[Emacs-diffs] emacs/lisp composite.el

[Kenichi Handa]

CVSROOT:        /cvsroot/emacs
Module name:    emacs
Changes by:     Kenichi Handa <handa>   09/06/16 00:33:18

Modified files:
        lisp           : composite.el 

Log message:
        (compose-region): Improve the docstring.

CVSWeb URLs:
http://cvs.savannah.gnu.org/viewcvs/emacs/lisp/composite.el?cvsroot=emacs&r1=1.47&r2=1.48

Patches:
Index: composite.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/composite.el,v
retrieving revision 1.47
retrieving revision 1.48
diff -u -b -r1.47 -r1.48
--- composite.el        10 Jun 2009 00:34:19 -0000      1.47
+++ composite.el        16 Jun 2009 00:33:18 -0000      1.48
@@ -185,8 +185,17 @@
 (defun compose-region (start end &optional components modification-func)
   "Compose characters in the current region.
 
-Characters are composed relatively, i.e. composed by overstricking or
-stacking depending on ascent, descent and other properties.
+Characters are composed relatively, i.e. composed by overstriking
+or stacking depending on ascent, descent and other metrics of
+glyphs.
+
+For instance, if the region has three characters \"XYZ\", X is
+regarded as BASE glyph, and Y is displayed:
+  (1) above BASE if Y's descent value is not positive
+  (2) below BASE if Y's ascent value is not positive
+  (3) on BASE (i.e. at the BASE position) otherwise
+and Z is displayed with the same rule while regarding the whole
+XY glyphs as BASE.
 
 When called from a program, expects these four arguments.