Merge branch 'empty-line-height-attr-fix' into 'main'

Fix empty line heights

Closes #421

See merge request GNOME/pango!481

4 files changed, 260 insertions, 39 deletions

diff --git a/pango/pango-layout.c b/pango/pango-layout.c
index 74799ddc..6e761f2c 100644
--- a/pango/pango-layout.c
+++ b/pango/pango-layout.c
@@ -193,6 +193,7 @@ static void pango_layout_get_item_properties (PangoItem      *item,
 static void pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
                                                                 int             index,
                                                                 PangoRectangle *logical_rect,
+                                                                gboolean        apply_line_height,
                                                                 int            *height);
 
 static void pango_layout_finalize    (GObject          *object);
@@ -1908,17 +1909,15 @@ pango_layout_index_to_line_and_extents (PangoLayout     *layout,
           {
             if (run_rect)
               {
-                *run_rect = *line_rect;
-
                 while (TRUE)
                   {
                     PangoLayoutRun *run = _pango_layout_iter_get_run (&iter);
 
-                     if (!run)
-                       break;
-
                     pango_layout_iter_get_run_extents (&iter, NULL, run_rect);
 
+                    if (!run)
+                      break;
+
                     if (run->item->offset <= index && index < run->item->offset + run->item->length)
                       break;
 
@@ -4482,7 +4481,7 @@ pango_layout_check_lines (PangoLayout *layout)
     {
       PangoRectangle logical = { 0, };
       int height = 0;
-      pango_layout_get_empty_extents_and_height_at_index (layout, 0, &logical, &height);
+      pango_layout_get_empty_extents_and_height_at_index (layout, 0, &logical, TRUE, &height);
       state.line_height = layout->line_spacing == 0.0 ? logical.height : layout->line_spacing * height;
     }
 
@@ -5115,6 +5114,7 @@ static void
 pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
                                                     int             index,
                                                     PangoRectangle *logical_rect,
+                                                    gboolean        apply_line_height,
                                                     int             *height)
 {
   if (logical_rect)
@@ -5122,6 +5122,8 @@ pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
       PangoFont *font;
       PangoFontDescription *font_desc = NULL;
       gboolean free_font_desc = FALSE;
+      double line_height_factor = 0.0;
+      int absolute_line_height = 0;
 
       font_desc = pango_context_get_font_description (layout->context);
 
@@ -5147,6 +5149,8 @@ pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
 
               if (start <= index && index < end)
                 {
+                  PangoAttribute *attr;
+
                   if (!free_font_desc)
                     {
                       font_desc = pango_font_description_copy_static (font_desc);
@@ -5158,6 +5162,14 @@ pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
                                                 NULL,
                                                 NULL);
 
+                  attr = pango_attr_iterator_get (&iter, PANGO_ATTR_LINE_HEIGHT);
+                  if (attr)
+                    line_height_factor = ((PangoAttrFloat *)attr)->value;
+
+                  attr = pango_attr_iterator_get (&iter, PANGO_ATTR_ABSOLUTE_LINE_HEIGHT);
+                  if (attr)
+                    absolute_line_height = ((PangoAttrInt *)attr)->value;
+
                   break;
                 }
 
@@ -5183,6 +5195,18 @@ pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
                 *height = pango_font_metrics_get_height (metrics);
 
               pango_font_metrics_unref (metrics);
+
+              if (apply_line_height &&
+                  (absolute_line_height != 0 || line_height_factor != 0.0))
+                {
+                  int line_height, leading;
+
+                  line_height = MAX (absolute_line_height, ceilf (line_height_factor * logical_rect->height));
+
+                  leading = line_height - logical_rect->height;
+                  logical_rect->y -= leading / 2;
+                  logical_rect->height += leading;
+                }
             }
           else
             {
@@ -5206,14 +5230,6 @@ pango_layout_get_empty_extents_and_height_at_index (PangoLayout    *layout,
 }
 
 static void
-pango_layout_line_get_empty_extents_and_height (PangoLayoutLine *line,
-                                                PangoRectangle  *logical_rect,
-                                                int             *height)
-{
-  pango_layout_get_empty_extents_and_height_at_index (line->layout, line->start_index, logical_rect, height);
-}
-
-static void
 pango_layout_run_get_extents_and_height (PangoLayoutRun *run,
                                          PangoRectangle *run_ink,
                                          PangoRectangle *run_logical,
@@ -5347,6 +5363,7 @@ pango_layout_run_get_extents_and_height (PangoLayoutRun *run,
           int line_height, leading;
 
           line_height = MAX (properties.absolute_line_height, ceilf (properties.line_height * line_logical->height));
+
           leading = line_height - line_logical->height;
           line_logical->y -= leading / 2;
           line_logical->height += leading;
@@ -5479,7 +5496,7 @@ pango_layout_line_get_extents_and_height (PangoLayoutLine *line,
       PangoRectangle r, *rect;
 
       rect = logical_rect ? logical_rect : &r;
-      pango_layout_line_get_empty_extents_and_height (line, rect, height);
+      pango_layout_get_empty_extents_and_height_at_index (line->layout, line->start_index, rect, TRUE, height);
     }
 
   if (caching)
@@ -7341,18 +7358,35 @@ pango_layout_iter_get_run_extents (PangoLayoutIter *iter,
     }
   else
     {
-      /* The empty run at the end of a line */
+      if (iter->line->runs)
+        {
+          /* The empty run at the end of a non-empty line */
+          PangoLayoutRun *run = g_slist_last (iter->line->runs)->data;
+          pango_layout_run_get_extents_and_height (run, ink_rect, logical_rect, NULL, NULL);
+        }
+      else
+        {
+          PangoRectangle r;
 
-      pango_layout_iter_get_line_extents (iter, ink_rect, logical_rect);
+          pango_layout_get_empty_extents_and_height_at_index (iter->layout, 0, &r, FALSE, NULL);
+
+          if (ink_rect)
+            *ink_rect = r;
+
+          if (logical_rect)
+            *logical_rect = r;
+        }
 
       if (ink_rect)
         {
+          offset_y (iter, &ink_rect->y);
           ink_rect->x = iter->run_x;
           ink_rect->width = 0;
         }
 
       if (logical_rect)
         {
+          offset_y (iter, &logical_rect->y);
           logical_rect->x = iter->run_x;
           logical_rect->width = 0;
         }
diff --git a/pango/pangocairo-fcfont.c b/pango/pangocairo-fcfont.c
index 0019f83a..85cc45c8 100644
--- a/pango/pangocairo-fcfont.c
+++ b/pango/pangocairo-fcfont.c
@@ -76,8 +76,20 @@ pango_cairo_fc_font_create_base_metrics_for_context (PangoCairoFont *cfont,
 						     PangoContext   *context)
 {
   PangoFcFont *fcfont = (PangoFcFont *) (cfont);
+  PangoFontMetrics *metrics;
+  const cairo_font_options_t *options;
 
-  return pango_fc_font_create_base_metrics_for_context (fcfont, context);
+  metrics = pango_fc_font_create_base_metrics_for_context (fcfont, context);
+
+  options = pango_cairo_context_get_font_options (context);
+  if (cairo_font_options_get_hint_metrics (options) == CAIRO_HINT_METRICS_ON)
+    {
+      metrics->ascent = PANGO_PIXELS_CEIL (metrics->ascent) * PANGO_SCALE;
+      metrics->descent = PANGO_PIXELS_CEIL (metrics->descent) * PANGO_SCALE;
+      metrics->height = PANGO_PIXELS_CEIL (metrics->height) * PANGO_SCALE;
+    }
+
+  return metrics;
 }
 
 static void
diff --git a/pango/pangocairo-font.c b/pango/pangocairo-font.c
index 69c375c3..15c5be4a 100644
--- a/pango/pangocairo-font.c
+++ b/pango/pangocairo-font.c
@@ -784,40 +784,41 @@ struct _PangoCairoFontGlyphExtentsCacheEntry
 static gboolean
 _pango_cairo_font_private_glyph_extents_cache_init (PangoCairoFontPrivate *cf_priv)
 {
-  cairo_scaled_font_t *scaled_font = _pango_cairo_font_private_get_scaled_font (cf_priv);
-  cairo_font_extents_t font_extents;
-
-  if (G_UNLIKELY (scaled_font == NULL || cairo_scaled_font_status (scaled_font) != CAIRO_STATUS_SUCCESS))
-    return FALSE;
-
-  cairo_scaled_font_extents (scaled_font, &font_extents);
+  PangoCairoFont *cfont = cf_priv->cfont;
+  PangoFontMetrics *metrics = _pango_cairo_font_get_metrics (PANGO_FONT (cfont), NULL);
 
   cf_priv->font_extents.x = 0;
   cf_priv->font_extents.width = 0;
-  cf_priv->font_extents.height = pango_units_from_double (font_extents.ascent + font_extents.descent);
+  cf_priv->font_extents.height = metrics->ascent + metrics->descent;
+
   switch (cf_priv->gravity)
     {
       default:
       case PANGO_GRAVITY_AUTO:
       case PANGO_GRAVITY_SOUTH:
-	cf_priv->font_extents.y = - pango_units_from_double (font_extents.ascent);
-	break;
+       cf_priv->font_extents.y = - metrics->ascent;
+       break;
       case PANGO_GRAVITY_NORTH:
-	cf_priv->font_extents.y = - pango_units_from_double (font_extents.descent);
-	break;
+       cf_priv->font_extents.y = - metrics->descent;
+       break;
       case PANGO_GRAVITY_EAST:
       case PANGO_GRAVITY_WEST:
-	{
-	  int ascent = pango_units_from_double (font_extents.ascent + font_extents.descent) / 2;
-	  if (cf_priv->is_hinted)
-	    ascent = PANGO_UNITS_ROUND (ascent);
-	  cf_priv->font_extents.y = - ascent;
-	}
+       {
+         int ascent = (metrics->ascent + metrics->descent) / 2;
+         if (cf_priv->is_hinted)
+           ascent = PANGO_UNITS_ROUND (ascent);
+         cf_priv->font_extents.y = - ascent;
+       }
     }
 
-  cf_priv->glyph_extents_cache = g_new0 (PangoCairoFontGlyphExtentsCacheEntry, GLYPH_CACHE_NUM_ENTRIES);
-  /* Make sure all cache entries are invalid initially */
-  cf_priv->glyph_extents_cache[0].glyph = 1; /* glyph 1 cannot happen in bucket 0 */
+  pango_font_metrics_unref (metrics);
+
+  if (!cf_priv->glyph_extents_cache)
+    {
+      cf_priv->glyph_extents_cache = g_new0 (PangoCairoFontGlyphExtentsCacheEntry, GLYPH_CACHE_NUM_ENTRIES);
+      /* Make sure all cache entries are invalid initially */
+      cf_priv->glyph_extents_cache[0].glyph = 1; /* glyph 1 cannot happen in bucket 0 */
+    }
 
   return TRUE;
 }
diff --git a/tests/testmisc.c b/tests/testmisc.c
index 60694134..b9ec81ea 100644
--- a/tests/testmisc.c
+++ b/tests/testmisc.c
@@ -126,6 +126,134 @@ test_line_height (void)
 }
 
 static void
+test_line_height2 (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoLayoutLine *line;
+  int height1 = 0;
+  int height2 = 0;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  layout = pango_layout_new (context);
+  pango_layout_set_text (layout, "one", -1);
+
+  line = pango_layout_get_line_readonly (layout, 0);
+  pango_layout_line_get_height (line, &height1);
+
+  pango_layout_set_text (layout, "", -1);
+
+  line = pango_layout_get_line_readonly (layout, 0);
+  pango_layout_line_get_height (line, &height2);
+
+  g_assert_cmpint (height1, ==, height2);
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static void
+test_line_height3 (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoLayoutLine *line;
+  PangoAttrList *attrs;
+  int height1 = 0;
+  int height2 = 0;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  layout = pango_layout_new (context);
+  pango_layout_set_text (layout, "one", -1);
+  attrs = pango_attr_list_new ();
+  pango_attr_list_insert (attrs, pango_attr_line_height_new (2.0));
+  pango_layout_set_attributes (layout, attrs);
+  pango_attr_list_unref (attrs);
+
+  line = pango_layout_get_line_readonly (layout, 0);
+  pango_layout_line_get_height (line, &height1);
+
+  pango_layout_set_text (layout, "", -1);
+
+  line = pango_layout_get_line_readonly (layout, 0);
+  pango_layout_line_get_height (line, &height2);
+
+  g_assert_cmpint (height1, ==, height2);
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static void
+test_run_height (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoLayoutIter *iter;
+  PangoRectangle logical1, logical2;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  layout = pango_layout_new (context);
+  pango_layout_set_text (layout, "one", -1);
+
+  iter = pango_layout_get_iter (layout);
+  pango_layout_iter_get_run_extents (iter, NULL, &logical1);
+  pango_layout_iter_free (iter);
+
+  pango_layout_set_text (layout, "", -1);
+
+  iter = pango_layout_get_iter (layout);
+  pango_layout_iter_get_run_extents (iter, NULL, &logical2);
+  pango_layout_iter_free (iter);
+
+  g_assert_cmpint (logical1.height, ==, logical2.height);
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static void
+test_cursor_height (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoRectangle strong;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  layout = pango_layout_new (context);
+  pango_layout_set_text (layout, "one\ttwo", -1);
+  pango_layout_get_cursor_pos (layout, 0, &strong, NULL);
+
+  g_assert_cmpint (strong.height, >, 0);
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static void
+test_cursor_height2 (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoRectangle strong1, strong2;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+  layout = pango_layout_new (context);
+  pango_layout_set_text (layout, "one", -1);
+
+  pango_layout_get_cursor_pos (layout, 0, &strong1, NULL);
+
+  pango_layout_set_text (layout, "", -1);
+
+  pango_layout_get_cursor_pos (layout, 0, &strong2, NULL);
+
+  g_assert_cmpint (strong1.height, ==, strong2.height);
+
+  g_object_unref (layout);
+  g_object_unref (context);
+}
+
+static void
 test_attr_list_update (void)
 {
   PangoAttribute *weight_attr;
@@ -489,6 +617,46 @@ test_extents (void)
   g_object_unref (context);
 }
 
+static void
+test_empty_line_height (void)
+{
+  PangoContext *context;
+  PangoLayout *layout;
+  PangoRectangle ext1, ext2, ext3;
+  cairo_font_options_t *options;
+  int hint;
+
+  context = pango_font_map_create_context (pango_cairo_font_map_get_default ());
+
+  for (hint = CAIRO_HINT_METRICS_OFF; hint <= CAIRO_HINT_METRICS_ON; hint++)
+    {
+      options = cairo_font_options_create ();
+      cairo_font_options_set_hint_metrics (options, hint);
+      pango_cairo_context_set_font_options (context, options);
+      cairo_font_options_destroy (options);
+
+      layout = pango_layout_new (context);
+
+      pango_layout_get_extents (layout, NULL, &ext1);
+
+      pango_layout_set_text (layout, "a", 1);
+
+      pango_layout_get_extents (layout, NULL, &ext2);
+
+      g_assert_cmpint (ext1.height, ==, ext2.height);
+
+      pango_layout_set_text (layout, "Pg", 1);
+
+      pango_layout_get_extents (layout, NULL, &ext3);
+
+      g_assert_cmpint (ext2.height, ==, ext3.height);
+
+      g_object_unref (layout);
+    }
+
+  g_object_unref (context);
+}
+
 int
 main (int argc, char *argv[])
 {
@@ -500,6 +668,11 @@ main (int argc, char *argv[])
   g_test_add_func ("/layout/short-string-crash", test_short_string_crash);
   g_test_add_func ("/language/emoji-crash", test_language_emoji_crash);
   g_test_add_func ("/layout/line-height", test_line_height);
+  g_test_add_func ("/layout/line-height2", test_line_height2);
+  g_test_add_func ("/layout/line-height3", test_line_height3);
+  g_test_add_func ("/layout/run-height", test_run_height);
+  g_test_add_func ("/layout/cursor-height", test_cursor_height);
+  g_test_add_func ("/layout/cursor-height2", test_cursor_height2);
   g_test_add_func ("/attr-list/update", test_attr_list_update);
   g_test_add_func ("/misc/version-info", test_version_info);
   g_test_add_func ("/misc/is-zerowidth", test_is_zero_width);
@@ -514,6 +687,7 @@ main (int argc, char *argv[])
   g_test_add_func ("/bidi/get-cursor", test_get_cursor);
   g_test_add_func ("/layout/index-to-x", test_index_to_x);
   g_test_add_func ("/layout/extents", test_extents);
+  g_test_add_func ("/layout/empty-line-height", test_empty_line_height);
 
   return g_test_run ();
 }