2006-07-24 Matthew Allum <mallum@openedhand.com>

        * clutter/Makefile.am:
        * clutter/clutter-feature.c:
        * clutter/clutter-feature.h:

        Add new funcs for checking for available runtime GL
        extensions.

        * clutter/clutter-clone-texture.c:
        * clutter/clutter-texture.c:

        Add support for non power of two textures
       if GL_TEXTURE_RECTANGLE_ARB extension available ( at runtime ).
       Should lower texture memory needs a little.

1 files changed, 91 insertions, 0 deletions

diff --git a/clutter/clutter-feature.c b/clutter/clutter-feature.c
new file mode 100644
index 000000000..e1aa05572
--- /dev/null
+++ b/clutter/clutter-feature.c
@@ -0,0 +1,91 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Authored By Matthew Allum  <mallum@openedhand.com>
+ *
+ * Copyright (C) 2006 OpenedHand
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:clutter-feature
+ * @short_description: functions to query available GL features ay runtime 
+ *
+ * Functions to query available GL features ay runtime 
+ */
+
+#include "config.h"
+#include "clutter-feature.h"
+#include "string.h"
+
+static gulong __features;
+
+/* Note must be called after context created */
+static gboolean 
+check_gl_extension (const gchar *name)
+{
+  const gchar *ext;
+  gchar       *end;
+  gint         name_len, n;
+
+  ext = (const gchar*)glGetString(GL_EXTENSIONS);
+
+  if (name == NULL || ext == NULL)
+    return FALSE;
+
+  end = (gchar*)(ext + strlen(ext));
+
+  name_len = strlen(name);
+
+  while (ext < end) 
+    {
+      n = strcspn(ext, " ");
+
+      if ((name_len == n) && (!strncmp(name, ext, n)))
+	return TRUE;
+      ext += (n + 1);
+    }
+
+  return FALSE;
+}
+
+gboolean
+clutter_feature_available (gulong query)
+{
+  return (__features & query);
+}
+
+gulong 
+clutter_feature_all (void)
+{
+  return __features;
+}
+
+void
+clutter_feature_init (void)
+{
+  if (__features)
+    return;
+
+  __features = 0;
+
+  if (check_gl_extension ("GL_ARB_texture_rectangle"))
+      __features |= CLUTTER_FEATURE_TEXTURE_RECTANGLE;
+
+}