Lisp_Object font_height;
/* Object and position where the current display element came from.
- Object can be a Lisp string in case the current display element
- comes from an overlay string, or it is buffer. It may also be nil
- during mode-line update. Position is a position in object. */
+ Object is normally the buffer which is being rendered, but it can
+ also be a Lisp string in case the current display element comes
+ from an overlay string or from a display string (before- or
+ after-string). It may also be nil when a C string is being
+ rendered, e.g., during mode-line or header-line update. It can
+ also be a cons cell of the form `(space ...)', when we produce a
+ stretch glyph from a `display' specification. Finally, it can be
+ a zero-valued Lisp integer, but only temporarily, when we are
+ producing special glyphs for display purposes, like truncation
+ and continuation glyphs, or blanks that extend each line to the
+ edge of the window on a TTY.
+
+ Position is the current iterator position in object. */
Lisp_Object object;
struct text_pos position;