Is there a way to get what-cursor-position show composition?

On Tue, May 11, 2010 at 3:20 PM, Kenichi Handa <handa@m17n.org> wrote:
> Could you please check the rendering (position of
> diacriticals, etc.)?

I see some problems, some not present in your image see my example attached:
In the phrase:
שָׁלוֹם לְמִשְׁתַּמְּשֵׁי אִמַאקְס
The Holam point above Vav is not centred above the letter.
The Dagesh points in the Tav and Mem letters is not centred but too
close to the left side of the letter.

In the phrase:
A "אֲעוֹלֵל 123 כַּגֶּפֶן" B.
The point Hataf-Patah under the letter Alef is not centred, but is
placed slightly to left than where it should. This also visible in
your sample.

The last word:
עַשֶּׁשֶׁת
The Dagesh point on the first (right) Shin is not visible at all.
(e.g. http://he.wiktionary.org/wiki/%D7%A2%D7%A9%D7%A9%D7%AA)

The font used is xft:-unknown-DejaVu
Sans-normal-normal-normal-*-27-*-*-*-*-0-iso10646-1
Font version 2.29

When these sample are rendered correctly you might want to try more
complex such as http://www.mechon-mamre.org/c/ct/c2831.htm V12 has a
challenging example.

I now use a refined composition regexp:
(defconst hebrew-composable-pattern
  (concat
   "\\("
   "[\u05D6-\u05D9\u05DC-\u05E2\u05E5-\u05E8]" ;; base
   "\u05BC?"                        ;; 0-1 marks of 1st class (dagesh)
   "[\u05B0-\u05B9\u05BB\u05C7]?"   ;; 0-1 marks of 3rd class (niqqud)
   "[\u0591-\u05AF\u05BD]*"         ;; 0-2 (possibly 3) marks of 4th class
   "\\|"
   "[\u05D0-\u05D4\u05DA\u05DB\u05E4\u05E5-\u05EA]"
                                    ;; base (allows rafe)
   "[\u05BC\u05BF]?"                ;; 0-1 marks of 1st class (dagesh/rafe)
   "[\u05B0-\u05B9\u05BB\u05C7]?"   ;; 0-1 marks of 3rd class (niqqud)
   "[\u0591-\u05AF\u05BD]*"         ;; 0-2 (possibly 3) marks of 4th class
   "\\|"
   "\u05D5"                         ;; base (vav)
   "\u05BC?"                        ;; 0-1 marks of 1st class (dagesh)
   "[\u05B0-\u05BB\u05C7]?"         ;; 0-1 marks of extended 3rd class (niqqud)
   "[\u0591-\u05AF\u05BD]*"         ;; 0-2 (possibly 3) marks of 4th class
   "\\|"
   "\u05E9"                         ;; base (shin)
   "\u05BC?"                        ;; 0-1 marks of 1st class (dagesh)
   "[\u05C1\u05C2]?"                ;; 0-1 marks of 2nd class (shin dot)
   "[\u05B0-\u05B9\u05BB\u05C7]?"   ;; 0-1 marks of 3rd class (niqqud)
   "[\u0591-\u05AF\u05BD]*"         ;; 0-2 (possibly 3) marks of 4th class
   "\\|"
   "[\u05F1-\u05F3]"                ;; base (yidish ligatures)
   "[\u05B0-\u05B9\u05BB\u05C7]?"   ;; 0-1 marks of 3rd class (niqqud)
   "[\u0591-\u05AF\u05BD]*"         ;; 0-2 (possibly 3) marks of 4th class
   "\\)")
  "Regexp matching a composable sequence of Hebrew characters.")
(set-char-table-range
 composition-function-table '(#x591 . #x5F4)
 (list (vector hebrew-composable-pattern 0 'font-shape-gstring)))