Re: speed of testtext, directionality

[Owen Taylor <otaylor redhat com>]

Karl Koehler <koehler@or.uni-bonn.de> writes:

> On 10 Jul 2000, Owen Taylor wrote:
> 
> > > #2: Strange behaviour of the arabic shaper when appending text to the end 
> > > ot the line in left-to-right mode:
> > > Actually, in this case, no shaping is done, and the characters do not 
> > > appear ( Or only unshaped, if you have iso10646-1 encoded fonts ).
> > > In this case, even though several arabic letters may have been typed,
> > > any shaper's PangoAnalysis reveals that we are in a left-to-right run
> > > of characters : analysis->level % 2 == 0 ! 
> [ ... Ø]
> > Hmmm - I can't seem to reproduce this. If I create an empty
> > buffer in texttext, in LTR mode, and start typing in arabic
> > characters, they are shaped as I would expect.
> 
> Actually, for me this is a sure  way to have them not shaped. 

OK, tracked this one down. (I'm not sure why I didn't see it 
happening before - since an example was staring me in the face for
pango-viewer HELLO.utf8)

Here is a patch for fribidi-0.1.12 that fixes the problem - I'm
not sure that it is the most elegant way of fixing the problem
but it seems to work.

Regards,
                                        Owen

--- fribidi-0.1.12/fribidi.c.rtl	Wed Jul 19 17:08:33 2000
+++ fribidi-0.1.12/fribidi.c	Wed Jul 19 17:12:12 2000
@@ -499,6 +499,15 @@
 	RL_TYPE(pp->prev) = FRIBIDI_TYPE_L;
     }
 
+  /* Handle the two rules that effect pp->prev for the last element */
+
+  if (RL_TYPE (pp->prev) == FRIBIDI_TYPE_AL) /* W3 */
+    RL_TYPE(pp->prev) = FRIBIDI_TYPE_R;
+  if (RL_TYPE (pp->prev) == FRIBIDI_TYPE_EN  /* W7 */
+      && last_strong == FRIBIDI_TYPE_L)	     
+    RL_TYPE(pp->prev) = FRIBIDI_TYPE_L;
+  
+
   compact_list(type_rl_list);
   
   /* 5. Resolving Neutral Types */