Finish the 'glyph 0' work of this morning: PANGO_GLYPH_NULL that I

2006-02-02  Behdad Esfahbod  <behdad@gnome.org>

        Finish the 'glyph 0' work of this morning:
        PANGO_GLYPH_NULL that I introduced is renamed to
        PANGO_GLYPH_EMPTY.  It means, no rendering should
        be performed.  The backends however, still return
        0 if a glyph is not found.  The modules then are
        free to replace this 0 glyph with an unknown
        character.

        * modules/arabic/arabic-fc.c, modules/basic/basic-atsui.c,
        modules/basic/basic-fc.c, modules/basic/basic-win32.c,
        modules/basic/basic-x.c, modules/hangul/hangul-fc.c,
        modules/hebrew/hebrew-fc.c, modules/indic/indic-fc.c,
        modules/khmer/khmer-fc.c, modules/syriac/syriac-fc.c,
        modules/thai/thai-fc.c, modules/tibetan/tibetan-fc.c,
        pango/pangox.c, pango/pangowin32.c:
        Adapt to above change.  Backends return 0 if glyph not
        found.

        * pango/fonts.c (pango_font_get_glyph_extents): If font
        is not usable (!PANGO_IS_FONT (font)), return the generic
        UNKNOWN_GLYPH metrics.  This is used when your backends
        are misconfigured and you don't find *any* font at all.

        * pango/pango-engince.c: Add unknown glyphs in fallback
        shaper, instead of empty glyphs.

        * pango/shape.c: Call the fall-back shaper if shaper
        fails, instead of generating a dummy glyph string ourselves.

        * pango/pango-layout.c (imposed_shape, shape_tab): Use
        PANGO_GLYPH_EMPTY instead of glyph 0.

        * pango/pango-renderer.c (pango_renderer_draw_glyph): No-op on
        PANGO_GLYPH_EMPTY instead of glyph 0.

        * pango/pangocairo-atsuifont.c, pango/pangocairo-win32font.c,
        pango/pangocairo-fcfont.c, pango/pangocairo-font.c,
        pango/pangocairo-private.h: install_font returns a boolean now.

        * pango/pangocairo-render.c, pango/pangoxft-render.c: Handle font
        and hex-box failures more gracefully by drawing a generic
        unknown-box glyph.

        * pango/pangoft2.c, pango/pangoft2-render.c: Draw the generic
        unknown-box glyph here too.  For unknown glyphs though, if
        the font is TTF (FT_IS_SFNT), use the zero-indexed glyph,
        otherwise, draw a box of proper size.

1 files changed, 21 insertions, 20 deletions

diff --git a/pango/pangowin32.c b/pango/pangowin32.c
index 77970285..e3af31c7 100644
--- a/pango/pangowin32.c
+++ b/pango/pangowin32.c
@@ -311,11 +311,12 @@ pango_win32_render (HDC               hdc,
        * point zero (just spacing).
        */
       while (i < glyphs->num_glyphs &&
-	     (glyphs->glyphs[i].glyph == PANGO_GLYPH_NULL || cur_y_offset == glyphs->glyphs[i].geometry.y_offset))
+	     (glyphs->glyphs[i].glyph == PANGO_GLYPH_EMPTY ||
+	      cur_y_offset == glyphs->glyphs[i].geometry.y_offset))
 	{
-	  if (glyphs->glyphs[i].glyph == PANGO_GLYPH_NULL)
+	  if (glyphs->glyphs[i].glyph == PANGO_GLYPH_EMPTY)
 	    {
-	      /* PANGO_GLYPH_NULL glyphs should not be rendered, but their
+	      /* PANGO_GLYPH_EMPTY glyphs should not be rendered, but their
 	       * indicated width (set up by PangoLayout) should be taken
 	       * into account.
 	       */
@@ -460,6 +461,15 @@ pango_win32_font_get_glyph_extents (PangoFont      *font,
   MAT2 m = {{0,1}, {0,0}, {0,0}, {0,1}};
   PangoWin32GlyphInfo *info;
 
+  if (glyph == PANGO_GLYPH_EMPTY)
+    {
+      if (ink_rect)
+	ink_rect->x = ink_rect->width = ink_rect->y = ink_rect->height = 0;
+      if (logical_rect)
+	logical_rect->x = logical_rect->width = logical_rect->y = logical_rect->height = 0;
+      return;
+    }
+
   if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
     glyph_index = glyph = 0;
 
@@ -467,17 +477,7 @@ pango_win32_font_get_glyph_extents (PangoFont      *font,
   
   if (!info)
     {
-      info = g_new (PangoWin32GlyphInfo, 1);
-
-      info->ink_rect.x = 0;
-      info->ink_rect.width = 0;
-      info->ink_rect.y = 0;
-      info->ink_rect.height = 0;
-
-      info->logical_rect.x = 0;
-      info->logical_rect.width = 0;
-      info->logical_rect.y = 0;
-      info->logical_rect.height = 0;
+      info = g_new0 (PangoWin32GlyphInfo, 1);
 
       memset (&gm, 0, sizeof (gm));
 
@@ -1365,7 +1365,8 @@ font_get_cmap (PangoFont *font)
  * @font: a #PangoFont.
  * @wc: a Unicode character.
  *
- * Obtains the index of the glyph for @wc in @font.
+ * Obtains the index of the glyph for @wc in @font, or 0, if not
+ * covered.
  *
  * Return value: the glyph index for @wc.
  **/
@@ -1381,7 +1382,7 @@ pango_win32_font_get_glyph_index (PangoFont *font,
   cmap = font_get_cmap (font);
 
   if (cmap == NULL)
-    return PANGO_GLYPH_NULL;
+    return 0;
 
   if (win32font->win32face->cmap_format == 4)
     {
@@ -1394,10 +1395,10 @@ pango_win32_font_get_glyph_index (PangoFont *font,
       guint16 ch = wc;
   
       if (wc > 0xFFFF)
-	return PANGO_GLYPH_NULL;
+	return 0;
 
       if (!find_segment (cmap4, ch, &segment))
-	return PANGO_GLYPH_NULL;
+	return 0;
 
       id_range_offset = get_id_range_offset (cmap4);
       id_delta = get_id_delta (cmap4);
@@ -1413,7 +1414,7 @@ pango_win32_font_get_glyph_index (PangoFont *font,
 	  if (id)
 	    glyph = (id_delta[segment] + id) %65536;
 	  else
-	    glyph = PANGO_GLYPH_NULL;
+	    glyph = 0;
 	}
     }
   else if (win32font->win32face->cmap_format == 12)
@@ -1421,7 +1422,7 @@ pango_win32_font_get_glyph_index (PangoFont *font,
       struct format_12_cmap *cmap12 = cmap;
       guint32 i;
 
-      glyph = PANGO_GLYPH_NULL;
+      glyph = 0;
       for (i = 0; i < cmap12->count; i++)
 	{
 	  if (cmap12->groups[i*3+0] <= wc && wc <= cmap12->groups[i*3+1])