[gtk/wip/otte/gleanup: 2/7] x11: Store the EGL config in the display

[Benjamin Otte <otte src gnome org>]

commit 93d1dc752d047d81c5c0ea6a5f32e412a1e0d6cc
Author: Benjamin Otte <otte redhat com>
Date:   Wed Jun 9 13:42:19 2021 +0200

    x11: Store the EGL config in the display
    
    We only have one config, because we use the same Visual everywhere.
    Store this config in the GdkDisplayX11 struct for easy access.
    
    Also do this on initialize, because if creating the config fails, we
    want to switch to GLX instead of failing to do GL at all.
    
    This also simplifies a lot of code as we can share Visual, Colormap, etc
    across surfaces.

 gdk/x11/gdkdisplay-x11.h   |   1 +
 gdk/x11/gdkglcontext-egl.c | 133 +++++++++++++++++++--------------------------
 2 files changed, 57 insertions(+), 77 deletions(-)
---
diff --git a/gdk/x11/gdkdisplay-x11.h b/gdk/x11/gdkdisplay-x11.h
index 842666b4a3..977c4ac4ac 100644
--- a/gdk/x11/gdkdisplay-x11.h
+++ b/gdk/x11/gdkdisplay-x11.h
@@ -139,6 +139,7 @@ struct _GdkX11Display
   /* EGL information */
   /* We use gpointer here so we don't have to pull in EGL headers (which glx doesn't like) */
   /* EGLDisplay */ gpointer egl_display;
+  /* EGLConfig */ gpointer egl_config;
   int egl_version;
 
   /* Translation between X server time and system-local monotonic time */
diff --git a/gdk/x11/gdkglcontext-egl.c b/gdk/x11/gdkglcontext-egl.c
index 071c17a557..fc1aaf6ad2 100644
--- a/gdk/x11/gdkglcontext-egl.c
+++ b/gdk/x11/gdkglcontext-egl.c
@@ -35,7 +35,6 @@ struct _GdkX11GLContextEGL
 {
   GdkX11GLContext parent_instance;
 
-  EGLConfig egl_config;
   EGLContext egl_context;
 };
 
@@ -143,6 +142,41 @@ gdk_x11_display_create_egl_display (GdkX11Display *self)
   self->egl_display = eglGetDisplay ((EGLNativeDisplayType) dpy);
 }
 
+#define MAX_EGL_ATTRS   30
+
+static void
+gdk_x11_display_create_egl_config (GdkX11Display *display)
+{
+  GdkX11Display *self = GDK_X11_DISPLAY (display);
+  EGLint attrs[MAX_EGL_ATTRS];
+  EGLint count;
+  int i = 0;
+
+  attrs[i++] = EGL_SURFACE_TYPE;
+  attrs[i++] = EGL_WINDOW_BIT;
+
+  attrs[i++] = EGL_COLOR_BUFFER_TYPE;
+  attrs[i++] = EGL_RGB_BUFFER;
+
+  attrs[i++] = EGL_RED_SIZE;
+  attrs[i++] = 8;
+  attrs[i++] = EGL_GREEN_SIZE;
+  attrs[i++] = 8;
+  attrs[i++] = EGL_BLUE_SIZE;
+  attrs[i++] = 8;
+  attrs[i++] = EGL_ALPHA_SIZE;
+  attrs[i++] = 8;
+
+  attrs[i++] = EGL_NONE;
+  g_assert (i < MAX_EGL_ATTRS);
+
+  /* Pick first valid configuration that the driver returns us */
+  if (!eglChooseConfig (self->egl_display, attrs, &display->egl_config, 1, &count) && count >= 1)
+    display->egl_config = NULL;
+}
+
+#undef MAX_EGL_ATTRS
+
 static XVisualInfo *
 get_visual_info_for_egl_config (GdkDisplay *display,
                                 EGLConfig   egl_config)
@@ -193,6 +227,7 @@ static EGLSurface
 gdk_x11_display_get_egl_dummy_surface (GdkDisplay *display,
                                        EGLConfig   egl_config)
 {
+  GdkX11Display *display_x11 = GDK_X11_DISPLAY (display);
   DrawableInfo *info;
   XVisualInfo *xvisinfo;
   XSetWindowAttributes attrs;
@@ -212,10 +247,7 @@ gdk_x11_display_get_egl_dummy_surface (GdkDisplay *display,
   info->egl_config = egl_config;
 
   attrs.override_redirect = True;
-  attrs.colormap = XCreateColormap (info->xdisplay,
-                                    DefaultRootWindow (info->xdisplay),
-                                    xvisinfo->visual,
-                                    AllocNone);
+  attrs.colormap = gdk_x11_display_get_window_colormap (display_x11);
   attrs.border_pixel = 0;
 
   info->dummy_xwin =
@@ -223,9 +255,9 @@ gdk_x11_display_get_egl_dummy_surface (GdkDisplay *display,
                    DefaultRootWindow (info->xdisplay),
                    -100, -100, 1, 1,
                    0,
-                   xvisinfo->depth,
+                   gdk_x11_display_get_window_depth (display_x11),
                    CopyFromParent,
-                   xvisinfo->visual,
+                   gdk_x11_display_get_window_visual (display_x11),
                    CWOverrideRedirect | CWColormap | CWBorderPixel,
                    &attrs);
 
@@ -243,8 +275,7 @@ gdk_x11_display_get_egl_dummy_surface (GdkDisplay *display,
 }
 
 static EGLSurface
-gdk_x11_surface_get_egl_surface (GdkSurface *surface,
-                                 EGLConfig   config)
+gdk_x11_surface_get_egl_surface (GdkSurface *surface)
 {
   GdkDisplay *display = gdk_surface_get_display (surface);
   GdkX11Display *display_x11 = GDK_X11_DISPLAY (display);
@@ -256,9 +287,9 @@ gdk_x11_surface_get_egl_surface (GdkSurface *surface,
 
   info = g_new0 (DrawableInfo, 1);
   info->egl_display = display_x11->egl_display;
-  info->egl_config = config;
+  info->egl_config = display_x11->egl_config;
   info->egl_surface =
-    eglCreateWindowSurface (info->egl_display, config,
+    eglCreateWindowSurface (info->egl_display, info->egl_config,
                             (EGLNativeWindowType) gdk_x11_surface_get_xid (surface),
                             NULL);
 
@@ -274,7 +305,6 @@ gdk_x11_gl_context_egl_end_frame (GdkDrawContext *draw_context,
                                   cairo_region_t *painted)
 {
   GdkGLContext *context = GDK_GL_CONTEXT (draw_context);
-  GdkX11GLContextEGL *context_egl = GDK_X11_GL_CONTEXT_EGL (context);
   GdkSurface *surface = gdk_gl_context_get_surface (context);
   GdkDisplay *display = gdk_surface_get_display (surface);
   GdkX11Display *display_x11 = GDK_X11_DISPLAY (display);
@@ -286,7 +316,7 @@ gdk_x11_gl_context_egl_end_frame (GdkDrawContext *draw_context,
 
   gdk_gl_context_make_current (context);
 
-  egl_surface = gdk_x11_surface_get_egl_surface (surface, context_egl->egl_config);
+  egl_surface = gdk_x11_surface_get_egl_surface (surface);
 
   gdk_profiler_add_mark (GDK_PROFILER_CURRENT_TIME, 0, "x11", "swap buffers");
   if (display_x11->has_egl_swap_buffers_with_damage)
@@ -332,16 +362,14 @@ gdk_x11_gl_context_egl_get_damage (GdkGLContext *context)
     {
       GdkSurface *surface = gdk_draw_context_get_surface (GDK_DRAW_CONTEXT (context));
       GdkGLContext *shared = gdk_gl_context_get_shared_context (context);
-      GdkX11GLContextEGL *shared_egl;
       EGLSurface egl_surface;
       int buffer_age = 0;
 
       shared = gdk_gl_context_get_shared_context (context);
       if (shared == NULL)
         shared = context;
-      shared_egl = GDK_X11_GL_CONTEXT_EGL (shared);
 
-      egl_surface = gdk_x11_surface_get_egl_surface (surface, shared_egl->egl_config);
+      egl_surface = gdk_x11_surface_get_egl_surface (surface);
       gdk_gl_context_make_current (shared);
 
       eglQuerySurface (display_x11->egl_display,
@@ -462,7 +490,7 @@ gdk_x11_gl_context_egl_realize (GdkGLContext  *context,
 
   context_egl->egl_context =
     eglCreateContext (display_x11->egl_display,
-                      context_egl->egl_config,
+                      display_x11->egl_config,
                       share != NULL
                         ? GDK_X11_GL_CONTEXT_EGL (share)->egl_context
                         : shared_data_context != NULL
@@ -487,7 +515,7 @@ gdk_x11_gl_context_egl_realize (GdkGLContext  *context,
 
       context_egl->egl_context =
         eglCreateContext (display_x11->egl_display,
-                          context_egl->egl_config,
+                          display_x11->egl_config,
                           share != NULL
                             ? GDK_X11_GL_CONTEXT_EGL (share)->egl_context
                             : shared_data_context != NULL
@@ -579,6 +607,14 @@ gdk_x11_display_init_egl (GdkX11Display *self)
       return FALSE;
     }
 
+  gdk_x11_display_create_egl_config (self);
+  if (self->egl_config == NULL)
+    {
+      eglTerminate (self->egl_display);
+      self->egl_display = NULL;
+      return FALSE;
+    }
+
   /* While NVIDIA might support EGL, it might very well not support
    * all the EGL subset we rely on; we should be looking at more
    * EGL extensions, but for the time being, this is a blanket
@@ -624,76 +660,19 @@ gdk_x11_display_init_egl (GdkX11Display *self)
   return TRUE;
 }
 
-#define MAX_EGL_ATTRS   30
-
-static gboolean
-find_eglconfig_for_display (GdkDisplay  *display,
-                            EGLConfig   *egl_config_out,
-                            GError     **error)
-{
-  GdkX11Display *self = GDK_X11_DISPLAY (display);
-  EGLint attrs[MAX_EGL_ATTRS];
-  EGLint count;
-  EGLConfig egl_config;
-  int i = 0;
-
-  attrs[i++] = EGL_SURFACE_TYPE;
-  attrs[i++] = EGL_WINDOW_BIT;
-
-  attrs[i++] = EGL_COLOR_BUFFER_TYPE;
-  attrs[i++] = EGL_RGB_BUFFER;
-
-  attrs[i++] = EGL_RED_SIZE;
-  attrs[i++] = 8;
-  attrs[i++] = EGL_GREEN_SIZE;
-  attrs[i++] = 8;
-  attrs[i++] = EGL_BLUE_SIZE;
-  attrs[i++] = 8;
-  attrs[i++] = EGL_ALPHA_SIZE;
-  attrs[i++] = 8;
-
-  attrs[i++] = EGL_NONE;
-  g_assert (i < MAX_EGL_ATTRS);
-
-  /* Pick first valid configuration that the driver returns us */
-  if (!eglChooseConfig (self->egl_display, attrs, &egl_config, 1, &count) || count < 1)
-    {
-      g_set_error_literal (error, GDK_GL_ERROR,
-                           GDK_GL_ERROR_UNSUPPORTED_FORMAT,
-                           _("No available configurations for the given pixel format"));
-      return FALSE;
-    }
-
-  g_assert (egl_config_out);
-  *egl_config_out = egl_config;
-
-  return TRUE;
-}
-
-#undef MAX_EGL_ATTRS
-
 GdkX11GLContext *
 gdk_x11_gl_context_egl_new (GdkSurface    *surface,
                             gboolean       attached,
                             GdkGLContext  *share,
                             GError       **error)
 {
-  GdkDisplay *display;
   GdkX11GLContextEGL *context;
-  EGLConfig egl_config;
-
-  display = gdk_surface_get_display (surface);
-
-  if (!find_eglconfig_for_display (display, &egl_config, error))
-    return NULL;
 
   context = g_object_new (GDK_TYPE_X11_GL_CONTEXT_EGL,
                           "surface", surface,
                           "shared-context", share,
                           NULL);
 
-  context->egl_config = egl_config;
-
   return GDK_X11_GL_CONTEXT (context);
 }
 
@@ -723,13 +702,13 @@ gdk_x11_gl_context_egl_make_current (GdkDisplay   *display,
   surface = gdk_gl_context_get_surface (context);
 
   if (context_x11->is_attached || gdk_draw_context_is_in_frame (GDK_DRAW_CONTEXT (context)))
-    egl_surface = gdk_x11_surface_get_egl_surface (surface, context_egl->egl_config);
+    egl_surface = gdk_x11_surface_get_egl_surface (surface);
   else
     {
       if (display_x11->has_egl_surfaceless_context)
         egl_surface = EGL_NO_SURFACE;
       else
-        egl_surface = gdk_x11_display_get_egl_dummy_surface (display, context_egl->egl_config);
+        egl_surface = gdk_x11_display_get_egl_dummy_surface (display, display_x11->egl_config);
     }
 
   GDK_DISPLAY_NOTE (display, OPENGL,