Correct parameters passed to MultiByteToWideChar(). Pass -1 as source

2005-04-28  Tor Lillqvist  <tml@novell.com>

	* pango/pangocairo-win32font.c (pango_cairo_win32_font_get_font_face):
	Correct parameters passed to MultiByteToWideChar(). Pass -1 as
	source string length so that the target string gets
	zero-terminated. Size of target array is in number of WCHARs, not
	number of bytes.

	Add support to pangowin32 for TrueType fonts with coverage outside
	the BMP. Fix handling of surrogate pairs in the Uniscribe
	shaper. (#302238)

	* pango/pangowin32-private.h (PangoWin32Face): Rename the
	unicode_table field to cmap. Keep track of its format (4 or 12).
	(format_12_cmap): Add struct for a format 12 cmap.

	* pango/pangowin32.c: Corresponding changes. Rename internal
	functions a bit.
	(get_format_12_cmap): New function, reads a format 12 cmap.
	(font_get_cmap): Look for both format 12 (which is preferred) and
	format 4 cmaps.
	(pango_win32_font_get_glyph_index,
	pango_win32_font_calc_coverage): Handle also format 12 cmaps.

	* modules/basic/basic-win32.c: Handle surrogate pairs in wchar_t
	strings properly.
	(unichar_index): New function. Given a wchar_t string and an index
	into it, calculate the index of the corresponding Unicode
	character. Each surrogate pair in the wchar_t is just one Unicode
	character.
	(set_up_pango_log_clusters, itemize_shape_and_place): Use
	unichar_index() instead of direct index into wchar_t string.

1 files changed, 33 insertions, 12 deletions

diff --git a/modules/basic/basic-win32.c b/modules/basic/basic-win32.c
index b4c99a97..2ffc090b 100644
--- a/modules/basic/basic-win32.c
+++ b/modules/basic/basic-win32.c
@@ -557,7 +557,7 @@ dump_glyphs_and_log_clusters (gboolean rtl,
 	for (j = 0, charix = charix0; j < itemlen; j++, charix++)
 	  {
 	    if (j == 0 || log_clusters[j-1] != log_clusters[j])
-	      printf ("  Cluster %d: chars %d--",
+	      printf ("  Cluster %d: wchar_t %d--",
 		      clusterix, charix);
 	    if (j == itemlen - 1 || log_clusters[j] != log_clusters[j+1])
 	      {
@@ -581,8 +581,24 @@ dump_glyphs_and_log_clusters (gboolean rtl,
 
 #endif /* BASIC_WIN32_DEBUGGING */
 
+static int
+unichar_index (wchar_t *wtext,
+				int      ix)
+{
+  int i, index;
+
+  index = 0;
+  for (i = 0; i < ix; i++)
+    /* Ignore the low surrogate */
+    if (!(wtext[i] >= 0xDC00 && wtext[i] < 0xE000))
+      index++;
+
+  return index;
+}
+
 static void
-set_up_pango_log_clusters (gboolean rtl,
+set_up_pango_log_clusters (wchar_t *wtext,
+			   gboolean rtl,
 			   int      itemlen,
 			   WORD    *usp_log_clusters,
 			   int      nglyphs,
@@ -598,13 +614,13 @@ set_up_pango_log_clusters (gboolean rtl,
        * log_clusters array forwards.
        */
       int glyph0 = 0;
-      first_char_in_cluster = itemlen - 1;
+      first_char_in_cluster = unichar_index (wtext, itemlen - 1);
       for (j = itemlen - 1; j >= 0; j--)
 	{
 	  if (j < itemlen - 1 && usp_log_clusters[j+1] != usp_log_clusters[j])
 	    {
 	      /* Cluster starts */
-	      first_char_in_cluster = j;
+	      first_char_in_cluster = unichar_index (wtext, j);
 	    }
 	  if (j == 0)
 	    {
@@ -615,7 +631,7 @@ set_up_pango_log_clusters (gboolean rtl,
 	  else if (usp_log_clusters[j-1] == usp_log_clusters[j])
 	    {
 	      /* Cluster continues */
-	      first_char_in_cluster = j-1;
+	      first_char_in_cluster = unichar_index (wtext, j-1);
 	    }
 	  else
 	    {
@@ -637,7 +653,7 @@ set_up_pango_log_clusters (gboolean rtl,
 	  if (j > 0 && usp_log_clusters[j-1] != usp_log_clusters[j])
 	    {
 	      /* Cluster starts */
-	      first_char_in_cluster = j;
+	      first_char_in_cluster = unichar_index (wtext, j);
 	    }
 	  if (j == itemlen - 1)
 	    {
@@ -753,16 +769,21 @@ itemize_shape_and_place (PangoFont        *font,
       ABC abc;
       int script = items[item].a.eScript;
       int ng;
+      int char_offset;
 
       memset (advances, 0, sizeof (advances));
       memset (offsets, 0, sizeof (offsets));
       memset (&abc, 0, sizeof (abc));
 	  
+      /* Note that itemlen is number of wchar_t's i.e. surrogate pairs
+       * count as two!
+       */
       itemlen = items[item+1].iCharPos - items[item].iCharPos;
+      char_offset = unichar_index (wtext, items[item].iCharPos);
 
 #ifdef BASIC_WIN32_DEBUGGING
       if (pango_win32_debug)
-	printf ("  Item %d: iCharPos=%d eScript=%d (%s) %s%s%s%s%s%s%s chars %d--%d (%d)\n",
+	printf ("  Item %d: iCharPos=%d eScript=%d (%s) %s%s%s%s%s%s%s wchar_t %d--%d (%d)\n",
 		item, items[item].iCharPos, script,
 		lang_name (scripts[script]->langid),
 		scripts[script]->fComplex ? "complex" : "simple",
@@ -801,9 +822,10 @@ itemize_shape_and_place (PangoFont        *font,
       ng = glyphs->num_glyphs;
       pango_glyph_string_set_size (glyphs, ng + nglyphs);
       
-      set_up_pango_log_clusters (items[item].a.fRTL, itemlen, log_clusters,
+      set_up_pango_log_clusters (wtext,
+				 items[item].a.fRTL, itemlen, log_clusters,
 				 nglyphs, glyphs->log_clusters + ng,
-				 items[item].iCharPos);
+				 char_offset);
 
       if ((*script_place) (hdc, &script_cache[script], iglyphs, nglyphs,
 			   visattrs, &items[item].a,
@@ -846,7 +868,7 @@ itemize_shape_and_place (PangoFont        *font,
 #ifdef BASIC_WIN32_DEBUGGING
   if (pango_win32_debug)
     {
-      printf ("  Pango log_clusters (%d), char index:", analysis->level);
+      printf ("  Pango log_clusters (level:%d), char index:", analysis->level);
       for (glyphix = 0; glyphix < glyphs->num_glyphs; glyphix++)
 	printf ("%d ", glyphs->log_clusters[glyphix]);
       printf ("\n");
@@ -917,7 +939,6 @@ text_is_simple (const char *text,
   long wlen;
 
   wtext = (wchar_t *) g_utf8_to_utf16 (text, length, NULL, &wlen, NULL);
-
   if (wtext == NULL)
     return TRUE;
 
@@ -927,7 +948,7 @@ text_is_simple (const char *text,
 
 #ifdef BASIC_WIN32_DEBUGGING
   if (pango_win32_debug)
-    printf ("text_is_simple: %.*s (%ld chars): %s\n",
+    printf ("text_is_simple: %.*s (%ld wchar_t): %s\n",
 	    MIN (length, 10), text, wlen, retval ? "YES" : "NO");
 #endif