[pango: 2/4] Calculate hinted font height based on the hinted extents

[Matthias Clasen <matthiasc src gnome org>]

commit 303f79e14047d60c3ca41c24931c8cb6115433ae
Author: Sebastian Keller <skeller gnome org>
Date:   Mon Nov 22 01:54:15 2021 +0100

    Calculate hinted font height based on the hinted extents
    
    The previous code was calculating the rounded up version of the
    difference between the unhinted ascender and uninted descender. This
    however would only result in the correct height if both unhinted
    extentss together only differ by less then an a Pango unit from their
    hinted counterparts. Otherwise the resulting height would be 1 unit too
    short.
    
    Fix this by using the difference between the hinted extents as height.
    
    Fixes: https://gitlab.gnome.org/GNOME/pango/-/issues/626

 pango/pangocairo-font.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/pango/pangocairo-font.c b/pango/pangocairo-font.c
index fb36d294..c2bcc51b 100644
--- a/pango/pangocairo-font.c
+++ b/pango/pangocairo-font.c
@@ -821,9 +821,9 @@ _pango_cairo_font_private_glyph_extents_cache_init (PangoCairoFontPrivate *cf_pr
       else
         cf_priv->font_extents.y = PANGO_UNITS_CEIL (cf_priv->font_extents.y);
       if (cf_priv->font_extents.height < 0)
-        cf_priv->font_extents.height = PANGO_UNITS_FLOOR (cf_priv->font_extents.height);
+        cf_priv->font_extents.height = PANGO_UNITS_FLOOR (extents.ascender) - PANGO_UNITS_CEIL 
(extents.descender);
       else
-        cf_priv->font_extents.height = PANGO_UNITS_CEIL (cf_priv->font_extents.height);
+        cf_priv->font_extents.height = PANGO_UNITS_CEIL (extents.ascender) - PANGO_UNITS_FLOOR 
(extents.descender);
     }
 
   if (PANGO_GRAVITY_IS_IMPROPER (cf_priv->gravity))