Part of Bug 135683 – Cache glyphstring extents

2006-07-08  Behdad Esfahbod  <behdad@gnome.org>

        Part of Bug 135683 – Cache glyphstring extents

        * docs/pango-sections.txt:
        * docs/tmpl/glyphs.sgml:
        * pango/pango.def:
        * pango/pango-glyph.h:
        * pango/glyphstring.c (pango_glyph_string_get_width): New function.
        Much faster than calling pango_glyph_string_extents and using
        logical_rect.width.

        * pango/pango-renderer.c (add_underline), (add_strikethrough),
        (pango_renderer_draw_layout_line): Use the new function for
        optimization.

8 files changed, 71 insertions, 18 deletions

diff --git a/ChangeLog b/ChangeLog
index d87e0754..18ad502f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,19 @@
+2006-07-08  Behdad Esfahbod  <behdad@gnome.org>
+
+	Part of Bug 135683 – Cache glyphstring extents
+
+	* docs/pango-sections.txt:
+	* docs/tmpl/glyphs.sgml:
+	* pango/pango.def:
+	* pango/pango-glyph.h:
+	* pango/glyphstring.c (pango_glyph_string_get_width): New function.
+	Much faster than calling pango_glyph_string_extents and using
+	logical_rect.width.
+
+	* pango/pango-renderer.c (add_underline), (add_strikethrough),
+	(pango_renderer_draw_layout_line): Use the new function for
+	optimization.
+
 2006-07-07  Behdad Esfahbod  <behdad@gnome.org>
 
 	Bug 344766 – Memory leak in get_ruleset() in modules/basic/basic-fc.c
diff --git a/docs/pango-sections.txt b/docs/pango-sections.txt
index 9911c811..c27f8fd4 100644
--- a/docs/pango-sections.txt
+++ b/docs/pango-sections.txt
@@ -98,6 +98,7 @@ pango_glyph_string_set_size
 pango_glyph_string_free
 pango_glyph_string_extents
 pango_glyph_string_extents_range
+pango_glyph_string_get_width
 pango_glyph_string_index_to_x
 pango_glyph_string_x_to_index
 pango_glyph_string_get_logical_widths
diff --git a/docs/tmpl/glyphs.sgml b/docs/tmpl/glyphs.sgml
index b43cbb6a..8292c688 100644
--- a/docs/tmpl/glyphs.sgml
+++ b/docs/tmpl/glyphs.sgml
@@ -382,6 +382,16 @@ The #GObject type for #PangoGlyphString.
 @logical_rect: 
 
 
+<!-- ##### FUNCTION pango_glyph_string_get_width ##### -->
+<para>
+
+</para>
+
+@glyphs: 
+@font: 
+@Returns: 
+
+
 <!-- ##### FUNCTION pango_glyph_string_index_to_x ##### -->
 <para>
 
diff --git a/pango/fonts.c b/pango/fonts.c
index bbc70106..392da566 100644
--- a/pango/fonts.c
+++ b/pango/fonts.c
@@ -1210,7 +1210,7 @@ pango_font_get_glyph_extents  (PangoFont      *font,
 			       PangoRectangle *ink_rect,
 			       PangoRectangle *logical_rect)
 {
-  if (G_UNLIKELY (!PANGO_IS_FONT (font)))
+  if (G_UNLIKELY (!font))
     {
       
       if (!_pango_warning_history.get_glyph_extents)
diff --git a/pango/glyphstring.c b/pango/glyphstring.c
index c4c5c8cd..82770349 100644
--- a/pango/glyphstring.c
+++ b/pango/glyphstring.c
@@ -264,6 +264,33 @@ pango_glyph_string_extents (PangoGlyphString *glyphs,
 }
 
 /**
+ * pango_glyph_string_get_width:
+ * @glyphs:   a #PangoGlyphString
+ * @font:     a #PangoFont
+ * 
+ * Computes the logical width of the glyph string as can also be computed
+ * using pango_glyph_string_extents().  However, since this only computes the
+ * width, it's much faster.  This is in fact only a convenience function that
+ * computes the sum of geometry.width for each glyph in the @glyphs.
+ *
+ * Return value: the logical width of the glyph string.
+ *
+ * Since: 1.14
+ */
+int
+pango_glyph_string_get_width (PangoGlyphString *glyphs,
+			      PangoFont        *font)
+{
+  int i;
+  int width = 0;
+
+  for (i = 0; i < glyphs->num_glyphs; i++)
+    width += &glyphs->glyphs[i].geometry.width;
+
+  return width;
+}
+
+/**
  * pango_glyph_string_get_logical_widths:
  * @glyphs: a #PangoGlyphString
  * @text: the text corresponding to the glyphs
diff --git a/pango/pango-glyph.h b/pango/pango-glyph.h
index 1195f135..71b6911e 100644
--- a/pango/pango-glyph.h
+++ b/pango/pango-glyph.h
@@ -91,6 +91,8 @@ void              pango_glyph_string_extents  (PangoGlyphString *glyphs,
 					       PangoFont        *font,
 					       PangoRectangle   *ink_rect,
 					       PangoRectangle   *logical_rect);
+int               pango_glyph_string_get_width(PangoGlyphString *glyphs,
+					       PangoFont        *font);
 
 void              pango_glyph_string_extents_range  (PangoGlyphString *glyphs,
                                                      int               start,
diff --git a/pango/pango-renderer.c b/pango/pango-renderer.c
index 7f26a950..4c96972a 100644
--- a/pango/pango-renderer.c
+++ b/pango/pango-renderer.c
@@ -289,8 +289,7 @@ add_underline (PangoRenderer    *renderer,
 	       PangoFontMetrics *metrics,
 	       int               base_x,
 	       int               base_y,
-	       PangoRectangle   *ink_rect,
-	       PangoRectangle   *logical_rect)
+	       PangoRectangle   *ink_rect)
 {
   PangoRectangle *current_rect = &state->underline_rect;
   PangoRectangle new_rect;
@@ -341,8 +340,7 @@ add_strikethrough (PangoRenderer    *renderer,
 		   PangoFontMetrics *metrics,
 		   int               base_x,
 		   int               base_y,
-		   PangoRectangle   *ink_rect,
-		   PangoRectangle   *logical_rect)
+		   PangoRectangle   *ink_rect)
 {
   PangoRectangle *current_rect = &state->strikethrough_rect;
   PangoRectangle new_rect;
@@ -450,6 +448,7 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
 				 int               y)
 {
   int x_off = 0;
+  int glyph_string_width;
   LineState state;
   GSList *l;
   gboolean got_overall = FALSE;
@@ -480,7 +479,6 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
       gint rise;
       PangoLayoutRun *run = l->data;
       PangoAttrShape *shape_attr;
-      PangoRectangle logical_rect;
       PangoRectangle ink_rect;
 
       pango_renderer_prepare_run (renderer, run);
@@ -490,20 +488,18 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
       if (shape_attr)
 	{
 	  ink_rect = shape_attr->ink_rect;
-	  logical_rect = shape_attr->logical_rect;
+	  glyph_string_width = shape_attr->logical_rect.width;
 	}
       else
 	{
 	  if (renderer->underline != PANGO_UNDERLINE_NONE ||
 	      renderer->strikethrough)
-	    pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
-					&ink_rect, &logical_rect);
-	  else
-	    pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
-					NULL, &logical_rect);
+	      pango_glyph_string_extents (run->glyphs, run->item->analysis.font,
+					  &ink_rect, NULL);
+	  glyph_string_width = pango_glyph_string_get_width (run->glyphs, run->item->analysis.font);
 	}
 
-      state.logical_rect_end = x + x_off + logical_rect.x + logical_rect.width;
+      state.logical_rect_end = x + x_off + glyph_string_width;
 
       if (renderer->priv->color_set[PANGO_RENDER_PART_BACKGROUND])
 	{
@@ -515,9 +511,9 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
 	  
 	  pango_renderer_draw_rectangle (renderer,
 					 PANGO_RENDER_PART_BACKGROUND,
-					 x + x_off + logical_rect.x,
+					 x + x_off,
 					 y - rise + overall_rect.y,
-					 logical_rect.width,
+					 glyph_string_width,
 					 overall_rect.height);
 	}
 
@@ -541,12 +537,12 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
 	  if (renderer->underline != PANGO_UNDERLINE_NONE)
 	    add_underline (renderer, &state,metrics,
 			   x + x_off, y - rise,
-			   &ink_rect, &logical_rect);
+			   &ink_rect);
 	  
 	  if (renderer->strikethrough)
 	    add_strikethrough (renderer, &state, metrics,
 			       x + x_off, y - rise,
-			       &ink_rect, &logical_rect);
+			       &ink_rect);
 	  
 	  pango_font_metrics_unref (metrics);
 	}
@@ -558,7 +554,7 @@ pango_renderer_draw_layout_line (PangoRenderer    *renderer,
       if (!renderer->strikethrough && state.strikethrough)
 	draw_strikethrough (renderer, &state);
 
-      x_off += logical_rect.width;
+      x_off += glyph_string_width;
     }
 
   /* Finish off any remaining underlines
diff --git a/pango/pango.def b/pango/pango.def
index 4733905e..bb1a7e60 100644
--- a/pango/pango.def
+++ b/pango/pango.def
@@ -172,6 +172,7 @@ EXPORTS
 	pango_glyph_string_free
 	pango_glyph_string_get_logical_widths
 	pango_glyph_string_get_type
+	pango_glyph_string_get_width
 	pango_glyph_string_index_to_x
 	pango_glyph_string_new
 	pango_glyph_string_set_size