNSGL(_GLFWwindow* window);
 
diff --git a/src/nsgl_context.m b/src/nsgl_context.m
index 3f73f7a6..29430060 100644
--- a/src/nsgl_context.m
+++ b/src/nsgl_context.m
@@ -349,6 +349,53 @@ GLFWbool _glfwCreateContextNSGL(_GLFWwindow* window,
 }
 
 
+static void _glfwMakeUserContextCurrentNSGL(_GLFWusercontext* context)
+{
+    @autoreleasepool {
+
+    if (context)
+        [context->nsgl.object makeCurrentContext];
+    else
+        [NSOpenGLContext clearCurrentContext];
+
+    } // autoreleasepool
+}
+
+static void _glfwDestroyUserContextNSGL(_GLFWusercontext* context)
+{
+    @autoreleasepool {
+
+    if (context->nsgl.object)
+        [context->nsgl.object release];
+
+    } // autoreleasepool
+    free(context);
+}
+
+_GLFWusercontext* _glfwCreateUserContextNSGL(_GLFWwindow* window)
+{
+    _GLFWusercontext* context;
+
+    context = calloc(1, sizeof(_GLFWusercontext));
+    context->window = window;
+
+    context->nsgl.object =
+        [[NSOpenGLContext alloc] initWithFormat:window->context.nsgl.pixelFormat
+                                   shareContext:window->context.nsgl.object];
+    if (window->context.nsgl.object == nil)
+    {
+        _glfwInputError(GLFW_VERSION_UNAVAILABLE,
+                        "NSGL: Failed to create OpenGL user context");
+        free(context);
+        return NULL;
+    }
+
+    context->makeCurrent = _glfwMakeUserContextCurrentNSGL;
+    context->destroy = _glfwDestroyUserContextNSGL;
+
+    return context;
+}
+
 //////////////////////////////////////////////////////////////////////////
 //////                        GLFW native API                       //////
 //////////////////////////////////////////////////////////////////////////