Documentation: C API comments in include/

include/c/sk_maskfilter.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 // EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL EXPERIMENTAL
 // DO NOT USE -- FOR INTERNAL TESTING ONLY
 
 #ifndef sk_maskfilter_DEFINED
 #define sk_maskfilter_DEFINED
 
 #include "sk_types.h"
 
 typedef enum {
     NORMAL_SK_BLUR_STYLE,   //!< fuzzy inside and outside
     SOLID_SK_BLUR_STYLE,    //!< solid inside, fuzzy outside
     OUTER_SK_BLUR_STYLE,    //!< nothing inside, fuzzy outside
     INNER_SK_BLUR_STYLE,    //!< fuzzy inside, nothing outside
 } sk_blurstyle_t;
 
 SK_C_PLUS_PLUS_BEGIN_GUARD
 
+/**
+    Increment the reference count on the given sk_maskfilter_t. Must be
+    balanced by a call to sk_maskfilter_unref().
+*/
 void sk_maskfilter_ref(sk_maskfilter_t*);
+/**
+    Decrement the reference count. If the reference count is 1 before
+    the decrement, then release both the memory holding the
+    sk_maskfilter_t and any other associated resources.  New
+    sk_maskfilter_t are created with a reference count of 1.
+*/
 void sk_maskfilter_unref(sk_maskfilter_t*);
 
+/**
+    Create a blur maskfilter.
+    @param sk_blurstyle_t The SkBlurStyle to use
+    @param sigma Standard deviation of the Gaussian blur to apply. Must be > 0.
+*/
 sk_maskfilter_t* sk_maskfilter_new_blur(sk_blurstyle_t, float sigma);
 
 SK_C_PLUS_PLUS_END_GUARD
 
 #endif