From: Benjamin Otte <otte@redhat.com>
Date: Sat, 12 Jun 2021 09:13:22 +0000 (+0200)
Subject: glx: Remove Visual cache
X-Git-Tag: archive/raspbian/4.4.1+ds1-2+rpi1^2~18^2~3^2~9^2~37
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=62bac44a2108ceadbf659ce56f64bf14429fc5d2;p=gtk4.git

glx: Remove Visual cache

1. We're using EGL most of the time anyway, so if we wanted to cache
   things, we'd need to port it there.
2. Our GL handling is massively configurable, so determining when to use
   the cache and when not is a challenge.
3. It makes startup nondeterministic and depend on whether a GTK4 app
   has previously been started on this display and nobody thinks about
   that when debugging.
4. The only benefit of the caching is delaying GL initialization - which
   made sense in GTK3 where almost no app used GL but doesn't make sense
   in GTK4 where almost every app uses GL.

So unless I find a big benefit to reintroducing it, this cache will be
gone for good.
---

diff --git a/gdk/x11/gdkglcontext-glx.c b/gdk/x11/gdkglcontext-glx.c
index 3bdfe431ea..4ebc30bd89 100644
--- a/gdk/x11/gdkglcontext-glx.c
+++ b/gdk/x11/gdkglcontext-glx.c
@@ -947,64 +947,6 @@ pick_better_visual_for_gl (GdkX11Screen *x11_screen,
   return compatible;
 }
 
-#define STRINGIFY_WITHOUT_BRACKETS(x) G_STRINGIFY x
-#define CACHED_VISUAL_ATOM_NAME "GDK" STRINGIFY_WITHOUT_BRACKETS(GDK_MAJOR_VERSION) "_GLX_VISUAL"
-
-static VisualID
-get_cached_gl_visual (GdkDisplay *display)
-{
-  Atom type_return;
-  int format_return;
-  gulong nitems_return;
-  gulong bytes_after_return;
-  guchar *data = NULL;
-  Display *dpy;
-  VisualID result;
-
-  dpy = gdk_x11_display_get_xdisplay (display);
-  result = 0;
-
-  gdk_x11_display_error_trap_push (display);
-  if (XGetWindowProperty (dpy, DefaultRootWindow (dpy),
-                          gdk_x11_get_xatom_by_name_for_display (display, CACHED_VISUAL_ATOM_NAME),
-                          0, 1, False, XA_VISUALID, &type_return,
-                          &format_return, &nitems_return,
-                          &bytes_after_return, &data) == Success)
-    {
-      if (type_return == XA_VISUALID &&
-          format_return == 32 &&
-          nitems_return == 1 &&
-          data != NULL)
-        {
-          result = *(unsigned long *) data;
-        }
-    }
-  gdk_x11_display_error_trap_pop_ignored (display);
-
-  if (data)
-    XFree (data);
-
-  return result;
-}
-
-static void
-save_cached_gl_visual (GdkDisplay *display, VisualID visual)
-{
-  unsigned long visualdata[1];
-  Display *dpy;
-
-  dpy = gdk_x11_display_get_xdisplay (display);
-
-  visualdata[0] = visual;
-
-  gdk_x11_display_error_trap_push (display);
-  XChangeProperty (dpy, DefaultRootWindow (dpy),
-                   gdk_x11_get_xatom_by_name_for_display (display, CACHED_VISUAL_ATOM_NAME),
-                   XA_VISUALID, 32, PropModeReplace,
-                   (unsigned char *) visualdata, 2);
-  gdk_x11_display_error_trap_pop_ignored (display);
-}
-
 static void
 gdk_x11_screen_update_visuals_for_glx (GdkX11Screen *x11_screen)
 {
@@ -1013,30 +955,11 @@ gdk_x11_screen_update_visuals_for_glx (GdkX11Screen *x11_screen)
   Display *dpy;
   struct glvisualinfo *gl_info;
   int i;
-  int rgba_visual_id;
 
   display = x11_screen->display;
   display_x11 = GDK_X11_DISPLAY (display);
   dpy = gdk_x11_display_get_xdisplay (display);
 
-  /* We save the default visuals as a property on the root window to avoid
-     having to initialize GL each time, as it may not be used later. */
-  rgba_visual_id = get_cached_gl_visual (display);
-  if (rgba_visual_id)
-    {
-      for (i = 0; i < x11_screen->nvisuals; i++)
-        {
-          GdkX11Visual *visual = x11_screen->visuals[i];
-          int visual_id = gdk_x11_visual_get_xvisual (visual)->visualid;
-
-          if (visual_id == rgba_visual_id)
-            {
-              x11_screen->rgba_visual = visual;
-              return;
-            }
-        }
-    }
-
   gl_info = g_new0 (struct glvisualinfo, x11_screen->nvisuals);
 
   for (i = 0; i < x11_screen->nvisuals; i++)
@@ -1071,10 +994,7 @@ gdk_x11_screen_update_visuals_for_glx (GdkX11Screen *x11_screen)
     }
 
   if (x11_screen->rgba_visual)
-    {
-      x11_screen->rgba_visual = pick_better_visual_for_gl (x11_screen, gl_info, x11_screen->rgba_visual);
-      save_cached_gl_visual (display, gdk_x11_visual_get_xvisual (x11_screen->rgba_visual)->visualid);
-    }
+    x11_screen->rgba_visual = pick_better_visual_for_gl (x11_screen, gl_info, x11_screen->rgba_visual);
 
   g_free (gl_info);
 }