Add EGL abstraction class MetaEgl

Add a MetaEgl meant to deal with EGL. It is intended to be use by EGL
based renderers and handle extension symbols loading, handle errors etc.

https://bugzilla.gnome.org/show_bug.cgi?id=773629

configure.ac

@@ -64,6 +64,7 @@ CANBERRA_GTK_VERSION=0.26
 LIBWACOM_VERSION=0.13
 
 MUTTER_PC_MODULES="
+   egl
    gtk+-3.0 >= 3.19.8
    gio-unix-2.0 >= 2.35.1
    pango >= 1.2.0

src/Makefile.am

@@ -91,6 +91,8 @@ libmutter_la_SOURCES =				\
 	backends/meta-cursor-tracker-private.h	\
 	backends/meta-cursor-renderer.c		\
 	backends/meta-cursor-renderer.h		\
+	backends/meta-egl.c			\
+	backneds/meta-egl.h			\
 	backends/meta-display-config-shared.h	\
 	backends/meta-idle-monitor.c		\
 	backends/meta-idle-monitor-private.h	\

src/backends/meta-backend-private.h

@@ -35,6 +35,7 @@
 #include "meta-cursor-renderer.h"
 #include "meta-monitor-manager-private.h"
 #include "meta-input-settings-private.h"
+#include "backends/meta-egl.h"
 #include "backends/meta-pointer-constraint.h"
 #include "backends/meta-renderer.h"
 #include "core/util-private.h"
@@ -117,6 +118,7 @@ MetaIdleMonitor * meta_backend_get_idle_monitor (MetaBackend *backend,
 MetaMonitorManager * meta_backend_get_monitor_manager (MetaBackend *backend);
 MetaCursorRenderer * meta_backend_get_cursor_renderer (MetaBackend *backend);
 MetaRenderer * meta_backend_get_renderer (MetaBackend *backend);
+MetaEgl * meta_backend_get_egl (MetaBackend *backend);
 
 gboolean meta_backend_grab_device (MetaBackend *backend,
                                    int          device_id,

src/backends/meta-backend.c

@@ -65,6 +65,7 @@ struct _MetaBackendPrivate
   MetaCursorRenderer *cursor_renderer;
   MetaInputSettings *input_settings;
   MetaRenderer *renderer;
+  MetaEgl *egl;
 
   ClutterBackend *clutter_backend;
   ClutterActor *stage;
@@ -411,6 +412,8 @@ meta_backend_initable_init (GInitable     *initable,
   MetaBackend *backend = META_BACKEND (initable);
   MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
 
+  priv->egl = g_object_new (META_TYPE_EGL, NULL);
+
   priv->renderer = META_BACKEND_GET_CLASS (backend)->create_renderer (backend);
   if (!priv->renderer)
     {
@@ -483,6 +486,16 @@ MetaRenderer * meta_backend_get_renderer (MetaBackend *backend)
   return priv->renderer;
 }
 
+/**
+ * meta_backend_get_egl: (skip)
+ */
+MetaEgl * meta_backend_get_egl (MetaBackend *backend)
+{
+  MetaBackendPrivate *priv = meta_backend_get_instance_private (backend);
+
+  return priv->egl;
+}
+
 /**
  * meta_backend_grab_device: (skip)
  */

src/backends/meta-egl.c

@@ -0,0 +1,137 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2016 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl@gmail.com>
+ */
+
+#include "config.h"
+
+#include "backends/meta-egl.h"
+
+#include <EGL/egl.h>
+#include <gio/gio.h>
+#include <glib.h>
+#include <glib-object.h>
+
+struct _MetaEgl
+{
+  GObject parent;
+};
+
+G_DEFINE_TYPE (MetaEgl, meta_egl, G_TYPE_OBJECT)
+
+static const char *
+get_egl_error_str (void)
+{
+  EGLint error_number;
+
+  error_number = eglGetError ();
+
+  switch (error_number)
+    {
+    case EGL_SUCCESS:
+      return "The last function succeeded without error.";
+      break;
+    case EGL_NOT_INITIALIZED:
+      return "EGL is not initialized, or could not be initialized, for the specified EGL display connection.";
+      break;
+    case EGL_BAD_ACCESS:
+      return "EGL cannot access a requested resource (for example a context is bound in another thread).";
+      break;
+    case EGL_BAD_ALLOC:
+      return "EGL failed to allocate resources for the requested operation.";
+      break;
+    case EGL_BAD_ATTRIBUTE:
+      return "An unrecognized attribute or attribute value was passed in the attribute list.";
+      break;
+    case EGL_BAD_CONTEXT:
+      return "An EGLContext argument does not name a valid EGL rendering context.";
+      break;
+    case EGL_BAD_CONFIG:
+      return "An EGLConfig argument does not name a valid EGL frame buffer configuration.";
+      break;
+    case EGL_BAD_CURRENT_SURFACE:
+      return "The current surface of the calling thread is a window, pixel buffer or pixmap that is no longer valid.";
+      break;
+    case EGL_BAD_DISPLAY:
+      return "An EGLDisplay argument does not name a valid EGL display connection.";
+      break;
+    case EGL_BAD_SURFACE:
+      return "An EGLSurface argument does not name a valid surface (window, pixel buffer or pixmap) configured for GL rendering.";
+      break;
+    case EGL_BAD_MATCH:
+      return "Arguments are inconsistent (for example, a valid context requires buffers not supplied by a valid surface).";
+      break;
+    case EGL_BAD_PARAMETER:
+      return "One or more argument values are invalid.";
+      break;
+    case EGL_BAD_NATIVE_PIXMAP:
+      return "A NativePixmapType argument does not refer to a valid native pixmap.";
+      break;
+    case EGL_BAD_NATIVE_WINDOW:
+      return "A NativeWindowType argument does not refer to a valid native window.";
+      break;
+    case EGL_CONTEXT_LOST:
+      return "A power management event has occurred. The application must destroy all contexts and reinitialise OpenGL ES state and objects to continue rendering. ";
+      break;
+    default:
+      return "Unknown error";
+      break;
+    }
+}
+
+static void
+set_egl_error (GError **error)
+{
+  const char *error_str;
+
+  error_str = get_egl_error_str ();
+  g_set_error (error, G_IO_ERROR,
+               G_IO_ERROR_FAILED,
+               error_str);
+}
+
+EGLDisplay
+meta_egl_get_display (MetaEgl             *egl,
+                      EGLNativeDisplayType display_id,
+                      GError             **error)
+{
+  EGLDisplay display;
+
+  display = eglGetDisplay (display_id);
+  if (display == EGL_NO_DISPLAY)
+    {
+      set_egl_error (error);
+      return EGL_NO_DISPLAY;
+    }
+
+  return display;
+}
+
+static void
+meta_egl_init (MetaEgl *egl)
+{
+}
+
+static void
+meta_egl_class_init (MetaEglClass *klass)
+{
+}

src/backends/meta-egl.h

@@ -0,0 +1,38 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/*
+ * Copyright (C) 2016 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ *
+ * Written by:
+ *     Jonas Ådahl <jadahl@gmail.com>
+ */
+
+#ifndef META_EGL_H
+#define META_EGL_H
+
+#include <EGL/egl.h>
+#include <glib-object.h>
+
+#define META_TYPE_EGL (meta_egl_get_type ())
+G_DECLARE_FINAL_TYPE (MetaEgl, meta_egl, META, EGL, GObject)
+
+EGLDisplay meta_egl_get_display (MetaEgl             *egl,
+                                 EGLNativeDisplayType display_id,
+                                 GError             **error);
+
+#endif /* META_EGL_H */