[docs] A bit more buffers documentation
diff --git a/src/hb-buffer.h b/src/hb-buffer.h
index e24ffa4..9b72383 100644
--- a/src/hb-buffer.h
+++ b/src/hb-buffer.h
@@ -40,7 +40,28 @@
HB_BEGIN_DECLS
-
+/**
+ * hb_glyph_info_t:
+ * @codepoint: either a Unicode code point (before shaping) or a glyph index
+ * (after shaping).
+ * @mask:
+ * @cluster: the index of the character in the original text that corresponds
+ * to this #hb_glyph_info_t, or whatever the client passes to
+ * hb_buffer_add(). More than one #hb_glyph_info_t can have the same
+ * @cluster value, if they resulted from the same character (e.g. one
+ * to many glyph substitution), and when more than one character gets
+ * merged in the same glyph (e.g. many to one glyph substitution) the
+ * #hb_glyph_info_t will have cluster value corresponding to the
+ * first of them. By default some characters are merged into the same
+ * cluster (e.g. combining marks have the same cluster as their
+ * bases) even if they are separate glyphs,
+ * hb_buffer_set_cluster_level() allow selecting more fine-grained
+ * cluster handling.
+ *
+ * The #hb_glyph_info_t is the structure that holds informations about the
+ * glyphs and their relation to input text.
+ *
+ */
typedef struct hb_glyph_info_t {
hb_codepoint_t codepoint;
hb_mask_t mask;
@@ -51,6 +72,22 @@
hb_var_int_t var2;
} hb_glyph_info_t;
+/**
+ * hb_glyph_position_t:
+ * @x_advance: how much the line advances after drawing this glyph when setting
+ * text in horizontal direction.
+ * @y_advance: how much the line advances after drawing this glyph when setting
+ * text in vertical direction.
+ * @x_offset: how much the glyph moves on the X-axis before drawing it, this
+ * should not affect how much the line advances.
+ * @y_offset: how much the glyph moves on the Y-axis before drawing it, this
+ * should not affect how much the line advances.
+ *
+ * The #hb_glyph_position_t is the structure that holds the positions of the
+ * glyph in both horizontal and vertical directions. All positions in
+ * #hb_glyph_position_t are relative to the current point.
+ *
+ */
typedef struct hb_glyph_position_t {
hb_position_t x_advance;
hb_position_t y_advance;
@@ -176,7 +213,22 @@
hb_buffer_guess_segment_properties (hb_buffer_t *buffer);
-/*
+/**
+ * hb_buffer_flags_t:
+ * @HB_BUFFER_FLAG_DEFAULT: the default buffer flag.
+ * @HB_BUFFER_FLAG_BOT: flag indicating that special handling of the beginning
+ * of text can be applied to this buffer. Should usually
+ * be set unless you are passing to the buffer only part
+ * of the text without the full context.
+ * @HB_BUFFER_FLAG_EOT: flag indicating that special handling of the end of text
+ * can be applied to this buffer, similar to
+ * @HB_BUFFER_FLAG_EOT.
+ * @HB_BUFFER_FLAG_PRESERVE_DEFAULT_IGNORABLES:
+ * flag indication that character with Default Ignorable
+ * Unicode property should use the corresponding glyph
+ * from the font, instead of replacing them with the space
+ * glyph and zeroing the advance width.
+ *
* Since: 0.9.20
*/
typedef enum { /*< flags >*/
