[pango/ligature-caret-rtl-fixes: 4/4] docs: Some detail for PangoGlyphGeometry

[Matthias Clasen <matthiasc src gnome org>]

commit 9979612c72ebee4674bfd99eaabb373034b5efe4
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Aug 27 11:25:49 2021 -0400

    docs: Some detail for PangoGlyphGeometry

 pango/pango-glyph.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)
---
diff --git a/pango/pango-glyph.h b/pango/pango-glyph.h
index 4dc77fd1..2094fa53 100644
--- a/pango/pango-glyph.h
+++ b/pango/pango-glyph.h
@@ -58,6 +58,19 @@ typedef gint32 PangoGlyphUnit;
  *
  * The `PangoGlyphGeometry` structure contains width and positioning
  * information for a single glyph.
+ *
+ * Note that @width is not guaranteed to be the same as the glyph
+ * extents. Kerning and other positioning applied during shaping will
+ * affect both the @width and the @x_offset for the glyphs in the
+ * glyph string that results from shaping.
+ *
+ * The information in this struct is intended for rendering the glyphs,
+ * as follows:
+ *
+ * 1. Render the current glyph at (x + x_offset, y + y_offset),
+ *    where (x, y) is the current point
+ * 2. Advance the current point to (x + xoffset, y)
+ * 3. Render the next glyph...
  */
 struct _PangoGlyphGeometry
 {