libgimpcolor: rudimentary docs for gimp_adaptive_supersample_area()

and proper callback annotations. Also move the three callback typedefs
from gimpcolortypes.h to gimpadaptivesupersample.h because they are
needed nowhere else.

libgimpcolor/gimpadaptivesupersample.c

@@ -238,6 +238,26 @@ gimp_render_sub_pixel (gint             max_depth,
   return num_samples;
 }
 
+/**
+ * gimp_adaptive_supersample_area:
+ * @x1:             left x coordinate of the area to process.
+ * @y1:             top y coordinate of the area to process.
+ * @x2:             right x coordinate of the area to process.
+ * @y2:             bottom y coordinate of the area to process.
+ * @max_depth:      maximum depth of supersampling.
+ * @threshold:      lower threshold of pixel difference that stops
+ *                  supersampling.
+ * @render_func:    (scope call): function calculate the color value at
+ *                  given  coordinates.
+ * @render_data:    user data passed to @render_func.
+ * @put_pixel_func: (scope call): function to a pixels to a color at
+ *                  given coordinates.
+ * @put_pixel_data: user data passed to @put_pixel_func.
+ * @progress_func:  (scope call): function to report progress.
+ * @progress_data:  user data passed to @progress_func.
+ *
+ * Returns: the number of pixels processed.
+ **/
 gulong
 gimp_adaptive_supersample_area (gint              x1,
                                 gint              y1,

libgimpcolor/gimpadaptivesupersample.h

@@ -28,7 +28,18 @@ G_BEGIN_DECLS
 /* For information look into the C source or the html documentation */
 
 
-/*  adaptive supersampling function taken from LibGCK  */
+typedef void (* GimpRenderFunc)   (gdouble   x,
+                                   gdouble   y,
+                                   GimpRGB  *color,
+                                   gpointer  data);
+typedef void (* GimpPutPixelFunc) (gint      x,
+                                   gint      y,
+                                   GimpRGB  *color,
+                                   gpointer  data);
+typedef void (* GimpProgressFunc) (gint      min,
+                                   gint      max,
+                                   gint      current,
+                                   gpointer  data);
 
 
 gulong   gimp_adaptive_supersample_area (gint              x1,

libgimpcolor/gimpcolortypes.h

@@ -107,20 +107,6 @@ struct _GimpCMYK
 };
 
 
-typedef void (* GimpRenderFunc)   (gdouble   x,
-                                   gdouble   y,
-                                   GimpRGB  *color,
-                                   gpointer  data);
-typedef void (* GimpPutPixelFunc) (gint      x,
-                                   gint      y,
-                                   GimpRGB  *color,
-                                   gpointer  data);
-typedef void (* GimpProgressFunc) (gint      min,
-                                   gint      max,
-                                   gint      current,
-                                   gpointer  data);
-
-
 G_END_DECLS
 
 #endif  /* __GIMP_COLOR_TYPES_H__ */