cogl: Port Color to GBoxed

Also removes a part of the docs in the private structure as it ends up
being detected as the docs for the public structure causing conflict

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3193>

cogl/cogl/cogl-color.c

@@ -35,9 +35,12 @@
 #include "cogl/cogl-util.h"
 #include "cogl/cogl-color.h"
 #include "cogl/cogl-color-private.h"
-#include "cogl/cogl-gtype-private.h"
 
-COGL_GTYPE_DEFINE_BOXED (Color, color, cogl_color_copy, cogl_color_free);
+G_DEFINE_BOXED_TYPE (CoglColor,
+                     cogl_color,
+                     cogl_color_copy,
+                     cogl_color_free)
+
 
 CoglColor *
 cogl_color_new (void)

cogl/cogl/cogl-color.h

@@ -35,8 +35,9 @@
 #endif
 
 /**
- * SECTION:cogl-color
- * @short_description: A generic color definition
+ * CoglColor:
+ *
+ * A generic color definition
  *
  * #CoglColor is a simple structure holding the definition of a color such
  * that it can be efficiently used by GL
@@ -49,13 +50,15 @@
 
 G_BEGIN_DECLS
 
+#define COGL_TYPE_COLOR (cogl_color_get_type ())
+
 /**
- * cogl_color_get_gtype:
+ * cogl_color_get_type:
  *
  * Returns: a #GType that can be used with the GLib type system.
  */
 COGL_EXPORT
-GType cogl_color_get_gtype (void);
+GType cogl_color_get_type (void);
 
 /**
  * cogl_color_new:

cogl/cogl/cogl-types.h

@@ -121,17 +121,6 @@ typedef enum
   COGL_OFFSCREEN_BUFFER   = (1 << 2)
 } CoglBufferTarget;
 
-/**
- * CoglColor:
- * @red: amount of red
- * @green: amount of green
- * @blue: amount of green
- * @alpha: alpha
- *
- * A structure for holding a color definition. The contents of
- * the CoglColor structure are private and should never by accessed
- * directly.
- */
 struct _CoglColor
 {
   /*< private >*/