ri Jul 26 18:48:49 2002 Owen Taylor <otaylor@redhat.com>

        * configure.in modules/thai/Makefile.am
          modules/thai/thai-shaper.[ch]
          modules/thai/thai-xft.c modules/thai/thai-x.c:
        Patch from Theppitak Karoonboonyanan that factors
        out common code from thai-x.c and adds a new
        Xft shaper for Thai. (#78346)

1 files changed, 720 insertions, 0 deletions

diff --git a/modules/thai/thai-shaper.c b/modules/thai/thai-shaper.c
new file mode 100644
index 00000000..1c1a9785
--- /dev/null
+++ b/modules/thai/thai-shaper.c
@@ -0,0 +1,720 @@
+/* Pango
+ * thai-shaper.c:
+ *
+ * Copyright (C) 1999 Red Hat Software
+ * Author: Owen Taylor <otaylor@redhat.com>
+ *
+ * Software and Language Engineering Laboratory, NECTEC
+ * Author: Theppitak Karoonboonyanan <thep@links.nectec.or.th>
+ *
+ * Copyright (c) 1996-2000 by Sun Microsystems, Inc.
+ * Author: Chookij Vanatham <Chookij.Vanatham@Eng.Sun.COM>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+
+#include <string.h>
+
+#include <glib.h>
+#include "pangoxft.h"
+#include "pango-engine.h"
+#include "thai-shaper.h"
+
+#define MAX_CLUSTER_CHRS	256
+#define MAX_GLYPHS		256
+
+/* Define TACTIS character classes */
+#define CTRL			0
+#define NON			1
+#define CONS			2
+#define LV			3
+#define FV1			4
+#define FV2			5
+#define FV3			6
+#define BV1			7
+#define BV2			8
+#define BD			9
+#define TONE			10
+#define AD1			11
+#define AD2			12
+#define AD3			13
+#define AV1			14
+#define AV2			15
+#define AV3			16
+
+#define _ND			0
+#define _NC			1
+#define _UC			(1<<1)
+#define _BC			(1<<2)
+#define _SC			(1<<3)
+#define _AV			(1<<4)
+#define _BV			(1<<5)
+#define _TN			(1<<6)
+#define _AD			(1<<7)
+#define _BD			(1<<8)
+#define _AM			(1<<9)
+
+#define NoTailCons		_NC
+#define UpTailCons		_UC
+#define BotTailCons		_BC
+#define SpltTailCons		_SC
+#define Cons			(NoTailCons|UpTailCons|BotTailCons|SpltTailCons)
+#define AboveVowel		_AV
+#define BelowVowel		_BV
+#define Tone			_TN
+#define AboveDiac		_AD
+#define BelowDiac		_BD
+#define SaraAm			_AM
+
+#define char_class(wc)		TAC_char_class[(unsigned int)(wc)]
+#define is_char_type(wc, mask)	(char_type_table[ucs2tis ((wc))] & (mask))
+
+/* All combining marks for Thai fall in the range U+0E30-U+0E50,
+ * so we confine our data tables to that range, and use
+ * default values for characters outside those ranges.
+ */
+
+/* Map from code point to group used for rendering with XTIS fonts
+ * (0 == base character)
+ */
+static const char groups[32] = {
+  0, 1, 0, 0, 1, 1, 1, 1,
+  1, 1, 1, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 2,
+  2, 2, 2, 2, 2, 2, 1, 0
+};
+
+/* Map from code point to index within group 1
+ * (0 == no combining mark from group 1)
+ */   
+static const char group1_map[32] = {
+  0, 1, 0, 0, 2, 3, 4, 5,
+  6, 7, 8, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0
+};
+
+/* Map from code point to index within group 2
+ * (0 == no combining mark from group 2)
+ */   
+static const char group2_map[32] = {
+  0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 0,
+  0, 0, 0, 0, 0, 0, 0, 1,
+  2, 3, 4, 5, 6, 7, 1, 0
+};
+
+static const gint char_type_table[256] = {
+  /*       0,   1,   2,   3,   4,   5,   6,   7,
+           8,   9,   A,   B,   C,   D,   E,   F  */
+
+  /*00*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*10*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*20*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*30*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*40*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*50*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*60*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*70*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*80*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+  /*90*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+		
+  /*A0*/ _ND, _NC, _NC, _NC, _NC, _NC, _NC, _NC,
+         _NC, _NC, _NC, _NC, _NC, _SC, _BC, _BC,
+  /*B0*/ _SC, _NC, _NC, _NC, _NC, _NC, _NC, _NC,
+         _NC, _NC, _NC, _UC, _NC, _UC, _NC, _UC,
+  /*C0*/ _NC, _NC, _NC, _NC, _ND, _NC, _ND, _NC,
+         _NC, _NC, _NC, _NC, _UC, _NC, _NC, _ND,
+  /*D0*/ _ND, _AV, _ND, _AM, _AV, _AV, _AV, _AV,
+         _BV, _BV, _BD, _ND, _ND, _ND, _ND, _ND,
+  /*E0*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _AD,
+         _TN, _TN, _TN, _TN, _AD, _AD, _AD, _ND,
+  /*F0*/ _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+         _ND, _ND, _ND, _ND, _ND, _ND, _ND, _ND,
+};
+
+static const gint TAC_char_class[256] = {
+  /*	   0,   1,   2,   3,   4,   5,   6,   7,
+           8,   9,   A,   B,   C,   D,   E,   F  */
+
+  /*00*/ CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+         CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+  /*10*/ CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+         CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+  /*20*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON, NON,
+  /*30*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON, NON,
+  /*40*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON, NON,
+  /*50*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON, NON,
+  /*60*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON, NON,
+  /*70*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON,CTRL,
+  /*80*/ CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+         CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+  /*90*/ CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+         CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,CTRL,
+  /*A0*/  NON,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
+         CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
+  /*B0*/ CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
+         CONS,CONS,CONS,CONS,CONS,CONS,CONS,CONS,
+  /*C0*/ CONS,CONS,CONS,CONS, FV3,CONS, FV3,CONS,
+         CONS,CONS,CONS,CONS,CONS,CONS,CONS, NON,
+  /*D0*/  FV1, AV2, FV1, FV1, AV1, AV3, AV2, AV3,
+          BV1, BV2,  BD, NON, NON, NON, NON, NON,
+  /*E0*/   LV,  LV,  LV,  LV,  LV, FV2, NON, AD2,
+         TONE,TONE,TONE,TONE, AD1, AD1, AD3, NON,
+  /*F0*/  NON, NON, NON, NON, NON, NON, NON, NON,
+          NON, NON, NON, NON, NON, NON, NON,CTRL,
+};
+
+static const gchar TAC_compose_and_input_check_type_table[17][17] = {
+      /* Cn */ /* 0,   1,   2,   3,   4,   5,   6,   7,
+                  8,   9,   A,   B,   C,   D,   E,   F       */
+  /* Cn-1 00 */	{ 'X', 'A', 'A', 'A', 'A', 'A', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 10 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 20 */      { 'X', 'A', 'A', 'A', 'A', 'S', 'A', 'C',
+                'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C', 'C' },
+  /* 30 */      {'X', 'S', 'A', 'S', 'S', 'S', 'S', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 40 */      { 'X', 'S', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 50 */      { 'X', 'A', 'A', 'A', 'A', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 60 */      { 'X', 'A', 'A', 'A', 'S', 'A', 'S', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 70 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'C', 'C', 'R', 'R', 'R', 'R', 'R' },
+  /* 80 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'C', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* 90 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* A0 */      { 'X', 'A', 'A', 'A', 'A', 'A', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* B0 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* C0 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* D0 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R', 'R' },
+  /* E0 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'C', 'C', 'R', 'R', 'R', 'R', 'R' },
+  /* F0 */      { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+                'R', 'R', 'C', 'R', 'R', 'R', 'R', 'R', 'R' },
+                { 'X', 'A', 'A', 'A', 'S', 'S', 'A', 'R',
+ 	        'R', 'R', 'C', 'R', 'C', 'R', 'R', 'R', 'R' }
+};
+
+typedef struct {
+  gint ShiftDown_TONE_AD[8];
+  gint ShiftDownLeft_TONE_AD[8];
+  gint ShiftLeft_TONE_AD[8];
+  gint ShiftLeft_AV[7];
+  gint ShiftDown_BV_BD[3];
+  gint TailCutCons[4];
+} ThaiShapeTable;
+
+#define shiftdown_tone_ad(c,tbl)      ((tbl)->ShiftDown_TONE_AD[(c)-0xE7])
+#define shiftdownleft_tone_ad(c,tbl)  ((tbl)->ShiftDownLeft_TONE_AD[(c)-0xE7])
+#define shiftleft_tone_ad(c,tbl)      ((tbl)->ShiftLeft_TONE_AD[(c)-0xE7])
+#define shiftleft_av(c,tbl)           ((tbl)->ShiftLeft_AV[(c)-0xD1])
+#define shiftdown_bv_bd(c,tbl)        ((tbl)->ShiftDown_BV_BD[(c)-0xD8])
+#define tailcutcons(c,tbl)            ((tbl)->TailCutCons[(c)-0xAD])
+
+/* No adjusted vowel/tonemark glyphs (tis620-0)
+ */
+static const ThaiShapeTable tis620_0_shape_table = {
+    { 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE },
+    { 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE },
+    { 0xE7, 0xE8, 0xE9, 0xEA, 0xEB, 0xEC, 0xED, 0xEE },
+    { 0xD1, 0x00, 0x00, 0xD4, 0xD5, 0xD6, 0xD7 },
+    { 0xD8, 0xD9, 0xDA },
+    { 0xAD, 0x00, 0x00, 0xB0 }
+};
+
+/* Macintosh
+ */
+static const ThaiShapeTable Mac_shape_table = {
+  { 0xE7, 0x88, 0x89, 0x8A, 0x8B, 0x8C, 0xED, 0xEE },
+  { 0x93, 0x83, 0x84, 0x85, 0x86, 0x87, 0x8F, 0xEE },
+  { 0x93, 0x98, 0x99, 0x9A, 0x9B, 0x9C, 0x8F, 0xEE },
+  { 0x92, 0x00, 0x00, 0x94, 0x95, 0x96, 0x97 },
+  { 0xD8, 0xD9, 0xDA },
+  { 0xAD, 0x00, 0x00, 0xB0 }
+};
+
+/* Microsoft Window
+ */
+static const ThaiShapeTable Win_shape_table = {
+    { 0xE7, 0x8B, 0x8C, 0x8D, 0x8E, 0x8F, 0xED, 0xEE },
+    { 0x9A, 0x86, 0x87, 0x88, 0x89, 0x8A, 0x99, 0xEE },
+    { 0x9A, 0x9B, 0x9C, 0x9D, 0x9E, 0x9F, 0x99, 0xEE },
+    { 0x98, 0x00, 0x00, 0x81, 0x82, 0x83, 0x84 },
+    { 0xFC, 0xFD, 0xFE },
+    { 0x90, 0x00, 0x00, 0x80 }
+};
+
+static void
+add_glyph (ThaiFontInfo     *font_info, 
+	   PangoGlyphString *glyphs, 
+	   gint              cluster_start, 
+	   PangoGlyph        glyph,
+	   gboolean          combining)
+{
+  PangoRectangle ink_rect, logical_rect;
+  gint index = glyphs->num_glyphs;
+
+  pango_glyph_string_set_size (glyphs, index + 1);
+  
+  glyphs->glyphs[index].glyph = glyph;
+  glyphs->glyphs[index].attr.is_cluster_start = combining ? 0 : 1;
+  
+  glyphs->log_clusters[index] = cluster_start;
+
+  pango_font_get_glyph_extents (font_info->font,
+				glyphs->glyphs[index].glyph, &ink_rect, &logical_rect);
+
+  if (combining)
+    {
+      glyphs->glyphs[index].geometry.x_offset =
+	glyphs->glyphs[index - 1].geometry.width;
+      glyphs->glyphs[index].geometry.width =
+	logical_rect.width + glyphs->glyphs[index - 1].geometry.width;
+      glyphs->glyphs[index - 1].geometry.width = 0;
+    }
+  else
+    {
+      if (logical_rect.width > 0)
+        {
+	 glyphs->glyphs[index].geometry.x_offset = 0;
+	 glyphs->glyphs[index].geometry.width = logical_rect.width;
+	}
+      else
+        {
+	 glyphs->glyphs[index].geometry.x_offset = ink_rect.width;
+	 glyphs->glyphs[index].geometry.width = ink_rect.width;
+        }
+    }
+  glyphs->glyphs[index].geometry.y_offset = 0;
+}
+
+static gint
+get_adjusted_glyphs_list (ThaiFontInfo *font_info,
+			  gunichar *cluster,
+			  gint num_chrs,
+			  PangoGlyph *glyph_lists,
+			  const ThaiShapeTable *shaping_table)
+{
+  switch (num_chrs)
+    {
+      case 1:
+        if (is_char_type (cluster[0], BelowVowel|BelowDiac|AboveVowel|AboveDiac|Tone))
+	  {
+	    if (font_info->font_set == THAI_FONT_TIS)
+	      glyph_lists[0] = make_glyph (font_info, 0x20);
+	    else
+	      glyph_lists[0] = make_glyph (font_info, 0x7F);
+            glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    return 2;
+          }
+	else
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+            return 1;
+          }
+        break;
+        
+      case 2:
+        if (is_char_type (cluster[0], NoTailCons|BotTailCons|SpltTailCons) &&
+            is_char_type (cluster[1], SaraAm))
+	  {
+            glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+            glyph_lists[1] = make_glyph (font_info, 0xED);
+            glyph_lists[2] = make_glyph (font_info, 0xD2);
+            return 3;
+          }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+          	 is_char_type (cluster[1], SaraAm))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+            glyph_lists[1] = make_glyph (font_info,
+					shiftleft_tone_ad (0xED, shaping_table));
+            glyph_lists[2] = make_glyph (font_info, 0xD2);
+            return 3;
+          }
+	else if (is_char_type (cluster[0], NoTailCons|BotTailCons|SpltTailCons) &&
+          	 is_char_type (cluster[1], AboveVowel))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    return 2;
+          }
+	else if (is_char_type (cluster[0], NoTailCons|BotTailCons|SpltTailCons) &&
+          	 is_char_type (cluster[1], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+		    	shiftdown_tone_ad (ucs2tis (cluster[1]), shaping_table));
+	    return 2;
+	  }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+          	 is_char_type (cluster[1], AboveVowel))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+		    	shiftleft_av (ucs2tis (cluster[1]), shaping_table));
+	    return 2;
+          }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+          	 is_char_type (cluster[1], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+			shiftdownleft_tone_ad (ucs2tis (cluster[1]), shaping_table));
+	    return 2;
+	  }
+	else if (is_char_type (cluster[0], NoTailCons|UpTailCons) &&
+          	 is_char_type (cluster[1], BelowVowel|BelowDiac))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    return 2;
+          }
+	else if (is_char_type (cluster[0], BotTailCons) &&
+		 is_char_type (cluster[1], BelowVowel|BelowDiac))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info,
+			shiftdown_bv_bd (ucs2tis (cluster[1]), shaping_table));
+	    return 2;
+	  }
+	else if (is_char_type (cluster[0], SpltTailCons) &&
+          	 is_char_type (cluster[1], BelowVowel|BelowDiac))
+	  {
+	    glyph_lists[0] = make_glyph (font_info,
+		    		tailcutcons (ucs2tis (cluster[0]), shaping_table));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    return 2;
+	  }
+	else
+	  {
+	    if (font_info->font_set == THAI_FONT_TIS)
+	      glyph_lists[0] = make_glyph (font_info, 0x20);
+	    else
+	      glyph_lists[0] = make_glyph (font_info, 0x7F);
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[2] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    return 3;
+	  }
+        break;
+          
+      case 3:
+        if (is_char_type (cluster[0], NoTailCons|BotTailCons|SpltTailCons) &&
+            is_char_type (cluster[1], Tone) &&
+            is_char_type (cluster[2], SaraAm))
+	  {
+            glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+            glyph_lists[1] = make_glyph (font_info, 0xED);
+            glyph_lists[2] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+            glyph_lists[3] = make_glyph (font_info, 0xD2);
+            return 4;
+          }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+		 is_char_type (cluster[1], Tone) &&
+		 is_char_type (cluster[2], SaraAm))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+				shiftleft_tone_ad (0xED, shaping_table));
+	    glyph_lists[2] = make_glyph (font_info,
+		    		shiftleft_tone_ad (ucs2tis (cluster[1]), shaping_table));
+	    glyph_lists[3] = make_glyph (font_info, 0xD2);
+	    return 4;
+	  }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+		 is_char_type (cluster[1], AboveVowel) &&
+		 is_char_type (cluster[2], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+				shiftleft_av (ucs2tis (cluster[1]), shaping_table));
+	    glyph_lists[2] = make_glyph (font_info,
+		    		shiftleft_tone_ad (ucs2tis (cluster[2]), shaping_table));
+	    return 3;
+	  }
+	else if (is_char_type (cluster[0], UpTailCons) &&
+		 is_char_type (cluster[1], BelowVowel) &&
+		 is_char_type (cluster[2], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    glyph_lists[2] = make_glyph (font_info,
+			shiftdownleft_tone_ad (ucs2tis (cluster[2]), shaping_table));
+	    return 3;
+	  }
+	else if (is_char_type (cluster[0], NoTailCons) &&
+		 is_char_type (cluster[1], BelowVowel) &&
+		 is_char_type (cluster[2], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    glyph_lists[2] =
+		make_glyph (font_info,
+			shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
+	    return 3;
+	  }
+	else if (is_char_type (cluster[0], SpltTailCons) &&
+		 is_char_type (cluster[1], BelowVowel) &&
+		 is_char_type (cluster[2], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] = make_glyph (font_info,
+		    		tailcutcons (ucs2tis (cluster[0]), shaping_table));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    glyph_lists[2] = make_glyph (font_info,
+		    		shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
+	    return 3;
+	  }
+	else if (is_char_type (cluster[0], BotTailCons) &&
+		 is_char_type (cluster[1], BelowVowel) &&
+		 is_char_type (cluster[2], AboveDiac|Tone))
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] = make_glyph (font_info,
+		    		shiftdown_bv_bd (ucs2tis (cluster[1]), shaping_table));
+	    glyph_lists[2] = make_glyph (font_info,
+				shiftdown_tone_ad (ucs2tis (cluster[2]), shaping_table));
+	    return 3;
+	  }
+	else
+	  {
+	    glyph_lists[0] =
+		make_glyph (font_info, ucs2tis (cluster[0]));
+	    glyph_lists[1] =
+		make_glyph (font_info, ucs2tis (cluster[1]));
+	    glyph_lists[2] =
+		make_glyph (font_info, ucs2tis (cluster[2]));
+	    return 3;
+	  }
+      break;
+    }
+
+    return 0;
+}
+
+static gint
+get_glyphs_list (ThaiFontInfo	*font_info,
+		 gunichar	*cluster,
+		 gint		num_chrs,
+		 PangoGlyph	*glyph_lists)
+{
+  PangoGlyph glyph;
+  gint xtis_index;
+  gint i;
+
+  switch (font_info->font_set)
+    {
+      case THAI_FONT_NONE:
+        for (i=0; i < num_chrs; i++)
+	  glyph_lists[i] = pango_xft_font_get_unknown_glyph (font_info->font, glyph_lists[i]);
+        return num_chrs;
+
+      case THAI_FONT_XTIS:
+        /* If we are rendering with an XTIS font, we try to find a precomposed
+         * glyph for the cluster.
+         */
+        xtis_index = 0x100 * (cluster[0] - 0xe00 + 0x20) + 0x30;
+        if (cluster[1])
+	    xtis_index +=8 * group1_map[cluster[1] - 0xe30];
+        if (cluster[2])
+	    xtis_index += group2_map[cluster[2] - 0xe30];
+        glyph = make_glyph (font_info, xtis_index);
+        if (pango_x_has_glyph (font_info->font, glyph)) {
+            glyph_lists[0] = glyph;
+            return 1;
+        }
+        for (i=0; i < num_chrs; i++)
+	  glyph_lists[i] =
+	      make_glyph (font_info,
+			0x100 * (cluster[i] - 0xe00 + 0x20) + 0x30);
+        return num_chrs;
+      
+      case THAI_FONT_TIS:
+	/* TIS620-0 + Wtt2.0 Extension
+	 */
+        return get_adjusted_glyphs_list (font_info, cluster,
+		num_chrs, glyph_lists, &tis620_0_shape_table);
+      
+      case THAI_FONT_TIS_MAC:
+	/* MacIntosh Extension
+	 */
+        return get_adjusted_glyphs_list (font_info, cluster,
+		num_chrs, glyph_lists, &Mac_shape_table);
+      
+      case THAI_FONT_TIS_WIN:
+	/* Microsoft Extension
+	 */
+        return get_adjusted_glyphs_list (font_info, cluster,
+		num_chrs, glyph_lists, &Win_shape_table);
+      
+      case THAI_FONT_ISO10646:
+        for (i=0; i < num_chrs; i++)
+          glyph_lists[i] = make_glyph (font_info, cluster[i]);
+        return num_chrs;
+    }
+
+  return 0;			/* Quiet GCC */
+}
+
+static void
+add_cluster (ThaiFontInfo	*font_info,
+	     PangoGlyphString	*glyphs,
+	     gint		cluster_start,
+	     gunichar		*cluster,
+	     gint		num_chrs)
+{
+  PangoGlyph glyphs_list[MAX_GLYPHS];
+  gint num_glyphs;
+  gint i;
+  
+  num_glyphs = get_glyphs_list(font_info, cluster, num_chrs, glyphs_list);
+  for (i=0; i<num_glyphs; i++)
+       add_glyph (font_info, glyphs, cluster_start, glyphs_list[i],
+	    		i == 0 ? FALSE : TRUE);
+}
+
+static gboolean
+is_wtt_composible (gunichar cur_wc, gunichar nxt_wc)
+{
+  switch (TAC_compose_and_input_check_type_table[char_class (ucs2tis (cur_wc))]
+						[char_class (ucs2tis (nxt_wc))])
+    {
+      case 'A':
+      case 'S':
+      case 'R':
+      case 'X':
+        return FALSE;
+
+      case 'C':
+        return TRUE;
+    }
+
+  g_assert_not_reached ();
+  return FALSE;
+}
+
+static const char *
+get_next_cluster(const char	*text,
+		 gint		length,
+		 gunichar       *cluster,
+		 gint		*num_chrs)
+{  
+  const char *p;
+  gint n_chars = 0;
+  
+  p = text;
+  while (p < text + length && n_chars < 3)  
+    {
+      gunichar current = g_utf8_get_char (p);
+      
+      if (n_chars == 0 ||
+	  is_wtt_composible ((gunichar)(cluster[n_chars - 1]), current) ||
+	  (n_chars == 1 &&
+	   is_char_type (cluster[0], Cons) && 
+	   is_char_type (current, SaraAm)) ||
+	  (n_chars == 2 &&
+	   is_char_type (cluster[0], Cons) &&
+	   is_char_type (cluster[1], Tone) &&
+	   is_char_type (current, SaraAm)))
+	{
+	  cluster[n_chars++] = current;
+	  p = g_utf8_next_char (p);
+	}
+      else
+	break;
+    }
+
+  *num_chrs = n_chars;
+  return p;
+}
+
+void 
+thai_engine_shape (PangoFont        *font,
+		   const char       *text,
+		   gint              length,
+		   PangoAnalysis    *analysis,
+		   PangoGlyphString *glyphs)
+{
+  ThaiFontInfo *font_info;
+  const char *p;
+  const char *log_cluster;
+  gunichar cluster[MAX_CLUSTER_CHRS];
+  gint num_chrs;
+
+  pango_glyph_string_set_size (glyphs, 0);
+
+  font_info = get_font_info (font);
+
+  p = text;
+  while (p < text + length)
+    {
+	log_cluster = p;
+	p = get_next_cluster (p, text + length - p, cluster, &num_chrs);
+	add_cluster (font_info, glyphs, log_cluster - text, cluster, num_chrs);
+    }
+}
+