Bug 342525 – With PangoFc and PangoWin32, approximate digit width is not

2006-05-22  Behdad Esfahbod  <behdad@gnome.org>

        Bug 342525 – With PangoFc and PangoWin32, approximate digit width is
        not what it says

        * pango/pangocairo-win32font.c (max_glyph_width),
        (create_metrics_for_context): Use max digit width instead of average.

        Reverted the following changes:

        * pango/pangofc-font.c (pango_fc_font_create_metrics_for_context):
        Likewise for PangoFc.  Compute average instead of max.
        (max_glpyh_with): Now unused, drop.

        * pango/pangowin32.c (pango_win32_font_get_metrics): Calculate
        average digit width correctly, not as max of the digit
        widths. (#342525) Note that this code doesn't really get much used
        currently (instead the code in pangocairo-win32font.c is used),
        fixed only for completeness.
        (max_glpyh_with): Now unused, drop.

4 files changed, 99 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index fe666f9b..d266d04c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,26 @@
 2006-05-22  Behdad Esfahbod  <behdad@gnome.org>
 
+	Bug 342525 – With PangoFc and PangoWin32, approximate digit width is
+	not what it says
+
+	* pango/pangocairo-win32font.c (max_glyph_width),
+	(create_metrics_for_context): Use max digit width instead of average.
+
+	Reverted the following changes:
+
+	* pango/pangofc-font.c (pango_fc_font_create_metrics_for_context):
+	Likewise for PangoFc.  Compute average instead of max.
+	(max_glpyh_with): Now unused, drop.
+
+	* pango/pangowin32.c (pango_win32_font_get_metrics): Calculate
+	average digit width correctly, not as max of the digit
+	widths. (#342525) Note that this code doesn't really get much used
+	currently (instead the code in pangocairo-win32font.c is used),
+	fixed only for completeness.
+	(max_glpyh_with): Now unused, drop.
+
+2006-05-22  Behdad Esfahbod  <behdad@gnome.org>
+
 	* pango/pango-font.h, pango/fonts.c: New function
 	pango_font_describe_with_absolute_size().
 
diff --git a/pango/pangocairo-win32font.c b/pango/pangocairo-win32font.c
index a7ef250a..53ced191 100644
--- a/pango/pangocairo-win32font.c
+++ b/pango/pangocairo-win32font.c
@@ -268,6 +268,30 @@ pango_cairo_win32_font_get_glyph_extents (PangoFont        *font,
     *logical_rect = info->logical_rect;
 }
 
+static int
+max_glyph_width (PangoLayout *layout)
+{
+  int max_width = 0;
+  GSList *l, *r;
+
+  for (l = pango_layout_get_lines (layout); l; l = l->next)
+    {
+      PangoLayoutLine *line = l->data;
+
+      for (r = line->runs; r; r = r->next)
+        {
+          PangoGlyphString *glyphs = ((PangoGlyphItem *)r->data)->glyphs;
+          int i;
+
+          for (i = 0; i < glyphs->num_glyphs; i++)
+            if (glyphs->glyphs[i].geometry.width > max_width)
+              max_width = glyphs->glyphs[i].geometry.width;
+        }
+    }
+
+  return max_width;
+}
+
 static PangoFontMetrics *
 create_metrics_for_context (PangoFont    *font,
 			    PangoContext *context)
@@ -316,9 +340,7 @@ create_metrics_for_context (PangoFont    *font,
   metrics->approximate_char_width = extents.width / g_utf8_strlen (sample_str, -1);
 
   pango_layout_set_text (layout, "0123456789", -1);
-  pango_layout_get_extents (layout, NULL, &extents);
-
-  metrics->approximate_digit_width = extents.width / 10;
+  metrics->approximate_digit_width = max_glyph_width (layout);
 
   pango_font_description_free (font_desc);
   g_object_unref (layout);
diff --git a/pango/pangofc-font.c b/pango/pangofc-font.c
index da9b9754..b2abb694 100644
--- a/pango/pangofc-font.c
+++ b/pango/pangofc-font.c
@@ -407,6 +407,30 @@ get_face_metrics (PangoFcFont      *fcfont,
   PANGO_FC_FONT_UNLOCK_FACE (fcfont);
 }
 
+static int
+max_glyph_width (PangoLayout *layout)
+{
+  int max_width = 0;
+  GSList *l, *r;
+
+  for (l = pango_layout_get_lines (layout); l; l = l->next)
+    {
+      PangoLayoutLine *line = l->data;
+
+      for (r = line->runs; r; r = r->next)
+        {
+          PangoGlyphString *glyphs = ((PangoGlyphItem *)r->data)->glyphs;
+          int i;
+
+          for (i = 0; i < glyphs->num_glyphs; i++)
+            if (glyphs->glyphs[i].geometry.width > max_width)
+              max_width = glyphs->glyphs[i].geometry.width;
+        }
+    }
+
+  return max_width;
+}
+
 PangoFontMetrics *
 pango_fc_font_create_metrics_for_context (PangoFcFont   *fcfont,
 					  PangoContext  *context)
@@ -428,11 +452,12 @@ pango_fc_font_create_metrics_for_context (PangoFcFont   *fcfont,
   
   pango_layout_set_text (layout, sample_str, -1);      
   pango_layout_get_extents (layout, NULL, &extents);
-  metrics->approximate_char_width = extents.width / g_utf8_strlen (sample_str, -1);
+  
+  metrics->approximate_char_width = 
+    extents.width / g_utf8_strlen (sample_str, -1);
 
   pango_layout_set_text (layout, "0123456789", -1);
-  pango_layout_get_extents (layout, NULL, &extents);
-  metrics->approximate_digit_width = extents.width / 10;
+  metrics->approximate_digit_width = max_glyph_width (layout);
 
   g_object_unref (layout);
 
diff --git a/pango/pangowin32.c b/pango/pangowin32.c
index 37d20be2..7e3a2c00 100644
--- a/pango/pangowin32.c
+++ b/pango/pangowin32.c
@@ -527,6 +527,30 @@ pango_win32_font_get_glyph_extents (PangoFont      *font,
     *logical_rect = info->logical_rect;
 }
 
+static int
+max_glyph_width (PangoLayout *layout)
+{
+  int max_width = 0;
+  GSList *l, *r;
+
+  for (l = pango_layout_get_lines (layout); l; l = l->next)
+    {
+      PangoLayoutLine *line = l->data;
+
+      for (r = line->runs; r; r = r->next)
+        {
+          PangoGlyphString *glyphs = ((PangoGlyphItem *)r->data)->glyphs;
+          int i;
+
+          for (i = 0; i < glyphs->num_glyphs; i++)
+            if (glyphs->glyphs[i].geometry.width > max_width)
+              max_width = glyphs->glyphs[i].geometry.width;
+        }
+    }
+
+  return max_width;
+}
+
 static PangoFontMetrics *
 pango_win32_font_get_metrics (PangoFont     *font,
 			      PangoLanguage *language)
@@ -579,7 +603,6 @@ pango_win32_font_get_metrics (PangoFont     *font,
 	      PangoContext *context;
 	      PangoFontDescription *font_desc;
 	      PangoLayout *layout;
-	      PangoRectangle extents;
 	      
 	      /*  Get the average width of the chars in "0123456789" */
 	      context = pango_win32_get_context ();
@@ -588,9 +611,8 @@ pango_win32_font_get_metrics (PangoFont     *font,
 	      pango_context_set_font_description (context, font_desc);
 	      layout = pango_layout_new (context);
 	      pango_layout_set_text (layout, "0123456789", -1);
-	      pango_layout_get_extents (layout, NULL, &extents);
 
-	      metrics->approximate_digit_width = extents.width / 10;
+	      metrics->approximate_digit_width = max_glyph_width (layout);
 
 	      pango_font_description_free (font_desc);
 	      g_object_unref (layout);