glcontext: Add a surface_attached flag

GLContexts marked as surface_attached are always attached to the surface
in make_current().
Other contexts continue to only get attached to their surface between
begin_frame() and end_frame().

All our renderer use surface-attached contexts now.
Public API only gives out non-surface-attached contexts.

The benefit here is that we can now choose whenever we want to
call make_current() because it will not cause a re-make_current() if we
call it outside vs inside the begin/end_frame() region.

Or in other words: I want to call make_current() before begin_frame()
without a performance penalty, and now I can.

gdk/gdkdisplay.c

@@ -1477,7 +1477,7 @@ gdk_display_create_gl_context (GdkDisplay  *self,
   if (!gdk_display_prepare_gl (self, error))
     return NULL;
 
-  return gdk_gl_context_new (self, NULL);
+  return gdk_gl_context_new (self, NULL, FALSE);
 }
 
 /*< private >

gdk/gdkglcontext.c

@@ -122,6 +122,7 @@ struct _GdkGLContextPrivate
   GdkGLMemoryFlags memory_flags[GDK_MEMORY_N_FORMATS];
 
   GdkGLFeatures features;
+  guint surface_attached : 1;
   guint use_khr_debug : 1;
   guint has_debug_output : 1;
   guint extensions_checked : 1;
@@ -829,20 +830,28 @@ gdk_gl_context_init (GdkGLContext *self)
 /* Must have called gdk_display_prepare_gl() before */
 GdkGLContext *
 gdk_gl_context_new (GdkDisplay *display,
-                    GdkSurface *surface)
+                    GdkSurface *surface,
+                    gboolean    surface_attached)
 {
-  GdkGLContext *shared;
+  GdkGLContextPrivate *priv;
+  GdkGLContext *shared, *result;
 
   g_assert (surface == NULL || display == gdk_surface_get_display (surface));
+  g_assert (!surface_attached || surface != NULL);
 
   /* assert gdk_display_prepare_gl() had been called */
   shared = gdk_display_get_gl_context (display);
   g_assert (shared);
 
-  return g_object_new (G_OBJECT_TYPE (shared),
+  result = g_object_new (G_OBJECT_TYPE (shared),
                          "display", display,
                          "surface", surface,
                          NULL);
+
+  priv = gdk_gl_context_get_instance_private (result);
+  priv->surface_attached = surface_attached;
+
+  return result;
 }
 
 void
@@ -1825,12 +1834,22 @@ gdk_gl_context_check_is_current (GdkGLContext *context)
 void
 gdk_gl_context_make_current (GdkGLContext *context)
 {
+  GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
   MaskedContext *current, *masked_context;
   gboolean surfaceless;
 
   g_return_if_fail (GDK_IS_GL_CONTEXT (context));
 
+  if (priv->surface_attached)
+    {
+      surfaceless = FALSE;
+    }
+  else
+    {
+G_GNUC_BEGIN_IGNORE_DEPRECATIONS
       surfaceless = !gdk_draw_context_is_in_frame (GDK_DRAW_CONTEXT (context));
+G_GNUC_END_IGNORE_DEPRECATIONS
+    }
   masked_context = mask_context (context, surfaceless);
 
   current = g_private_get (&thread_current_context);

gdk/gdkglcontextprivate.h

@@ -123,7 +123,8 @@ void                    gdk_gl_backend_use                      (GdkGLBackend
 void                    gdk_gl_context_clear_current_if_surface (GdkSurface      *surface);
 
 GdkGLContext *          gdk_gl_context_new                      (GdkDisplay             *display,
-                                                                 GdkSurface      *surface);
+                                                                 GdkSurface             *surface,
+                                                                 gboolean                surface_attached);
 
 gboolean                gdk_gl_context_is_api_allowed           (GdkGLContext           *self,
                                                                  GdkGLAPI                api,

gdk/gdksurface.c

@@ -1256,7 +1256,7 @@ gdk_surface_create_gl_context (GdkSurface   *surface,
   if (!gdk_display_prepare_gl (surface->display, error))
     return NULL;
 
-  return gdk_gl_context_new (surface->display, surface);
+  return gdk_gl_context_new (surface->display, surface, FALSE);
 }
 
 /**

gsk/gl/gskglrenderer.c

@@ -192,12 +192,12 @@ gsk_gl_renderer_realize (GskRenderer  *renderer,
   g_assert (self->context == NULL);
   g_assert (self->command_queue == NULL);
 
-  if (surface == NULL)
-    context = gdk_display_create_gl_context (display, error);
-  else
-    context = gdk_surface_create_gl_context (surface, error);
+  if (!gdk_display_prepare_gl (display, error))
+    goto failure;
 
-  if (!context || !gdk_gl_context_realize (context, error))
+  context = gdk_gl_context_new (display, surface, surface != NULL);
+
+  if (!gdk_gl_context_realize (context, error))
     goto failure;
 
   api = gdk_gl_context_get_api (context);

gsk/gpu/gsknglrenderer.c

@@ -45,14 +45,11 @@ gsk_ngl_renderer_create_context (GskGpuRenderer       *renderer,
 {
   GdkGLContext *context;
 
-  if (surface)
-    context = gdk_surface_create_gl_context (surface, error);
-  else
-    context = gdk_display_create_gl_context (display, error);
-
-  if (context == NULL)
+  if (!gdk_display_prepare_gl (display, error))
     return NULL;
 
+  context = gdk_gl_context_new (display, surface, surface != NULL);
+
   /* GLES 2 is not supported */
   gdk_gl_context_set_required_version (context, 3, 0);