[docs] Add gtkdoc comments to hb-buffer

src/hb-buffer.cc

@@ -37,8 +37,9 @@
  * @short_description: Input and output buffers
  * @include: hb.h
  *
- * Buffers serve dual role in HarfBuzz; they hold the input characters that are
- * passed to hb_shape(), and after shaping they hold the output glyphs.
+ * Buffers serve a dual role in HarfBuzz; before shaping, they hold
+ * the input characters that are passed to hb_shape(), and after
+ * shaping they hold the output glyphs.
  **/
 
 
@@ -705,9 +706,9 @@ hb_buffer_create ()
 /**
  * hb_buffer_get_empty:
  *
+ * Fetches an empty #hb_buffer_t.
  *
- *
- * Return value: (transfer full):
+ * Return value: (transfer full): The empty buffer
  *
  * Since: 0.9.2
  **/
@@ -719,7 +720,7 @@ hb_buffer_get_empty ()
 
 /**
  * hb_buffer_reference: (skip)
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Increases the reference count on @buffer by one. This prevents @buffer from
  * being destroyed until a matching call to hb_buffer_destroy() is made.
@@ -737,7 +738,7 @@ hb_buffer_reference (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_destroy: (skip)
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Deallocate the @buffer.
  * Decreases the reference count on @buffer by one. If the result is zero, then
@@ -764,15 +765,15 @@ hb_buffer_destroy (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_user_data: (skip)
- * @buffer: an #hb_buffer_t.
- * @key:
- * @data:
- * @destroy:
- * @replace:
- *
+ * @buffer: An #hb_buffer_t
+ * @key: The user-data key
+ * @data: A pointer to the user data
+ * @destroy: A callback to call when @data is not needed anymore
+ * @replace: Whether to replace an existing data with the same key
  *
+ * Attaches a user-data key/data pair to the specified buffer. 
  *
- * Return value:
+ * Return value: %true if success, false otherwise
  *
  * Since: 0.9.2
  **/
@@ -788,12 +789,13 @@ hb_buffer_set_user_data (hb_buffer_t        *buffer,
 
 /**
  * hb_buffer_get_user_data: (skip)
- * @buffer: an #hb_buffer_t.
- * @key:
+ * @buffer: An #hb_buffer_t
+ * @key: The user-data key to query
  *
+ * Fetches the user data associated with the specified key,
+ * attached to the specified buffer.
  *
- *
- * Return value:
+ * Return value: A pointer to the user data
  *
  * Since: 0.9.2
  **/
@@ -807,11 +809,11 @@ hb_buffer_get_user_data (hb_buffer_t        *buffer,
 
 /**
  * hb_buffer_set_content_type:
- * @buffer: an #hb_buffer_t.
- * @content_type: the type of buffer contents to set
+ * @buffer: An #hb_buffer_t
+ * @content_type: The type of buffer contents to set
  *
- * Sets the type of @buffer contents, buffers are either empty, contain
- * characters (before shaping) or glyphs (the result of shaping).
+ * Sets the type of @buffer contents. Buffers are either empty, contain
+ * characters (before shaping), or contain glyphs (the result of shaping).
  *
  * Since: 0.9.5
  **/
@@ -824,12 +826,13 @@ hb_buffer_set_content_type (hb_buffer_t              *buffer,
 
 /**
  * hb_buffer_get_content_type:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
- * see hb_buffer_set_content_type().
+ * Fetches the type of @buffer contents. Buffers are either empty, contain
+ * characters (before shaping), or contain glyphs (the result of shaping).
  *
  * Return value:
- * The type of @buffer contents.
+ * The type of @buffer contents
  *
  * Since: 0.9.5
  **/
@@ -842,10 +845,11 @@ hb_buffer_get_content_type (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_unicode_funcs:
- * @buffer: an #hb_buffer_t.
- * @unicode_funcs:
- *
+ * @buffer: An #hb_buffer_t
+ * @unicode_funcs: The Unicode-functions structure
  *
+ * Sets the Unicode-functions structure of a buffer to
+ * @unicode_funcs.
  *
  * Since: 0.9.2
  **/
@@ -866,11 +870,11 @@ hb_buffer_set_unicode_funcs (hb_buffer_t        *buffer,
 
 /**
  * hb_buffer_get_unicode_funcs:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
+ * Fetches the Unicode-functions structure of a buffer.
  *
- *
- * Return value:
+ * Return value: The Unicode-functions structure
  *
  * Since: 0.9.2
  **/
@@ -882,7 +886,7 @@ hb_buffer_get_unicode_funcs (hb_buffer_t        *buffer)
 
 /**
  * hb_buffer_set_direction:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  * @direction: the #hb_direction_t of the @buffer
  *
  * Set the text flow direction of the buffer. No shaping can happen without
@@ -908,7 +912,7 @@ hb_buffer_set_direction (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_get_direction:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * See hb_buffer_set_direction()
  *
@@ -925,8 +929,8 @@ hb_buffer_get_direction (hb_buffer_t    *buffer)
 
 /**
  * hb_buffer_set_script:
- * @buffer: an #hb_buffer_t.
- * @script: an #hb_script_t to set.
+ * @buffer: An #hb_buffer_t
+ * @script: An #hb_script_t to set.
  *
  * Sets the script of @buffer to @script.
  *
@@ -952,12 +956,12 @@ hb_buffer_set_script (hb_buffer_t *buffer,
 
 /**
  * hb_buffer_get_script:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
- * See hb_buffer_set_script().
+ * Fetches the script of @buffer.
  *
  * Return value:
- * The #hb_script_t of the @buffer.
+ * The #hb_script_t of the @buffer
  *
  * Since: 0.9.2
  **/
@@ -969,8 +973,8 @@ hb_buffer_get_script (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_language:
- * @buffer: an #hb_buffer_t.
- * @language: an hb_language_t to set.
+ * @buffer: An #hb_buffer_t
+ * @language: An hb_language_t to set
  *
  * Sets the language of @buffer to @language.
  *
@@ -996,7 +1000,7 @@ hb_buffer_set_language (hb_buffer_t   *buffer,
 
 /**
  * hb_buffer_get_language:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * See hb_buffer_set_language().
  *
@@ -1013,8 +1017,8 @@ hb_buffer_get_language (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_segment_properties:
- * @buffer: an #hb_buffer_t.
- * @props: an #hb_segment_properties_t to use.
+ * @buffer: An #hb_buffer_t
+ * @props: An #hb_segment_properties_t to use
  *
  * Sets the segment properties of the buffer, a shortcut for calling
  * hb_buffer_set_direction(), hb_buffer_set_script() and
@@ -1034,8 +1038,8 @@ hb_buffer_set_segment_properties (hb_buffer_t *buffer,
 
 /**
  * hb_buffer_get_segment_properties:
- * @buffer: an #hb_buffer_t.
- * @props: (out): the output #hb_segment_properties_t.
+ * @buffer: An #hb_buffer_t
+ * @props: (out): The output #hb_segment_properties_t
  *
  * Sets @props to the #hb_segment_properties_t of @buffer.
  *
@@ -1051,8 +1055,8 @@ hb_buffer_get_segment_properties (hb_buffer_t *buffer,
 
 /**
  * hb_buffer_set_flags:
- * @buffer: an #hb_buffer_t.
- * @flags: the buffer flags to set.
+ * @buffer: An #hb_buffer_t
+ * @flags: The buffer flags to set
  *
  * Sets @buffer flags to @flags. See #hb_buffer_flags_t.
  *
@@ -1070,12 +1074,12 @@ hb_buffer_set_flags (hb_buffer_t       *buffer,
 
 /**
  * hb_buffer_get_flags:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
- * See hb_buffer_set_flags().
+ * Fetches the #hb_buffer_flags_t for @buffer.
  *
  * Return value:
- * The @buffer flags.
+ * The @buffer flags
  *
  * Since: 0.9.7
  **/
@@ -1087,10 +1091,12 @@ hb_buffer_get_flags (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_cluster_level:
- * @buffer: an #hb_buffer_t.
- * @cluster_level:
- *
+ * @buffer: An #hb_buffer_t
+ * @cluster_level: The cluster level to set on the buffer
  *
+ * Sets the cluster level of a buffer. The #hb_buffer_cluster_level_t
+ * dictates one aspect of how HarfBuzz will treat non-base characters 
+ * during shaping.
  *
  * Since: 0.9.42
  **/
@@ -1106,11 +1112,13 @@ hb_buffer_set_cluster_level (hb_buffer_t               *buffer,
 
 /**
  * hb_buffer_get_cluster_level:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
+ * Fetches the cluster level of a buffer. The #hb_buffer_cluster_level_t
+ * dictates one aspect of how HarfBuzz will treat non-base characters 
+ * during shaping.
  *
- *
- * Return value:
+ * Return value: The cluster level of @buffer
  *
  * Since: 0.9.42
  **/
@@ -1123,7 +1131,7 @@ hb_buffer_get_cluster_level (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_set_replacement_codepoint:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  * @replacement: the replacement #hb_codepoint_t
  *
  * Sets the #hb_codepoint_t that replaces invalid entries for a given encoding
@@ -1145,12 +1153,13 @@ hb_buffer_set_replacement_codepoint (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_get_replacement_codepoint:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
- * See hb_buffer_set_replacement_codepoint().
+ * Fetches the #hb_codepoint_t that replaces invalid entries for a given encoding
+ * when adding text to @buffer.
  *
  * Return value:
- * The @buffer replacement #hb_codepoint_t.
+ * The @buffer replacement #hb_codepoint_t
  *
  * Since: 0.9.31
  **/
@@ -1163,7 +1172,7 @@ hb_buffer_get_replacement_codepoint (hb_buffer_t    *buffer)
 
 /**
  * hb_buffer_set_invisible_glyph:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  * @invisible: the invisible #hb_codepoint_t
  *
  * Sets the #hb_codepoint_t that replaces invisible characters in
@@ -1185,12 +1194,12 @@ hb_buffer_set_invisible_glyph (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_get_invisible_glyph:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * See hb_buffer_set_invisible_glyph().
  *
  * Return value:
- * The @buffer invisible #hb_codepoint_t.
+ * The @buffer invisible #hb_codepoint_t
  *
  * Since: 2.0.0
  **/
@@ -1203,7 +1212,7 @@ hb_buffer_get_invisible_glyph (hb_buffer_t    *buffer)
 
 /**
  * hb_buffer_reset:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Resets the buffer to its initial status, as if it was just newly created
  * with hb_buffer_create().
@@ -1218,7 +1227,7 @@ hb_buffer_reset (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_clear_contents:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Similar to hb_buffer_reset(), but does not clear the Unicode functions and
  * the replacement code point.
@@ -1233,13 +1242,13 @@ hb_buffer_clear_contents (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_pre_allocate:
- * @buffer: an #hb_buffer_t.
- * @size: number of items to pre allocate.
+ * @buffer: An #hb_buffer_t
+ * @size: Number of items to pre allocate.
  *
  * Pre allocates memory for @buffer to fit at least @size number of items.
  *
  * Return value:
- * %true if @buffer memory allocation succeeded, %false otherwise.
+ * %true if @buffer memory allocation succeeded, %false otherwise
  *
  * Since: 0.9.2
  **/
@@ -1251,7 +1260,7 @@ hb_buffer_pre_allocate (hb_buffer_t *buffer, unsigned int size)
 
 /**
  * hb_buffer_allocation_successful:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Check if allocating memory for the buffer succeeded.
  *
@@ -1268,9 +1277,9 @@ hb_buffer_allocation_successful (hb_buffer_t  *buffer)
 
 /**
  * hb_buffer_add:
- * @buffer: an #hb_buffer_t.
- * @codepoint: a Unicode code point.
- * @cluster: the cluster value of @codepoint.
+ * @buffer: An #hb_buffer_t
+ * @codepoint: A Unicode code point.
+ * @cluster: The cluster value of @codepoint.
  *
  * Appends a character with the Unicode value of @codepoint to @buffer, and
  * gives it the initial cluster value of @cluster. Clusters can be any thing
@@ -1294,8 +1303,8 @@ hb_buffer_add (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_set_length:
- * @buffer: an #hb_buffer_t.
- * @length: the new length of @buffer.
+ * @buffer: An #hb_buffer_t
+ * @length: The new length of @buffer
  *
  * Similar to hb_buffer_pre_allocate(), but clears any new items added at the
  * end.
@@ -1336,7 +1345,7 @@ hb_buffer_set_length (hb_buffer_t  *buffer,
 
 /**
  * hb_buffer_get_length:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Returns the number of items in the buffer.
  *
@@ -1354,8 +1363,8 @@ hb_buffer_get_length (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_get_glyph_infos:
- * @buffer: an #hb_buffer_t.
- * @length: (out): output array length.
+ * @buffer: An #hb_buffer_t
+ * @length: (out): The output-array length.
  *
  * Returns @buffer glyph information array.  Returned pointer
  * is valid as long as @buffer contents are not modified.
@@ -1378,8 +1387,8 @@ hb_buffer_get_glyph_infos (hb_buffer_t  *buffer,
 
 /**
  * hb_buffer_get_glyph_positions:
- * @buffer: an #hb_buffer_t.
- * @length: (out): output length.
+ * @buffer: An #hb_buffer_t
+ * @length: (out): The output length
  *
  * Returns @buffer glyph position array.  Returned pointer
  * is valid as long as @buffer contents are not modified.
@@ -1424,12 +1433,12 @@ hb_buffer_has_positions (hb_buffer_t  *buffer)
 
 /**
  * hb_glyph_info_get_glyph_flags:
- * @info: a #hb_glyph_info_t.
+ * @info: a #hb_glyph_info_t
  *
  * Returns glyph flags encoded within a #hb_glyph_info_t.
  *
  * Return value:
- * The #hb_glyph_flags_t encoded within @info.
+ * The #hb_glyph_flags_t encoded within @info
  *
  * Since: 1.5.0
  **/
@@ -1441,7 +1450,7 @@ hb_glyph_flags_t
 
 /**
  * hb_buffer_reverse:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Reverses buffer contents.
  *
@@ -1455,11 +1464,11 @@ hb_buffer_reverse (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_reverse_range:
- * @buffer: an #hb_buffer_t.
- * @start: start index.
- * @end: end index.
+ * @buffer: An #hb_buffer_t
+ * @start: start index
+ * @end: end index
  *
- * Reverses buffer contents between start to end.
+ * Reverses buffer contents between @start and @end.
  *
  * Since: 0.9.41
  **/
@@ -1472,7 +1481,7 @@ hb_buffer_reverse_range (hb_buffer_t *buffer,
 
 /**
  * hb_buffer_reverse_clusters:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Reverses buffer clusters.  That is, the buffer contents are
  * reversed, then each cluster (consecutive items having the
@@ -1488,7 +1497,7 @@ hb_buffer_reverse_clusters (hb_buffer_t *buffer)
 
 /**
  * hb_buffer_guess_segment_properties:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Sets unset buffer segment properties based on buffer Unicode
  * contents.  If buffer is not empty, it must have content type
@@ -1590,12 +1599,12 @@ hb_buffer_add_utf (hb_buffer_t  *buffer,
 
 /**
  * hb_buffer_add_utf8:
- * @buffer: an #hb_buffer_t.
- * @text: (array length=text_length) (element-type uint8_t): an array of UTF-8
+ * @buffer: An #hb_buffer_t
+ * @text: (array length=text_length) (element-type uint8_t): An array of UTF-8
  *               characters to append.
- * @text_length: the length of the @text, or -1 if it is %NULL terminated.
- * @item_offset: the offset of the first character to add to the @buffer.
- * @item_length: the number of characters to add to the @buffer, or -1 for the
+ * @text_length: The length of the @text, or -1 if it is %NULL terminated.
+ * @item_offset: The offset of the first character to add to the @buffer.
+ * @item_length: The number of characters to add to the @buffer, or -1 for the
  *               end of @text (assuming it is %NULL terminated).
  *
  * See hb_buffer_add_codepoints().
@@ -1617,12 +1626,12 @@ hb_buffer_add_utf8 (hb_buffer_t  *buffer,
 
 /**
  * hb_buffer_add_utf16:
- * @buffer: an #hb_buffer_t.
- * @text: (array length=text_length): an array of UTF-16 characters to append.
- * @text_length: the length of the @text, or -1 if it is %NULL terminated.
- * @item_offset: the offset of the first character to add to the @buffer.
- * @item_length: the number of characters to add to the @buffer, or -1 for the
- *               end of @text (assuming it is %NULL terminated).
+ * @buffer: An #hb_buffer_t
+ * @text: (array length=text_length): An array of UTF-16 characters to append
+ * @text_length: The length of the @text, or -1 if it is %NULL terminated
+ * @item_offset: The offset of the first character to add to the @buffer
+ * @item_length: The number of characters to add to the @buffer, or -1 for the
+ *               end of @text (assuming it is %NULL terminated)
  *
  * See hb_buffer_add_codepoints().
  *
@@ -1643,12 +1652,12 @@ hb_buffer_add_utf16 (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_add_utf32:
- * @buffer: an #hb_buffer_t.
- * @text: (array length=text_length): an array of UTF-32 characters to append.
- * @text_length: the length of the @text, or -1 if it is %NULL terminated.
- * @item_offset: the offset of the first character to add to the @buffer.
- * @item_length: the number of characters to add to the @buffer, or -1 for the
- *               end of @text (assuming it is %NULL terminated).
+ * @buffer: An #hb_buffer_t
+ * @text: (array length=text_length): An array of UTF-32 characters to append
+ * @text_length: The length of the @text, or -1 if it is %NULL terminated
+ * @item_offset: The offset of the first character to add to the @buffer
+ * @item_length: The number of characters to add to the @buffer, or -1 for the
+ *               end of @text (assuming it is %NULL terminated)
  *
  * See hb_buffer_add_codepoints().
  *
@@ -1669,13 +1678,13 @@ hb_buffer_add_utf32 (hb_buffer_t    *buffer,
 
 /**
  * hb_buffer_add_latin1:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  * @text: (array length=text_length) (element-type uint8_t): an array of UTF-8
- *               characters to append.
- * @text_length: the length of the @text, or -1 if it is %NULL terminated.
- * @item_offset: the offset of the first character to add to the @buffer.
+ *               characters to append
+ * @text_length: the length of the @text, or -1 if it is %NULL terminated
+ * @item_offset: the offset of the first character to add to the @buffer
  * @item_length: the number of characters to add to the @buffer, or -1 for the
- *               end of @text (assuming it is %NULL terminated).
+ *               end of @text (assuming it is %NULL terminated)
  *
  * Similar to hb_buffer_add_codepoints(), but allows only access to first 256
  * Unicode code points that can fit in 8-bit strings.
@@ -1731,8 +1740,8 @@ hb_buffer_add_codepoints (hb_buffer_t          *buffer,
 
 /**
  * hb_buffer_append:
- * @buffer: an #hb_buffer_t.
- * @source: source #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
+ * @source: source #hb_buffer_t
  * @start: start index into source buffer to copy.  Use 0 to copy from start of buffer.
  * @end: end index into source buffer to copy.  Use @HB_FEATURE_GLOBAL_END to copy to end of buffer.
  *
@@ -1838,7 +1847,7 @@ normalize_glyphs_cluster (hb_buffer_t *buffer,
 
 /**
  * hb_buffer_normalize_glyphs:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  *
  * Reorders a glyph buffer to have canonical in-cluster glyph order / position.
  * The resulting clusters should behave identical to pre-reordering clusters.
@@ -1984,7 +1993,7 @@ hb_buffer_diff (hb_buffer_t *buffer,
 #ifndef HB_NO_BUFFER_MESSAGE
 /**
  * hb_buffer_set_message_func:
- * @buffer: an #hb_buffer_t.
+ * @buffer: An #hb_buffer_t
  * @func: (closure user_data) (destroy destroy) (scope notified):
  * @user_data:
  * @destroy:

src/hb-buffer.h

@@ -314,6 +314,23 @@ hb_buffer_get_flags (hb_buffer_t *buffer);
  * @HB_BUFFER_CLUSTER_LEVEL_CHARACTERS: Don't group cluster values.
  * @HB_BUFFER_CLUSTER_LEVEL_DEFAULT: Default cluster level,
  *   equal to @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES.
+ * 
+ * Data type for holding HarfBuzz's clustering behavior options. The cluster level
+ * dictates one aspect of how HarfBuzz will treat non-base characters 
+ * during shaping.
+ *
+ * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES, non-base
+ * characters are merged into the cluster of the base character that precedes them.
+ *
+ * In @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS, non-base characters are initially
+ * assigned their own cluster values, which are not merged into preceding base
+ * clusters. This allows HarfBuzz to perform additional operations like reorder
+ * sequences of adjacent marks.
+ *
+ * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_GRAPHEMES is the default, because it maintains
+ * backward compatibility with older versions of HarfBuzz. New client programs that
+ * do not need to maintain such backward compatibility are recommended to use
+ * @HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS instead of the default.
  *
  * Since: 0.9.42
  */