FS#10720 - Support for displaying diacritic characters

This commit corrects the display of diacritic characters, which exist in many
languages. Hopefully, it will make Rockbox much more usable for users of these
languages.

Diacritic information (which used to decide whether a given character is
diacritic or not) is taken from the Unicode Standard, Version 5.2.

This feature does not affect drawing performance much, as the diacritic
database is cached (simple MRU mechanism).

There may be room for further performance, footprint, and
code-reuse wise improvements, that could be worked on in the future.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@23742 a1c6a512-1295-4272-9138-f99709370657

5 files changed, 494 insertions, 11 deletions

diff --git a/firmware/SOURCES b/firmware/SOURCES
index 18106df2cf..5221d3fb8d 100644
--- a/firmware/SOURCES
+++ b/firmware/SOURCES
@@ -95,6 +95,7 @@ drivers/lcd-16bit-vert.c
 drivers/lcd-16bit.c
 #endif
 #endif /* LCD_DEPTH */
+drivers/diacritic.c
 #endif /* HAVE_LCD_BITMAP */
 
 #ifdef HAVE_REMOTE_LCD
diff --git a/firmware/drivers/diacritic.c b/firmware/drivers/diacritic.c
new file mode 100644
index 0000000000..5074beb2ad
--- /dev/null
+++ b/firmware/drivers/diacritic.c
@@ -0,0 +1,378 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 Phinitnun Chanasabaeng
+ *     Initial work
+ * Copyright (C) 2009 Tomer Shalev
+ *
+ * Rockbox diacritic positioning
+ * Based on initial work by Phinitnun Chanasabaeng
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "diacritic.h"
+#include "system.h"
+
+#define DIAC_FLAG_DIACRITIC (1 << 31)
+#define DIAC_FLAG_RTL       (1 << 30)
+#define DIAC_MASK           0x000FFFFF
+
+#define DIAC_VAL(i)          (diac_range[(i)] & DIAC_MASK)
+#define DIAC_IS_DIACRITIC(i) ((diac_range[(i)] & DIAC_FLAG_DIACRITIC) ? 1 : 0)
+#define DIAC_IS_RTL(i)       ((diac_range[(i)] & DIAC_FLAG_RTL) ? 1 : 0)
+#define DIAC_NUM_RANGES      (ARRAYLEN(diac_range))
+
+/* Sorted by Unicode value */
+static const int diac_range[] =
+{
+    0x00000,
+    0x002ff,
+    0x0036f | DIAC_FLAG_DIACRITIC, /* Combining Diacritical Marks */
+    0x00482,
+    0x00489 | DIAC_FLAG_DIACRITIC, /* Cyrillic */
+    0x00590,
+    0x005bd | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Hebrew */
+    0x005be | DIAC_FLAG_RTL,
+    0x005bf | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Hebrew */
+    0x005c0 | DIAC_FLAG_RTL,
+    0x005c2 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Hebrew */
+    0x005c3 | DIAC_FLAG_RTL,
+    0x005c5 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Hebrew */
+    0x005c6 | DIAC_FLAG_RTL,
+    0x005c7 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Hebrew */
+    0x0060f | DIAC_FLAG_RTL,
+    0x0061a | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x0064a | DIAC_FLAG_RTL,
+    0x0065e | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x0066f | DIAC_FLAG_RTL,
+    0x00670 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x006d5 | DIAC_FLAG_RTL,
+    0x006dc | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x006de | DIAC_FLAG_RTL,
+    0x006e4 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x006e6 | DIAC_FLAG_RTL,
+    0x006e8 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x006e9 | DIAC_FLAG_RTL,
+    0x006ed | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Arabic */
+    0x00710 | DIAC_FLAG_RTL,
+    0x00711 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Syriac */
+    0x0072f | DIAC_FLAG_RTL,
+    0x0074a | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Syriac */
+    0x007a5 | DIAC_FLAG_RTL,
+    0x007b0 | DIAC_FLAG_DIACRITIC | DIAC_FLAG_RTL, /* Thaana */
+    0x007c0 | DIAC_FLAG_RTL,
+    0x007ea,
+    0x007f3 | DIAC_FLAG_DIACRITIC, /* NKo */
+    0x00815,
+    0x00819 | DIAC_FLAG_DIACRITIC, /* Samaritan */
+    0x0081a,
+    0x00823 | DIAC_FLAG_DIACRITIC, /* Samaritan */
+    0x00824,
+    0x00827 | DIAC_FLAG_DIACRITIC, /* Samaritan */
+    0x00828,
+    0x0082d | DIAC_FLAG_DIACRITIC, /* Samaritan */
+    0x008ff,
+    0x00903 | DIAC_FLAG_DIACRITIC, /* Devanagari */
+    0x0093b,
+    0x0093c | DIAC_FLAG_DIACRITIC, /* Devanagari */
+    0x0093d,
+    0x0094e | DIAC_FLAG_DIACRITIC, /* Devanagari */
+    0x00950,
+    0x00955 | DIAC_FLAG_DIACRITIC, /* Devanagari */
+    0x00961,
+    0x00963 | DIAC_FLAG_DIACRITIC, /* Devanagari */
+    0x00980,
+    0x00983 | DIAC_FLAG_DIACRITIC, /* Bengali */
+    0x009bb,
+    0x009bc | DIAC_FLAG_DIACRITIC, /* Bengali */
+    0x009bd,
+    0x009cd | DIAC_FLAG_DIACRITIC, /* Bengali */
+    0x009d6,
+    0x009d7 | DIAC_FLAG_DIACRITIC, /* Bengali */
+    0x009e1,
+    0x009e3 | DIAC_FLAG_DIACRITIC, /* Bengali */
+    0x00a00,
+    0x00a03 | DIAC_FLAG_DIACRITIC, /* Gurmukhi */
+    0x00a3b,
+    0x00a51 | DIAC_FLAG_DIACRITIC, /* Gurmukhi */
+    0x00a6f,
+    0x00a71 | DIAC_FLAG_DIACRITIC, /* Gurmukhi */
+    0x00a74,
+    0x00a75 | DIAC_FLAG_DIACRITIC, /* Gurmukhi */
+    0x00a80,
+    0x00a83 | DIAC_FLAG_DIACRITIC, /* Gujarati */
+    0x00abb,
+    0x00abc | DIAC_FLAG_DIACRITIC, /* Gujarati */
+    0x00abd,
+    0x00acd | DIAC_FLAG_DIACRITIC, /* Gujarati */
+    0x00ae1,
+    0x00ae3 | DIAC_FLAG_DIACRITIC, /* Gujarati */
+    0x00b00,
+    0x00b03 | DIAC_FLAG_DIACRITIC, /* Oriya */
+    0x00b3b,
+    0x00b3c | DIAC_FLAG_DIACRITIC, /* Oriya */
+    0x00b3d,
+    0x00b57 | DIAC_FLAG_DIACRITIC, /* Oriya */
+    0x00b81,
+    0x00b82 | DIAC_FLAG_DIACRITIC, /* Tamil */
+    0x00bbd,
+    0x00bcd | DIAC_FLAG_DIACRITIC, /* Tamil */
+    0x00bd6,
+    0x00bd7 | DIAC_FLAG_DIACRITIC, /* Tamil */
+    0x00c00,
+    0x00c03 | DIAC_FLAG_DIACRITIC, /* Telugu */
+    0x00c3d,
+    0x00c56 | DIAC_FLAG_DIACRITIC, /* Telugu */
+    0x00c61,
+    0x00c63 | DIAC_FLAG_DIACRITIC, /* Telugu */
+    0x00c81,
+    0x00c83 | DIAC_FLAG_DIACRITIC, /* Kannada */
+    0x00cbb,
+    0x00cbc | DIAC_FLAG_DIACRITIC, /* Kannada */
+    0x00cbd,
+    0x00cd6 | DIAC_FLAG_DIACRITIC, /* Kannada */
+    0x00ce1,
+    0x00ce3 | DIAC_FLAG_DIACRITIC, /* Kannada */
+    0x00d01,
+    0x00d03 | DIAC_FLAG_DIACRITIC, /* Malayalam */
+    0x00d3d,
+    0x00d57 | DIAC_FLAG_DIACRITIC, /* Malayalam */
+    0x00d61,
+    0x00d63 | DIAC_FLAG_DIACRITIC, /* Malayalam */
+    0x00d81,
+    0x00d83 | DIAC_FLAG_DIACRITIC, /* Sinhala */
+    0x00dc9,
+    0x00df3 | DIAC_FLAG_DIACRITIC, /* Sinhala */
+    0x00e30,
+    0x00e31 | DIAC_FLAG_DIACRITIC, /* Thai */
+    0x00e33,
+    0x00e3a | DIAC_FLAG_DIACRITIC, /* Thai */
+    0x00e46,
+    0x00e4e | DIAC_FLAG_DIACRITIC, /* Thai */
+    0x00eb0,
+    0x00eb1 | DIAC_FLAG_DIACRITIC, /* Lao */
+    0x00eb3,
+    0x00ebc | DIAC_FLAG_DIACRITIC, /* Lao */
+    0x00ec7,
+    0x00ecd | DIAC_FLAG_DIACRITIC, /* Lao */
+    0x00f17,
+    0x00f19 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f34,
+    0x00f35 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f36,
+    0x00f37 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f38,
+    0x00f39 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f3d,
+    0x00f3f | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f70,
+    0x00f84 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f85,
+    0x00f87 | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x00f8f,
+    0x00fbc | DIAC_FLAG_DIACRITIC, /* Tibetan */
+    0x0102a,
+    0x0103e | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01055,
+    0x01059 | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x0105d,
+    0x01060 | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01061,
+    0x01064 | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01066,
+    0x0106d | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01070,
+    0x01074 | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01081,
+    0x0108d | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x0108e,
+    0x0108f | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x01099,
+    0x0109d | DIAC_FLAG_DIACRITIC, /* Myanmar */
+    0x0135e,
+    0x0135f | DIAC_FLAG_DIACRITIC, /* Ethiopic */
+    0x01711,
+    0x01714 | DIAC_FLAG_DIACRITIC, /* Tagalog */
+    0x01731,
+    0x01734 | DIAC_FLAG_DIACRITIC, /* Hanunoo */
+    0x01751,
+    0x01753 | DIAC_FLAG_DIACRITIC, /* Buhid */
+    0x01771,
+    0x01773 | DIAC_FLAG_DIACRITIC, /* Tagbanwa */
+    0x017b5,
+    0x017d3 | DIAC_FLAG_DIACRITIC, /* Khmer */
+    0x017dc,
+    0x017dd | DIAC_FLAG_DIACRITIC, /* Khmer */
+    0x018a8,
+    0x018a9 | DIAC_FLAG_DIACRITIC, /* Mongolian */
+    0x0191f,
+    0x0193b | DIAC_FLAG_DIACRITIC, /* Limbu */
+    0x019af,
+    0x019c0 | DIAC_FLAG_DIACRITIC, /* New Tai Lue */
+    0x019c7,
+    0x019c9 | DIAC_FLAG_DIACRITIC, /* New Tai Lue */
+    0x01a16,
+    0x01a1b | DIAC_FLAG_DIACRITIC, /* Buginese */
+    0x01a54,
+    0x01a7f | DIAC_FLAG_DIACRITIC, /* Tai Tham */
+    0x01aff,
+    0x01b04 | DIAC_FLAG_DIACRITIC, /* Balinese */
+    0x01b33,
+    0x01b44 | DIAC_FLAG_DIACRITIC, /* Balinese */
+    0x01b6a,
+    0x01b73 | DIAC_FLAG_DIACRITIC, /* Balinese */
+    0x01b7f,
+    0x01b82 | DIAC_FLAG_DIACRITIC, /* Sundanese */
+    0x01ba0,
+    0x01baa | DIAC_FLAG_DIACRITIC, /* Sundanese */
+    0x01c23,
+    0x01c37 | DIAC_FLAG_DIACRITIC, /* Lepcha */
+    0x01ccf,
+    0x01cd2 | DIAC_FLAG_DIACRITIC, /* Vedic Extensions */
+    0x01cd3,
+    0x01ce8 | DIAC_FLAG_DIACRITIC, /* Vedic Extensions */
+    0x01cec,
+    0x01ced | DIAC_FLAG_DIACRITIC, /* Vedic Extensions */
+    0x01cf1,
+    0x01cf2 | DIAC_FLAG_DIACRITIC, /* Vedic Extensions */
+    0x01dbf,
+    0x01dff | DIAC_FLAG_DIACRITIC, /* Combining Diacritical Marks Supplement */
+    0x020cf,
+    0x020f0 | DIAC_FLAG_DIACRITIC, /* Combining Diacritical Marks for Symbols */
+    0x02cee,
+    0x02cf1 | DIAC_FLAG_DIACRITIC, /* Coptic */
+    0x02ddf,
+    0x02dff | DIAC_FLAG_DIACRITIC, /* Coptic */
+    0x03029,
+    0x0302f | DIAC_FLAG_DIACRITIC, /* CJK Symbols and Punctuation */
+    0x03098,
+    0x0309a | DIAC_FLAG_DIACRITIC, /* Hiragana */
+    0x0a66e,
+    0x0a672 | DIAC_FLAG_DIACRITIC, /* Hiragana */
+    0x0a67b,
+    0x0a67d | DIAC_FLAG_DIACRITIC, /* Hiragana */
+    0x0a6ef,
+    0x0a6f1 | DIAC_FLAG_DIACRITIC, /* Bamum */
+    0x0a801,
+    0x0a802 | DIAC_FLAG_DIACRITIC, /* Syloti Nagri */
+    0x0a805,
+    0x0a806 | DIAC_FLAG_DIACRITIC, /* Syloti Nagri */
+    0x0a80a,
+    0x0a80b | DIAC_FLAG_DIACRITIC, /* Syloti Nagri */
+    0x0a822,
+    0x0a827 | DIAC_FLAG_DIACRITIC, /* Syloti Nagri */
+    0x0a87f,
+    0x0a881 | DIAC_FLAG_DIACRITIC, /* Saurashtra */
+    0x0a8b3,
+    0x0a8c4 | DIAC_FLAG_DIACRITIC, /* Saurashtra */
+    0x0a8df,
+    0x0a8f1 | DIAC_FLAG_DIACRITIC, /* Devanagari Extended */
+    0x0a925,
+    0x0a92d | DIAC_FLAG_DIACRITIC, /* Kayah Li */
+    0x0a946,
+    0x0a953 | DIAC_FLAG_DIACRITIC, /* Rejang */
+    0x0a97f,
+    0x0a983 | DIAC_FLAG_DIACRITIC, /* Javanese */
+    0x0a9b2,
+    0x0a9c0 | DIAC_FLAG_DIACRITIC, /* Javanese */
+    0x0aa28,
+    0x0aa36 | DIAC_FLAG_DIACRITIC, /* Cham */
+    0x0aa42,
+    0x0aa43 | DIAC_FLAG_DIACRITIC, /* Cham */
+    0x0aa4b,
+    0x0aa4d | DIAC_FLAG_DIACRITIC, /* Cham */
+    0x0aa7a,
+    0x0aa7b | DIAC_FLAG_DIACRITIC, /* Cham */
+    0x0aaaf,
+    0x0aab0 | DIAC_FLAG_DIACRITIC, /* Tai Viet */
+    0x0aab1,
+    0x0aab4 | DIAC_FLAG_DIACRITIC, /* Tai Viet */
+    0x0aab6,
+    0x0aab8 | DIAC_FLAG_DIACRITIC, /* Tai Viet */
+    0x0aabd,
+    0x0aabf | DIAC_FLAG_DIACRITIC, /* Tai Viet */
+    0x0aac0,
+    0x0aac1 | DIAC_FLAG_DIACRITIC, /* Tai Viet */
+    0x0abe2,
+    0x0abea | DIAC_FLAG_DIACRITIC, /* Meetei Mayek */
+    0x0abeb,
+    0x0abed | DIAC_FLAG_DIACRITIC, /* Meetei Mayek */
+    0x0fb1d,
+    0x0fb1e | DIAC_FLAG_DIACRITIC, /* Alphabetic Presentation Forms */
+    0x0fe1f,
+    0x0fe26 | DIAC_FLAG_DIACRITIC, /* Combining Half Marks */
+    0x1107f,
+    0x11082 | DIAC_FLAG_DIACRITIC, /* Kaithi */
+    0x110af,
+    0x110ba | DIAC_FLAG_DIACRITIC, /* Kaithi */
+    0x1d164,
+    0x1d169 | DIAC_FLAG_DIACRITIC, /* Musical Symbols */
+    0x1d16c,
+    0x1d182 | DIAC_FLAG_DIACRITIC, /* Musical Symbols */
+    0x1d184,
+    0x1d18b | DIAC_FLAG_DIACRITIC, /* Musical Symbols */
+    0x1d1a9,
+    0x1d1ad | DIAC_FLAG_DIACRITIC, /* Musical Symbols */
+    0x1d241,
+    0x1d244 | DIAC_FLAG_DIACRITIC, /* Ancient Greek Musical Notation */
+    0xe01ef,
+};
+
+#define MRU_MAX_LEN 32
+
+static unsigned short mru_len = 0;
+static unsigned short diacritic_mru[MRU_MAX_LEN];
+
+int is_diacritic(unsigned short char_code, bool *is_rtl)
+{
+    unsigned short mru, i;
+
+    /* Search in MRU */
+    for (mru = 0; mru < mru_len; mru++)
+    {
+        i = diacritic_mru[mru];
+
+        /* Found in MRU */
+        if (DIAC_VAL(i - 1) < char_code && char_code <= DIAC_VAL(i))
+            goto Found;
+    }
+
+    /* Search in DB */
+    for (i = 1; i < DIAC_NUM_RANGES; i++)
+    {
+        /* Found */
+        if (char_code < DIAC_VAL(i))
+            break;
+    }
+
+    /* Add MRU entry, or overwrite LRU if MRU array is full */
+    if (mru_len < MRU_MAX_LEN)
+        mru_len++;
+    else
+        mru--;
+
+Found:
+    /* Promote MRU item to top of MRU */
+    for ( ; mru > 0; mru--)
+        diacritic_mru[mru] = diacritic_mru[mru - 1];
+    diacritic_mru[0] = i;
+
+    /* Update RTL */
+    if (is_rtl)
+        *is_rtl = DIAC_IS_RTL(i);
+
+    return DIAC_IS_DIACRITIC(i);
+}
diff --git a/firmware/drivers/lcd-bitmap-common.c b/firmware/drivers/lcd-bitmap-common.c
index 70ae00ba84..5b79879d70 100644
--- a/firmware/drivers/lcd-bitmap-common.c
+++ b/firmware/drivers/lcd-bitmap-common.c
@@ -29,6 +29,7 @@
  ****************************************************************************/
 #include "stdarg.h"
 #include "sprintf.h"
+#include "diacritic.h"
 
 #ifndef LCDFN /* Not compiling for remote - define macros for main LCD. */
 #define LCDFN(fn) lcd_ ## fn
@@ -79,15 +80,22 @@ static void lcd_gradient_rect(int x1, int x2, int y, unsigned h,
 }
 #endif
 
+struct lcd_bitmap_char
+{
+    bool is_rtl;
+    bool is_diacritic;
+    int width;
+    int base_width;
+};
+
 /* put a string at a given pixel position, skipping first ofs pixel columns */
 static void LCDFN(putsxyofs)(int x, int y, int ofs, const unsigned char *str)
 {
-    unsigned short ch;
     unsigned short *ucs;
     struct font* pf = font_get(current_vp->font);
     int vp_flags = current_vp->flags;
-
-    ucs = bidi_l2v(str, 1);
+    int i, len;
+    static struct lcd_bitmap_char chars[SCROLL_LINE_SIZE];
 
     if ((vp_flags & VP_FLAG_ALIGNMENT_MASK) != 0)
     {
@@ -109,13 +117,59 @@ static void LCDFN(putsxyofs)(int x, int y, int ofs, const unsigned char *str)
         }
     }
 
-    while ((ch = *ucs++) != 0 && x < current_vp->width)
+    ucs = bidi_l2v(str, 1);
+    /* Mark diacritic and rtl flags for each character */
+    for (i = 0; i < SCROLL_LINE_SIZE && ucs[i]; i++)
+        chars[i].is_diacritic = is_diacritic(ucs[i], &chars[i].is_rtl);
+    len = i;
+
+    /* Get proportional width and glyph bits */
+    for (i = 0; i < len; i++)
+        chars[i].width = font_get_width(pf, ucs[i]);
+
+    /* Calculate base width for each character */
+    for (i = 0; i < len; i++)
+    {
+        if (chars[i].is_rtl)
+        {
+            /* Forward-seek the next non-diacritic character for base width */
+            if (chars[i].is_diacritic)
+            {
+                int j;
+
+                /* Jump to next non-diacritic character, and calc its width */
+                for (j = i; j < len && chars[j].is_diacritic; j++);
+
+                /* Set all related diacritic char's base-width accordingly */
+                for (; i <= j; i++)
+                    chars[i].base_width = chars[j].width;
+            }
+            else
+            {
+                chars[i].base_width = chars[i].width;
+            }
+        }
+        else
+        {
+            static int last_non_diacritic_width = 0;
+
+            if (!chars[i].is_diacritic)
+                last_non_diacritic_width = chars[i].width;
+
+            chars[i].base_width = last_non_diacritic_width;
+        }
+    }
+
+    for (i = 0; i < len; i++)
     {
-        int width;
         const unsigned char *bits;
+        unsigned short ch = ucs[i];
+        int width = chars[i].width;
+        int drawmode = 0, base_ofs = 0;
+        bool next_is_diacritic;
 
-        /* get proportional width and glyph bits */
-        width = font_get_width(pf, ch);
+        if (x >= current_vp->width)
+            break;
 
         if (ofs > width)
         {
@@ -123,13 +177,34 @@ static void LCDFN(putsxyofs)(int x, int y, int ofs, const unsigned char *str)
             continue;
         }
 
+        if (chars[i].is_diacritic)
+        {
+            drawmode = current_vp->drawmode;
+            current_vp->drawmode = DRMODE_FG;
+
+            base_ofs = (chars[i].base_width - width) / 2;
+        }
+
         bits = font_get_bits(pf, ch);
+        LCDFN(mono_bitmap_part)(bits, ofs, 0, width,
+            x + base_ofs, y, width - ofs, pf->height);
+
+        if (chars[i].is_diacritic)
+        {
+            current_vp->drawmode = drawmode;
+        }
 
-        LCDFN(mono_bitmap_part)(bits, ofs, 0, width, x, y, width - ofs,
-                                pf->height);
+        /* Increment if next char is not diacritic (non-rtl),
+         * or current char is non-diacritic and next char is diacritic (rtl)*/
+        next_is_diacritic = (ucs[i + 1] && chars[i + 1].is_diacritic);
 
-        x += width - ofs;
-        ofs = 0;
+        if (ucs[i + 1] &&
+            ((chars[i].is_rtl && !chars[i].is_diacritic) ||
+            (!chars[i].is_rtl && (chars[i + 1].is_rtl || !chars[i + 1].is_diacritic))))
+        {
+            x += chars[i].base_width - ofs;
+            ofs = 0;
+        }
     }
 }
 /* put a string at a given pixel position */
diff --git a/firmware/font.c b/firmware/font.c
index e02f276efe..624e0de9a7 100644
--- a/firmware/font.c
+++ b/firmware/font.c
@@ -35,6 +35,7 @@
 #include "debug.h"
 #include "panic.h"
 #include "rbunicode.h"
+#include "diacritic.h"
 
 #ifndef BOOTLOADER
 /* Font cache includes */
@@ -604,6 +605,8 @@ int font_getstringsize(const unsigned char *str, int *w, int *h, int fontnumber)
 
     for (str = utf8decode(str, &ch); ch != 0 ; str = utf8decode(str, &ch))
     {
+        if (is_diacritic(ch, NULL))
+            continue;
 
         /* get proportional width and glyph bits*/
         width += font_get_width(pf,ch);
diff --git a/firmware/include/diacritic.h b/firmware/include/diacritic.h
new file mode 100644
index 0000000000..ebcb3bb79a
--- /dev/null
+++ b/firmware/include/diacritic.h
@@ -0,0 +1,26 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2009 Tomer Shalev
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#ifndef _DIACRITIC_H_
+#define _DIACRITIC_H_
+#include "system.h"
+
+int is_diacritic(unsigned short char_code, bool *is_rtl);
+#endif