Draw the unknown glyph box with X primitives rather than hoping that some

Sun Dec  8 22:57:55 2002  Owen Taylor  <otaylor@redhat.com>

        * pango/pangox.c: Draw the unknown glyph box with
        X primitives rather than hoping that some font has an
        actualpainting unknown glyph... that code was
        apparently still working badly. Use "en" not
        NULL as the language tags for getting the metrics
        for the return glyph and the unknown character
        glyph... NULL gives too large results. (#98245,
        Based on a patch from Morten Welinder.)

1 files changed, 86 insertions, 85 deletions

diff --git a/pango/pangox.c b/pango/pangox.c
index cca2e278..a05fa7f1 100644
--- a/pango/pangox.c
+++ b/pango/pangox.c
@@ -508,9 +508,12 @@ pango_x_render  (Display           *display,
 	      
       if (glyph & PANGO_X_UNKNOWN_FLAG)
         {
-          PangoFontMetrics *metrics = pango_font_get_metrics (font, NULL);
+	  PangoFontMetrics *metrics = pango_font_get_metrics (font,
+							      pango_language_from_string ("en"));
           int x1, y1, x2, y2; /* rectangle the character should go inside. */
           int baseline;
+	  int stroke_thick;
+
           gunichar wc;
           
           x1 = glyph_x;
@@ -518,6 +521,7 @@ pango_x_render  (Display           *display,
           x2 = x1 + PANGO_PIXELS (glyphs->glyphs[i].geometry.width);
           y2 = y1 + PANGO_PIXELS (metrics->ascent + metrics->descent);
           baseline = glyph_y;
+	  stroke_thick = MAX ((int) (0.5 + 0.075 * (y2 - y1)), 1);
           
           wc = glyph & (~PANGO_X_UNKNOWN_FLAG);
 
@@ -532,7 +536,6 @@ pango_x_render  (Display           *display,
                 PangoRectangle up_stroke;
                 PangoRectangle across_stroke;
 
-		int stroke_thick = MAX ((y2 - y1) * 0.075, 1);
 		int hborder = (x2 - x1) * 0.1;
 		int arrow_height = 0.25 * (y2 - y1);
 		int top_border = (y2 - y1) * 0.25;
@@ -578,15 +581,40 @@ pango_x_render  (Display           *display,
               break;
 
             default:
-
-              /* Here we should draw the box-with-numbers as in the
-               * Xft backend. The shaper never gives us a glyph that
-               * activates this case at the moment though, so also
-               * needs hacking.
-               */
-              
-              break;
-            }
+	      {
+		/* Perhaps we should draw the box-with-numbers as in the
+		 * Xft backend, though we have no guarantee of having
+		 * an appropriate size of font. Right now, we just
+		 * draw an empty box. (To draw the box-with-numbers.
+		 * the backends would have to be changed to use
+		 * pango_x_font_get_unknown_glyph() rather than
+		 * pango_x_get_unknown_glyph().
+		 */
+
+		int xspace = MAX ((int) (0.5 + 0.1 * (x2 - x1)), 1);
+		int yspace = MAX ((int) (0.5 + 0.1 * (y2 - y1)), 1);
+
+		x1 += xspace;
+		x2 -= xspace;
+		y1 += yspace;
+		y2 -= yspace;
+
+		XFillRectangle (display, d, gc,
+				x1, y1,
+				x2 - x1, stroke_thick);
+		XFillRectangle (display, d, gc,
+				x1, y1 + stroke_thick,
+				stroke_thick, y2 - y1 - 2 * stroke_thick);
+		XFillRectangle (display, d, gc,
+				x2 - stroke_thick, y1 + stroke_thick,
+				stroke_thick, y2 - y1 - 2 * stroke_thick);
+		XFillRectangle (display, d, gc,
+				x1, y2 - stroke_thick,
+				x2 - x1, stroke_thick);
+		
+		break;
+	      }
+	    }
 
 	  pango_font_metrics_unref (metrics);
         }
@@ -636,7 +664,11 @@ pango_x_font_get_glyph_extents  (PangoFont      *font,
 
   if (glyph & PANGO_X_UNKNOWN_FLAG)
     {
+      PangoFontMetrics *metrics = pango_font_get_metrics (font,
+							  pango_language_from_string ("en"));
       gunichar wc;
+      gdouble width_factor;
+      int w;
       
       wc = glyph & (~PANGO_X_UNKNOWN_FLAG);
           
@@ -647,37 +679,37 @@ pango_x_font_get_glyph_extents  (PangoFont      *font,
         case 0x2028: /* Line separator */
         case 0x2029: /* Paragraph separator */
           {
-            /* Size of carriage-return thingy */
-            PangoFontMetrics *metrics = pango_font_get_metrics (font, NULL);
-            int w;
+#define MAGIC_FACTOR 1.2
 
-#define MAGIC_FACTOR 1.75
-            
-            w = metrics->approximate_char_width * MAGIC_FACTOR;
+            /* carriage-return thingy */
+	    width_factor = MAGIC_FACTOR;
+	    break;
+	  }
+	default:
+	  {
+	    /* Unknown glyph square */
+	    width_factor = 0.7;
+	  }
+	}
+	    
+      w = metrics->approximate_char_width * width_factor;
+      w = PANGO_SCALE * PANGO_PIXELS (w);
             
-            if (ink_rect)
-              {
-                ink_rect->x = 0;
-                ink_rect->width = w;
-                ink_rect->y = - metrics->ascent;
-                ink_rect->height = metrics->ascent + metrics->descent;
-              }
-            if (logical_rect)
-              {
-                logical_rect->x = 0;
-                logical_rect->width = w;
-                logical_rect->y = - metrics->ascent;
-                logical_rect->height = metrics->ascent + metrics->descent;
-              }
-
-	    pango_font_metrics_unref (metrics);
-          }
-          break;
-          
-        default:
-              
-          break;
-        }
+      if (ink_rect)
+	{
+	  ink_rect->x = 0;
+	  ink_rect->width = w;
+	  ink_rect->y = - metrics->ascent;
+	  ink_rect->height = metrics->ascent + metrics->descent;
+	}
+      if (logical_rect)
+	{
+	  logical_rect->x = 0;
+	  logical_rect->width = w;
+	  logical_rect->y = - metrics->ascent;
+	  logical_rect->height = metrics->ascent + metrics->descent;
+	}
+      
     }
   else if (glyph && pango_x_find_glyph (font, glyph, &subfont, &cs))
     {
@@ -912,10 +944,14 @@ get_subfonts_foreach (PangoFont      *font,
 		      gpointer        data)
 {
   GSList **subfonts = data;
+  PangoGlyph glyph = glyph_info->glyph;
 
-  PangoXSubfont subfont = PANGO_X_GLYPH_SUBFONT (glyph_info->glyph);
-  if (!g_slist_find (*subfonts, GUINT_TO_POINTER ((guint)subfont)))
-    *subfonts = g_slist_prepend (*subfonts, GUINT_TO_POINTER ((guint)subfont));
+  if ((glyph & PANGO_X_UNKNOWN_FLAG) == 0)
+    {
+      PangoXSubfont subfont = PANGO_X_GLYPH_SUBFONT (glyph);
+      if (!g_slist_find (*subfonts, GUINT_TO_POINTER ((guint)subfont)))
+	*subfonts = g_slist_prepend (*subfonts, GUINT_TO_POINTER ((guint)subfont));
+    }
 }
 
 /* Get composite font metrics for all subfonts resulting from shaping
@@ -1475,42 +1511,18 @@ pango_x_find_glyph (PangoFont *font,
  * pango_x_get_unknown_glyph:
  * @font: a #PangoFont.
  * 
- * Returns the index of a glyph suitable for drawing unknown characters.
+ * Returns the index of a glyph suitable for drawing unknown characters;
+ * you should generally use pango_x_font_get_unknown_glyph_instead,
+ * since that may return a glyph that provides a better representation
+ * of a particular char. (E.g., by showing hex digits, or a glyph
+ * representive of a certain Unicode range.)
  * 
  * Return value: a glyph index into @font.
  **/
 PangoGlyph
 pango_x_get_unknown_glyph (PangoFont *font)
 {
-  PangoXFont *xfont = (PangoXFont *)font;
-  
-  /* The strategy here is to find _a_ X font, any X font in the fontset, and
-   * then get the unknown glyph for that font.
-   */
-
-  g_return_val_if_fail (font != 0, 0);
-  g_return_val_if_fail (xfont->n_fonts != 0, 0);
-
-  if (xfont->n_subfonts == 0)
-    {
-      int count;
-      char **names = XListFonts (xfont->display, xfont->fonts[0], 1, &count);
-
-      if (count > 0)
-	pango_x_insert_subfont (font, names[0]);
-
-      XFreeFontNames (names);
-    }
-
-  if (xfont->n_subfonts > 0)
-    {
-      XFontStruct *font_struct = pango_x_get_font_struct (font, xfont->subfonts[0]);
-
-      if (font_struct)
-	return PANGO_X_MAKE_GLYPH (1,font_struct->default_char);
-    }
-
-  return 0;
+  return PANGO_X_UNKNOWN_FLAG;
 }
 
 /**
@@ -2175,16 +2187,5 @@ pango_x_font_get_unknown_glyph (PangoFont *font,
 {
   g_return_val_if_fail (PANGO_IS_FONT (font), 0);
 
-  switch (wc)
-    {
-    case '\n':
-    case '\r':
-    case 0x2028: /* Line separator */
-    case 0x2029: /* Paragraph separator */
-      return PANGO_X_UNKNOWN_FLAG | wc;
-      break;
-    default:
-      return 0;
-      break;
-    }
+  return PANGO_X_UNKNOWN_FLAG | wc;
 }