Port pre-base-mantra fixup code from ICU, as needed for Tamil and

Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>

        * modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
        modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
        fixup code from ICU, as needed for Tamil and Malayalam.
        (Based on patch from Sivaraj Doddannan, #111166)

12 files changed, 274 insertions, 18 deletions

diff --git a/ChangeLog b/ChangeLog
index a2bf4ff9..55906fcb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>
+
+	* modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
+	modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
+	fixup code from ICU, as needed for Tamil and Malayalam.
+	(Based on patch from Sivaraj Doddannan, #111166)
+
 Fri Jul 25 11:06:14 2003  Owen Taylor  <otaylor@redhat.com>
 
 	* modules/indic/indic-ot.[ch]: Port of some fixes from
diff --git a/ChangeLog.pre-1-10 b/ChangeLog.pre-1-10
index a2bf4ff9..55906fcb 100644
--- a/ChangeLog.pre-1-10
+++ b/ChangeLog.pre-1-10
@@ -1,3 +1,10 @@
+Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>
+
+	* modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
+	modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
+	fixup code from ICU, as needed for Tamil and Malayalam.
+	(Based on patch from Sivaraj Doddannan, #111166)
+
 Fri Jul 25 11:06:14 2003  Owen Taylor  <otaylor@redhat.com>
 
 	* modules/indic/indic-ot.[ch]: Port of some fixes from
diff --git a/ChangeLog.pre-1-4 b/ChangeLog.pre-1-4
index a2bf4ff9..55906fcb 100644
--- a/ChangeLog.pre-1-4
+++ b/ChangeLog.pre-1-4
@@ -1,3 +1,10 @@
+Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>
+
+	* modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
+	modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
+	fixup code from ICU, as needed for Tamil and Malayalam.
+	(Based on patch from Sivaraj Doddannan, #111166)
+
 Fri Jul 25 11:06:14 2003  Owen Taylor  <otaylor@redhat.com>
 
 	* modules/indic/indic-ot.[ch]: Port of some fixes from
diff --git a/ChangeLog.pre-1-6 b/ChangeLog.pre-1-6
index a2bf4ff9..55906fcb 100644
--- a/ChangeLog.pre-1-6
+++ b/ChangeLog.pre-1-6
@@ -1,3 +1,10 @@
+Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>
+
+	* modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
+	modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
+	fixup code from ICU, as needed for Tamil and Malayalam.
+	(Based on patch from Sivaraj Doddannan, #111166)
+
 Fri Jul 25 11:06:14 2003  Owen Taylor  <otaylor@redhat.com>
 
 	* modules/indic/indic-ot.[ch]: Port of some fixes from
diff --git a/ChangeLog.pre-1-8 b/ChangeLog.pre-1-8
index a2bf4ff9..55906fcb 100644
--- a/ChangeLog.pre-1-8
+++ b/ChangeLog.pre-1-8
@@ -1,3 +1,10 @@
+Fri Jul 25 12:07:21 2003  Owen Taylor  <otaylor@redhat.com>
+
+	* modules/indic/mprefixups.[ch] modules/indic/indic-ot.[ch]
+	modules/indic/indic-{xft,ft2}.c: Port pre-base-mantra
+	fixup code from ICU, as needed for Tamil and Malayalam.
+	(Based on patch from Sivaraj Doddannan, #111166)
+
 Fri Jul 25 11:06:14 2003  Owen Taylor  <otaylor@redhat.com>
 
 	* modules/indic/indic-ot.[ch]: Port of some fixes from
diff --git a/modules/indic/Makefile.am b/modules/indic/Makefile.am
index c1a41742..a9ebc18d 100644
--- a/modules/indic/Makefile.am
+++ b/modules/indic/Makefile.am
@@ -171,7 +171,9 @@ ft2_sources =		 	\
 	indic-ft2.c		\
 	indic-ot-class-tables.c	\
 	indic-ot.c		\
-	indic-ot.h
+	indic-ot.h		\
+	mprefixups.c		\
+	mprefixups.h
 
 pango_indic_ft2_la_LDFLAGS = -export-dynamic -avoid-version -module $(no_undefined)
 pango_indic_ft2_la_LIBADD = $(indic_ft2_libadd)
diff --git a/modules/indic/indic-ft2.c b/modules/indic/indic-ft2.c
index d40881d1..5d0b6c75 100644
--- a/modules/indic/indic-ft2.c
+++ b/modules/indic/indic-ft2.c
@@ -303,7 +303,8 @@ indic_engine_shape (PangoFont        *font,
   PangoOTRuleset *gsub_ruleset = NULL, *gpos_ruleset = NULL;
   PangoEngineShapeIndic *indic_shape_engine = NULL;
   PangoIndicInfo *indic_info = NULL;
-
+  MPreFixups *mprefixups;
+ 
   g_return_if_fail (font != NULL);
   g_return_if_fail (text != NULL);
   g_return_if_fail (length >= 0);
@@ -321,14 +322,15 @@ indic_engine_shape (PangoFont        *font,
   indic_info = indic_shape_engine->indicInfo;
 
   wc_in    = expand_text (text, length, &utf8_offsets, &n_chars);
-  n_glyphs = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, NULL, NULL, NULL);
-
+ 
+  n_glyphs = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, NULL, NULL, NULL, NULL);
+  
   wc_out  = g_new (gunichar, n_glyphs);
   indices = g_new (glong,    n_glyphs);
   tags    = g_new (gulong,   n_glyphs);
 
-  n_glyphs  = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, wc_out, indices, tags);
-
+  n_glyphs  = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, wc_out, indices, tags, &mprefixups);
+  
   pango_glyph_string_set_size (glyphs, n_glyphs);
   set_glyphs(font, face, wc_out, n_glyphs, glyphs);
 
@@ -339,6 +341,13 @@ indic_engine_shape (PangoFont        *font,
       pango_ot_ruleset_shape (gsub_ruleset, glyphs, tags);
     }
 
+  /* Fix pre-modifiers for some scripts before base consonant */
+  if (mprefixups)
+    {
+      indic_mprefixups_apply (mprefixups, glyphs);
+      indic_mprefixups_free (mprefixups);
+    }
+
   /* apply default positioning */
   for (i = 0; i < glyphs->num_glyphs; i += 1)
     {
diff --git a/modules/indic/indic-ot.c b/modules/indic/indic-ot.c
index 99fdff4d..ca05ae30 100644
--- a/modules/indic/indic-ot.c
+++ b/modules/indic/indic-ot.c
@@ -7,7 +7,7 @@
  */
 
 #include "indic-ot.h"
-
+#include "mprefixups.h"
 /*
  * FIXME: should the IndicOutput stuff be moved
  * to a spereate .h and .c file just to keep the
@@ -29,13 +29,16 @@ struct _Output
     gunichar fMabove;
     gunichar fMpost;
     gunichar fLengthMark;
-    glong   fMatraIndex;
+    glong    fMatraIndex;
     gulong   fMatraTags;
+    glong    fMPreOutIndex;
+
+    MPreFixups *fMPreFixups;
 };
 
 typedef struct _Output Output;
 
-static void initOutput(Output *output, const glong *originalOffsets, gunichar *outChars, glong *charIndices, gulong *charTags)
+static void initOutput(Output *output, const glong *originalOffsets, gunichar *outChars, glong *charIndices, gulong *charTags, MPreFixups *mpreFixups)
 {
     output->fOriginalOffsets = originalOffsets;
 
@@ -47,6 +50,9 @@ static void initOutput(Output *output, const glong *originalOffsets, gunichar *o
     output->fMatraTags   = 0;
 
     output->fMpre = output->fMbelow = output->fMabove = output->fMpost = output->fLengthMark = 0;
+
+    output->fMPreOutIndex = -1;
+    output->fMPreFixups = mpreFixups;
 }
 
 static void saveMatra(Output *output, gunichar matra, IndicOTCharClass matraClass)
@@ -70,6 +76,7 @@ static void noteMatra(Output *output, const IndicOTClassTable *classTable, gunic
     IndicOTCharClass matraClass = indic_ot_get_char_class(classTable, matra);
 
     output->fMpre = output->fMbelow = output->fMabove = output->fMpost = output->fLengthMark = 0;
+    output->fMPreOutIndex = -1;
     output->fMatraIndex = matraIndex;
     output->fMatraTags = matraTags;
 
@@ -90,6 +97,12 @@ static void noteMatra(Output *output, const IndicOTClassTable *classTable, gunic
     }
 }
 
+static void noteBaseConsonant(Output *output)
+{
+    if (output->fMPreFixups && output->fMPreOutIndex >= 0) {
+        indic_mprefixups_add(output->fMPreFixups, output->fOutIndex, output->fMPreOutIndex);
+    }
+}
 static void writeChar(Output *output, gunichar ch, guint32 charIndex, gulong charTags)
 {
     if (output->fOutChars != NULL) {
@@ -104,6 +117,7 @@ static void writeChar(Output *output, gunichar ch, guint32 charIndex, gulong cha
 static void writeMpre(Output *output)
 {
     if (output->fMpre != 0) {
+        output->fMPreOutIndex = output->fOutIndex;
         writeChar(output, output->fMpre, output->fMatraIndex, output->fMatraTags);
     }
 }
@@ -144,12 +158,17 @@ static glong getOutputIndex(Output *output)
 #define false 0
 #define true  1
 
-glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong char_count, const IndicOTClassTable *class_table, gunichar *out_chars, glong *char_indices, gulong *char_tags)
+glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong char_count, const IndicOTClassTable *class_table, gunichar *out_chars, glong *char_indices, gulong *char_tags, MPreFixups **outMPreFixups)
 {
+    MPreFixups *mpreFixups = NULL;
     Output output;
     glong i, prev = 0;
 
-    initOutput(&output, utf8_offsets, out_chars, char_indices, char_tags);
+    if (outMPreFixups && (class_table->scriptFlags & SF_MPRE_FIXUP)) {
+	mpreFixups = indic_mprefixups_new (char_count);
+    }
+
+    initOutput(&output, utf8_offsets, out_chars, char_indices, char_tags, mpreFixups);
 
     while (prev < char_count) {
         glong syllable = indic_ot_find_syllable(class_table, chars, prev, char_count);
@@ -306,6 +325,9 @@ glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong c
 		}
 	    }
 
+            /* note the base consonant for post-GSUB fixups */
+	    noteBaseConsonant(&output);
+	    
 	    /* write base consonant */
 	    for (i = baseConsonant; i < bcSpan; i += 1) {
 		writeChar(&output, chars[i], /*i*/ prev, nukt_p);
@@ -401,6 +423,9 @@ glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong c
         prev = syllable;
     }
 
+    if (mpreFixups) {
+	*outMPreFixups = mpreFixups;
+    }
+    
     return getOutputIndex(&output);
 }
-
diff --git a/modules/indic/indic-ot.h b/modules/indic/indic-ot.h
index 2e831f9a..caf229d4 100644
--- a/modules/indic/indic-ot.h
+++ b/modules/indic/indic-ot.h
@@ -12,6 +12,7 @@
 #include <freetype/freetype.h>
 #include <pango/pango-glyph.h>
 #include <pango/pango-types.h>
+#include "mprefixups.h"
 
 G_BEGIN_DECLS
 
@@ -241,7 +242,7 @@ gboolean indic_ot_has_below_base_form(const IndicOTClassTable *class_table, guni
 
 glong indic_ot_find_syllable(const IndicOTClassTable *class_table, const gunichar *chars, glong prev, glong char_count);
 
-glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong char_count, const IndicOTClassTable *class_table, gunichar *out_chars, glong *char_indices, gulong *char_tags);
+glong indic_ot_reorder(const gunichar *chars, const glong *utf8_offsets, glong char_count, const IndicOTClassTable *class_table, gunichar *out_chars, glong *char_indices, gulong *char_tags, MPreFixups **outMPreFixups);
 
 #endif /* PANGO_ENABLE_ENGINE */
 
diff --git a/modules/indic/indic-xft.c b/modules/indic/indic-xft.c
index 5d5afa2d..5cafdd29 100644
--- a/modules/indic/indic-xft.c
+++ b/modules/indic/indic-xft.c
@@ -302,7 +302,8 @@ indic_engine_shape (PangoFont        *font,
   PangoOTRuleset *gsub_ruleset = NULL, *gpos_ruleset = NULL;
   PangoEngineShapeIndic *indic_shape_engine = NULL;
   PangoIndicInfo *indic_info = NULL;
-
+  MPreFixups *mprefixups;
+ 
   g_return_if_fail (font != NULL);
   g_return_if_fail (text != NULL);
   g_return_if_fail (length >= 0);
@@ -320,14 +321,15 @@ indic_engine_shape (PangoFont        *font,
   indic_info = indic_shape_engine->indicInfo;
 
   wc_in    = expand_text (text, length, &utf8_offsets, &n_chars);
-  n_glyphs = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, NULL, NULL, NULL);
-
+ 
+  n_glyphs = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, NULL, NULL, NULL, NULL);
+  
   wc_out  = g_new (gunichar, n_glyphs);
   indices = g_new (glong,    n_glyphs);
   tags    = g_new (gulong,   n_glyphs);
 
-  n_glyphs  = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, wc_out, indices, tags);
-
+  n_glyphs  = indic_ot_reorder (wc_in, utf8_offsets, n_chars, indic_info->classTable, wc_out, indices, tags, &mprefixups);
+  
   pango_glyph_string_set_size (glyphs, n_glyphs);
   set_glyphs(font, face, wc_out, n_glyphs, glyphs);
 
@@ -338,6 +340,13 @@ indic_engine_shape (PangoFont        *font,
       pango_ot_ruleset_shape (gsub_ruleset, glyphs, tags);
     }
 
+  /* Fix pre-modifiers for some scripts before base consonant */
+  if (mprefixups)
+    {
+      indic_mprefixups_apply (mprefixups, glyphs);
+      indic_mprefixups_free (mprefixups);
+    }
+
   /* apply default positioning */
   for (i = 0; i < glyphs->num_glyphs; i += 1)
     {
diff --git a/modules/indic/mprefixups.c b/modules/indic/mprefixups.c
new file mode 100644
index 00000000..29b126d0
--- /dev/null
+++ b/modules/indic/mprefixups.c
@@ -0,0 +1,125 @@
+/* 
+ * mprefixups.h: Handle left matra placement 
+ *
+ * Author: Sivaraj Doddannan
+ * Ported from IBM's ICU engine.  Original copyright:
+ * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
+ *
+ * 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 <pango/pango-types.h>
+#include "mprefixups.h"
+#include <stdio.h>
+
+struct _FixupData
+{
+    glong fBaseIndex;
+    glong fMPreIndex;
+};
+
+MPreFixups *indic_mprefixups_new(glong char_count)
+{
+    MPreFixups *mprefixups = g_new (MPreFixups, 1);
+    mprefixups->fFixupCount = 0;
+    mprefixups->fFixupData = g_new (FixupData, char_count);
+
+    return mprefixups;
+}
+
+void indic_mprefixups_free (MPreFixups *mprefixups)
+{
+    g_free (mprefixups->fFixupData);
+    g_free (mprefixups);
+}
+
+void indic_mprefixups_add (MPreFixups *mprefixups, glong baseIndex, glong mpreIndex)
+{
+    /* NOTE: don't add the fixup data if the mpre is right
+     * before the base consonant glyph.
+     */
+    if (baseIndex - mpreIndex > 1) {
+       mprefixups->fFixupData[mprefixups->fFixupCount].fBaseIndex = baseIndex;
+       mprefixups->fFixupData[mprefixups->fFixupCount].fMPreIndex = mpreIndex;
+    
+       mprefixups->fFixupCount += 1;
+    }
+}
+
+void indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs)
+{
+    glong fixup;
+
+    for (fixup = 0; fixup < mprefixups->fFixupCount; fixup += 1) {
+	glong baseIndex = mprefixups->fFixupData[fixup].fBaseIndex;
+	glong mpreIndex = mprefixups->fFixupData[fixup].fMPreIndex;
+	glong mpreLimit, mpreCount, moveCount, mpreDest;
+	glong i;
+	PangoGlyph *mpreSave;
+	int *clusterSave;
+
+	/* determine post GSUB location of baseIndex and mpreIndex */
+	gboolean no_base = TRUE;
+	for (i = 0; i<glyphs->num_glyphs; i++) {
+	    if (glyphs->log_clusters[i] == baseIndex) {
+		baseIndex = i + 1;
+		no_base = FALSE;
+	    }
+	    if (glyphs->log_clusters[i] == mpreIndex)
+		mpreIndex = i;
+	}
+	if (no_base)
+	    break;
+
+	mpreLimit = mpreIndex + 1;
+
+	while (glyphs->glyphs[baseIndex].glyph == 0xFFFF || glyphs->glyphs[baseIndex].glyph == 0xFFFE) {
+	    baseIndex -= 1;
+	}
+
+	while (glyphs->glyphs[mpreIndex].glyph == 0xFFFF || glyphs->glyphs[mpreIndex].glyph == 0xFFFE) {
+	    mpreLimit += 1;
+	}
+      
+	if (mpreLimit == baseIndex) {
+	    continue;
+	}
+
+	mpreCount  = mpreLimit - mpreIndex;
+	moveCount  = baseIndex - mpreLimit;
+	mpreDest   = baseIndex - mpreCount - 1;
+
+	mpreSave    = g_new (PangoGlyph, mpreCount);
+	clusterSave = g_new (int, mpreCount);
+
+	for (i = 0; i < mpreCount; i += 1) {
+	    mpreSave[i] = glyphs->glyphs[mpreIndex + i].glyph;
+	    clusterSave[i] = glyphs->log_clusters[mpreIndex + i];
+	}
+
+	for (i = 0; i < moveCount; i += 1) {
+	    glyphs->glyphs[mpreIndex + i].glyph = glyphs->glyphs[mpreLimit + i].glyph;
+	    glyphs->log_clusters[mpreIndex + i] = glyphs->log_clusters[mpreLimit + i];
+	}
+
+	for (i = 0; i < mpreCount; i += 1) {
+	    glyphs->glyphs[mpreDest + i].glyph = mpreSave[i];
+	    glyphs->log_clusters[mpreDest + i] = clusterSave[i];
+	}
+ 
+	g_free(mpreSave);
+    } 
+}
diff --git a/modules/indic/mprefixups.h b/modules/indic/mprefixups.h
new file mode 100644
index 00000000..4bab8cac
--- /dev/null
+++ b/modules/indic/mprefixups.h
@@ -0,0 +1,50 @@
+/* 
+ * mprefixups.c: Handle left matra placement 
+ *
+ * Author: Sivaraj Doddannan
+ * Ported from IBM's ICU engine.  Original copyright:
+ * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
+ *
+ * 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.
+ */
+
+#ifndef __MPREFIXUPS_H
+#define __MPREFIXUPS_H
+
+#include <pango/pango-types.h>
+#include <pango/pango-glyph.h>
+
+G_BEGIN_DECLS
+
+typedef struct _FixupData FixupData;
+
+struct _MPreFixups {
+  glong		fFixupCount;
+  FixupData	*fFixupData;
+};
+
+typedef struct _MPreFixups MPreFixups;
+
+MPreFixups *indic_mprefixups_new(glong char_count);
+void        indic_mprefixups_free(MPreFixups *mprefixups);
+void        indic_mprefixups_add(MPreFixups *mprefixups, glong baseIndex, glong mpreIndex);
+void        indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs);
+ 
+
+G_END_DECLS
+
+#endif
+