Rework opentype interfaces and other changes to make GPOS work for Arabic.

Sun Feb 29 09:25:13 2004  Owen Taylor  <otaylor@redhat.com>

        Rework opentype interfaces and other changes to make GPOS
        work for Arabic. (Most of #117282, #121060)

        * pango/opentype/otlbuffer.[ch]: OTL_Buffer that
        acts as a replacement for the separate GSUB and
        GPOS string structures and hides many of the internal
        details.

        * pango/opentype/ftxgsub.[ch] pango/opentype/ftxgpos.[ch]:
        Adapt to OTL_Buffer.

        * pango/opentype/ftxgpos.c: Redo handling of cursive
        chains so that it actually works.

        * pango/pango-ot.h pango/opentype/pango-ot-buffer.c:
        Pango wrapper around OTL_Buffer.

        * pango/pango-ot.h pango/pango-ot-ruleset.c pango/pango-ot-buffer.c:
        Split pango_ot_ruleset_shape() into pango_ot_ruleset_substitute(),
        pango_ot_ruleset_position(), make them act on
        PangoOTBuffer, add a separate pango_ot_buffer_output()
        which does the default positioning and writes to a
        PangoGlyphString.

        * modules/arabic/arabic-fc.c modules/indic/indic-fc.c
        modules/indic/mprefixups.[ch]: Adapt to new OpenType
        interfaces; add GPOS features for Arabic.

        * pango/opentype/pango-ot-info.c: Don't derive class information
        from Unicode properties for Arabic presentation forms,
        let the shaping process derive the properties.

4 files changed, 33 insertions, 58 deletions

diff --git a/modules/indic/indic-fc.c b/modules/indic/indic-fc.c
index 68b28662..45eb48f8 100644
--- a/modules/indic/indic-fc.c
+++ b/modules/indic/indic-fc.c
@@ -241,20 +241,18 @@ get_gpos_ruleset (FT_Face face, PangoIndicInfo *indic_info)
   return ruleset;
 }
 static void
-set_glyphs (PangoFont *font, FT_Face face, const gunichar *wcs, glong n_glyphs, PangoGlyphString *glyphs)
+set_glyphs (PangoFont *font, FT_Face face, const gunichar *wcs, gulong *tags, glong n_glyphs, PangoOTBuffer *buffer)
 {
   gint i;
 
   g_assert (face);
 
-  pango_glyph_string_set_size (glyphs, n_glyphs);
-
   for (i = 0; i < n_glyphs; i += 1)
     {
-      PangoGlyph glyph = FT_Get_Char_Index (face, wcs[i]);
-
-      glyphs->glyphs[i].glyph = glyph;
-      glyphs->log_clusters[i] = i;
+      pango_ot_buffer_add_glyph (buffer,
+				 FT_Get_Char_Index (face, wcs[i]),
+				 tags[i],
+				 i);
     }
 }
 
@@ -305,6 +303,7 @@ indic_engine_shape (PangoEngineShape *engine,
   glong *indices = NULL;
   FT_Face face;
   PangoOTRuleset *gsub_ruleset = NULL, *gpos_ruleset = NULL;
+  PangoOTBuffer *buffer;
   IndicEngineFc *indic_shape_engine = NULL;
   PangoIndicInfo *indic_info = NULL;
   PangoFcFont *fc_font;
@@ -334,55 +333,27 @@ indic_engine_shape (PangoEngineShape *engine,
   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);
+  buffer = pango_ot_buffer_new (fc_font);
+  set_glyphs(font, face, wc_out, tags, n_glyphs, buffer);
 
   /* do gsub processing */
   gsub_ruleset = get_gsub_ruleset (face, indic_info);
   if (gsub_ruleset != NULL)
-    {
-      pango_ot_ruleset_shape (gsub_ruleset, glyphs, tags);
-    }
+    pango_ot_ruleset_substitute (gsub_ruleset, buffer);
 
   /* Fix pre-modifiers for some scripts before base consonant */
   if (mprefixups)
     {
-      indic_mprefixups_apply (mprefixups, glyphs);
+      indic_mprefixups_apply (mprefixups, buffer);
       indic_mprefixups_free (mprefixups);
     }
 
-  /* apply default positioning */
-  for (i = 0; i < glyphs->num_glyphs; i += 1)
-    {
-      if (glyphs->glyphs[i].glyph != 0)
-	{
-	  PangoRectangle logical_rect;
-
-	  pango_font_get_glyph_extents (font, glyphs->glyphs[i].glyph, NULL, &logical_rect);
-	  glyphs->glyphs[i].geometry.width = logical_rect.width;
-	}
-      else
-	{
-	  glyphs->glyphs[i].geometry.width = 0;
-	}
-
-      glyphs->glyphs[i].geometry.x_offset = 0;
-      glyphs->glyphs[i].geometry.y_offset = 0;
-    }
-
   /* do gpos processing */
   gpos_ruleset = get_gpos_ruleset (face, indic_info);
   if (gpos_ruleset != NULL)
-    {
-      gulong *tags_after_gsub;
-      
-      tags_after_gsub = g_new (gulong, glyphs->num_glyphs);
-      for (i = 0; i < glyphs->num_glyphs; i += 1)
-	tags_after_gsub[i] = tags[glyphs->log_clusters[i]];
-
-      pango_ot_ruleset_shape (gpos_ruleset, glyphs, tags_after_gsub);
-      
-      g_free (tags_after_gsub);
-    }
+    pango_ot_ruleset_position (gpos_ruleset, buffer);
+
+  pango_ot_buffer_output (buffer, glyphs);
 
   /* Get the right log_clusters values */
   for (i = 0; i < glyphs->num_glyphs; i += 1)
@@ -390,6 +361,7 @@ indic_engine_shape (PangoEngineShape *engine,
 
   pango_fc_font_unlock_face (fc_font);
 
+  pango_ot_buffer_destroy (buffer);
   g_free (tags);
   g_free (indices);
   g_free (wc_out);
diff --git a/modules/indic/indic-ot.c b/modules/indic/indic-ot.c
index 94a689de..211d3e9c 100644
--- a/modules/indic/indic-ot.c
+++ b/modules/indic/indic-ot.c
@@ -10,7 +10,7 @@
 #include "mprefixups.h"
 /*
  * FIXME: should the IndicOutput stuff be moved
- * to a spereate .h and .c file just to keep the
+ * to a separate .h and .c file just to keep the
  * clutter down here? (it's not really usefull
  * anyplace else, is it?)
  */
diff --git a/modules/indic/mprefixups.c b/modules/indic/mprefixups.c
index 29b126d0..183f29ce 100644
--- a/modules/indic/mprefixups.c
+++ b/modules/indic/mprefixups.c
@@ -59,7 +59,7 @@ void indic_mprefixups_add (MPreFixups *mprefixups, glong baseIndex, glong mpreIn
     }
 }
 
-void indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs)
+void indic_mprefixups_apply(MPreFixups *mprefixups, PangoOTBuffer *buffer)
 {
     glong fixup;
 
@@ -68,17 +68,22 @@ void indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs)
 	glong mpreIndex = mprefixups->fFixupData[fixup].fMPreIndex;
 	glong mpreLimit, mpreCount, moveCount, mpreDest;
 	glong i;
-	PangoGlyph *mpreSave;
+	PangoOTGlyph *glyphs;
+	int n_glyphs;
+	PangoOTGlyph *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) {
+
+	pango_ot_buffer_get_glyphs (buffer, &glyphs, &n_glyphs);
+	
+	for (i = 0; i < n_glyphs; i++) {
+	    if (glyphs[i].cluster == baseIndex) {
 		baseIndex = i + 1;
 		no_base = FALSE;
 	    }
-	    if (glyphs->log_clusters[i] == mpreIndex)
+	    if (glyphs[i].cluster == mpreIndex)
 		mpreIndex = i;
 	}
 	if (no_base)
@@ -86,11 +91,11 @@ void indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs)
 
 	mpreLimit = mpreIndex + 1;
 
-	while (glyphs->glyphs[baseIndex].glyph == 0xFFFF || glyphs->glyphs[baseIndex].glyph == 0xFFFE) {
+	while (glyphs[baseIndex].glyph == 0xFFFF || glyphs[baseIndex].glyph == 0xFFFE) {
 	    baseIndex -= 1;
 	}
 
-	while (glyphs->glyphs[mpreIndex].glyph == 0xFFFF || glyphs->glyphs[mpreIndex].glyph == 0xFFFE) {
+	while (glyphs[mpreIndex].glyph == 0xFFFF || glyphs[mpreIndex].glyph == 0xFFFE) {
 	    mpreLimit += 1;
 	}
       
@@ -102,22 +107,19 @@ void indic_mprefixups_apply(MPreFixups *mprefixups, PangoGlyphString *glyphs)
 	moveCount  = baseIndex - mpreLimit;
 	mpreDest   = baseIndex - mpreCount - 1;
 
-	mpreSave    = g_new (PangoGlyph, mpreCount);
+	mpreSave    = g_new (PangoOTGlyph, 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];
+	    mpreSave[i] = glyphs[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];
+	    glyphs[mpreIndex + i] = glyphs[mpreLimit + i];
 	}
 
 	for (i = 0; i < mpreCount; i += 1) {
-	    glyphs->glyphs[mpreDest + i].glyph = mpreSave[i];
-	    glyphs->log_clusters[mpreDest + i] = clusterSave[i];
+	    glyphs[mpreDest + i] = mpreSave[i];
 	}
  
 	g_free(mpreSave);
diff --git a/modules/indic/mprefixups.h b/modules/indic/mprefixups.h
index 4bab8cac..d09d6be5 100644
--- a/modules/indic/mprefixups.h
+++ b/modules/indic/mprefixups.h
@@ -26,6 +26,7 @@
 
 #include <pango/pango-types.h>
 #include <pango/pango-glyph.h>
+#include <pango/pango-ot.h>
 
 G_BEGIN_DECLS
 
@@ -41,7 +42,7 @@ 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);
+void        indic_mprefixups_apply(MPreFixups *mprefixups, PangoOTBuffer *buffer);
  
 
 G_END_DECLS