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, 10 insertions, 26 deletions

diff --git a/pango/shape.c b/pango/shape.c
index 50a083a3..29c28998 100644
--- a/pango/shape.c
+++ b/pango/shape.c
@@ -46,7 +46,7 @@ pango_shape (const gchar      *text,
   int i;
   int last_cluster = -1;
 
-  if (G_LIKELY (analysis->shape_engine && analysis->font))
+  if (G_LIKELY (PANGO_IS_ENGINE_SHAPE (analysis->shape_engine) && PANGO_IS_FONT (analysis->font)))
     {
       _pango_engine_shape_shape (analysis->shape_engine, analysis->font,
 				 text, length, analysis, glyphs);
@@ -84,15 +84,17 @@ pango_shape (const gchar      *text,
     }
   else
     {
-      if (!analysis->shape_engine && !_pango_warning_history.shape_shape_engine)
+      if (!PANGO_IS_ENGINE_SHAPE (analysis->shape_engine) &&
+	  !_pango_warning_history.shape_shape_engine)
         {
 	  _pango_warning_history.shape_font = TRUE;
-	  g_critical ("pango_shape called with analysis->shape_engine == NULL, expect ugly output");
+	  g_critical ("pango_shape called with bad shape_engine, expect ugly output");
 	}
-      if (!analysis->font && !_pango_warning_history.shape_font)
+      if (!PANGO_IS_FONT (analysis->font) &&
+	  !_pango_warning_history.shape_font)
         {
 	  _pango_warning_history.shape_font = TRUE;
-	  g_critical ("pango_shape called with analysis->font == NULL, expect ugly output");
+	  g_critical ("pango_shape called with bad font, expect ugly output");
 	}
 
       glyphs->num_glyphs = 0;
@@ -100,28 +102,10 @@ pango_shape (const gchar      *text,
 
   if (!glyphs->num_glyphs)
     {
-      /* If failed to get glyphs, put unknown glyphs for all characters
-       */
-      const char *p = text;
-      pango_glyph_string_set_size (glyphs, g_utf8_strlen (text, length));
+      PangoEngineShape *fallback_engine = _pango_get_fallback_shaper ();
 
-      for (i = 0; i < glyphs->num_glyphs; i++)
-        {
-	  PangoRectangle logical_rect;
-	  PangoGlyph glyph = g_utf8_get_char (p) | PANGO_GLYPH_UNKNOWN_FLAG;
-	  
-	  pango_font_get_glyph_extents (analysis->font, glyph, NULL, &logical_rect);
-
-	  glyphs->glyphs[i].glyph = glyph;
-	  
-	  glyphs->glyphs[i].geometry.x_offset = 0;
-	  glyphs->glyphs[i].geometry.y_offset = 0;
-	  glyphs->glyphs[i].geometry.width = logical_rect.width;
-	  
-	  glyphs->log_clusters[i] = i;
-
-	  p = g_utf8_next_char (p);
-	}
+      _pango_engine_shape_shape (fallback_engine, analysis->font,
+				 text, length, analysis, glyphs);
     }
 
   /* Set glyphs[i].attr.is_cluster_start based on log_clusters[]