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, 59 insertions, 27 deletions

diff --git a/pango/pangoft2.c b/pango/pangoft2.c
index 459fa0ab..c20afdf5 100644
--- a/pango/pangoft2.c
+++ b/pango/pangoft2.c
@@ -33,6 +33,8 @@
 #include "pangofc-fontmap.h"
 #include "pangofc-private.h"
 
+PangoFT2WarningHistory _pango_ft2_warning_history = { FALSE };
+
 /* for compatibility with older freetype versions */
 #ifndef FT_LOAD_TARGET_MONO
 #define FT_LOAD_TARGET_MONO  FT_LOAD_MONOCHROME
@@ -58,8 +60,6 @@ static void                   pango_ft2_font_get_glyph_extents (PangoFont      *
 
 static FT_Face    pango_ft2_font_real_lock_face         (PangoFcFont      *font);
 static void       pango_ft2_font_real_unlock_face       (PangoFcFont      *font);
-static PangoGlyph pango_ft2_font_real_get_unknown_glyph (PangoFcFont      *font,
-							 gunichar          wc);
 
 PangoFT2Font *
 _pango_ft2_font_new (PangoFT2FontMap *ft2fontmap,
@@ -173,6 +173,16 @@ pango_ft2_font_get_face (PangoFont *font)
   FcBool antialias, hinting, autohint;
   int id;
 
+  if (G_UNLIKELY (!PANGO_FT2_IS_FONT (font)))
+    {
+      if (!_pango_ft2_warning_history.get_face)
+        {
+	  _pango_ft2_warning_history.get_face = TRUE;
+	  g_critical ("pango_ft2_font_get_face called with bad font, expect ugly output");
+	}
+      return NULL;
+    }
+
   pattern = fcfont->font_pattern;
 
   if (!ft2font->face)
@@ -259,7 +269,6 @@ pango_ft2_font_class_init (PangoFT2FontClass *class)
   
   fc_font_class->lock_face = pango_ft2_font_real_lock_face;
   fc_font_class->unlock_face = pango_ft2_font_real_unlock_face;
-  fc_font_class->get_unknown_glyph = pango_ft2_font_real_get_unknown_glyph;
 }
 
 static PangoFT2GlyphInfo *
@@ -296,25 +305,52 @@ pango_ft2_font_get_glyph_extents (PangoFont      *font,
 {
   PangoFT2GlyphInfo *info;
 
-  if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
-    glyph = PANGO_GLYPH_NULL;
-  if (glyph == PANGO_GLYPH_NULL)
+  if (glyph == PANGO_GLYPH_EMPTY)
     {
       if (ink_rect)
-        {
-	  ink_rect->x = 0;
-	  ink_rect->y = 0;
-	  ink_rect->height = PANGO_UNKNOWN_GLYPH_HEIGHT * PANGO_SCALE;
-	  ink_rect->width = PANGO_UNKNOWN_GLYPH_WIDTH * PANGO_SCALE;
-        }
+	ink_rect->x = ink_rect->y = ink_rect->height = ink_rect->width = 0;
       if (logical_rect)
+	logical_rect->x = logical_rect->y = logical_rect->height = logical_rect->width = 0;
+      return;
+    }
+
+  if (glyph & PANGO_GLYPH_UNKNOWN_FLAG)
+    {
+      FT_Face face = pango_ft2_font_get_face (font);
+      if (face && FT_IS_SFNT (face))
+	glyph = pango_ft2_get_unknown_glyph (font);
+      else
         {
-	  logical_rect->x = 0;
-	  logical_rect->y = 0;
-	  logical_rect->height = PANGO_UNKNOWN_GLYPH_HEIGHT * PANGO_SCALE;
-	  logical_rect->width = PANGO_UNKNOWN_GLYPH_WIDTH * PANGO_SCALE;
+	  PangoFontMetrics *metrics = pango_font_get_metrics (font, NULL);
+
+	  if (metrics)
+	    {
+	      if (ink_rect)
+		{
+		  ink_rect->x = PANGO_SCALE;
+		  ink_rect->y = - (metrics->ascent - PANGO_SCALE);
+		  ink_rect->height = metrics->ascent + metrics->descent - 2 * PANGO_SCALE;
+		  ink_rect->width = metrics->approximate_char_width - 2 * PANGO_SCALE;
+		}
+	      if (logical_rect)
+		{
+		  logical_rect->x = 0;
+		  logical_rect->y = -metrics->ascent;
+		  logical_rect->height = metrics->ascent + metrics->descent;
+		  logical_rect->width = metrics->approximate_char_width;
+		}
+
+	      pango_font_metrics_unref (metrics);
+	    }
+	  else
+	    {
+	      if (ink_rect)
+		ink_rect->x = ink_rect->y = ink_rect->height = ink_rect->width = 0;
+	      if (logical_rect)
+		logical_rect->x = logical_rect->y = logical_rect->height = logical_rect->width = 0;
+	    }
+	  return;
 	}
-      return;
     }
 
   info = pango_ft2_font_get_glyph_info (font, glyph, TRUE);
@@ -381,13 +417,6 @@ pango_ft2_font_real_unlock_face (PangoFcFont *font)
 {
 }
 
-static PangoGlyph
-pango_ft2_font_real_get_unknown_glyph (PangoFcFont *font,
-				       gunichar     wc)
-{
-  return 0;
-}
-
 static gboolean
 pango_ft2_free_glyph_info_callback (gpointer key,
 				    gpointer value,
@@ -505,7 +534,8 @@ _pango_ft2_font_get_cache_glyph_data (PangoFont *font,
 {
   PangoFT2GlyphInfo *info;
 
-  g_return_val_if_fail (PANGO_FT2_IS_FONT (font), NULL);
+  if (!PANGO_FT2_IS_FONT (font))
+    return NULL;
   
   info = pango_ft2_font_get_glyph_info (font, glyph_index, FALSE);
 
@@ -522,7 +552,8 @@ _pango_ft2_font_set_cache_glyph_data (PangoFont     *font,
 {
   PangoFT2GlyphInfo *info;
 
-  g_return_if_fail (PANGO_FT2_IS_FONT (font));
+  if (!PANGO_FT2_IS_FONT (font))
+    return;
   
   info = pango_ft2_font_get_glyph_info (font, glyph_index, TRUE);
 
@@ -535,7 +566,8 @@ void
 _pango_ft2_font_set_glyph_cache_destroy (PangoFont      *font,
 					 GDestroyNotify  destroy_notify)
 {
-  g_return_if_fail (PANGO_FT2_IS_FONT (font));
+  if (!PANGO_FT2_IS_FONT (font))
+    return;
   
   PANGO_FT2_FONT (font)->glyph_cache_destroy = destroy_notify;
 }