Merge branch 'bring-back-better-rounding' into 'master'

shape: Bring back careful rounding code

Closes #562

See merge request GNOME/pango!344

1 files changed, 73 insertions, 4 deletions

diff --git a/pango/shape.c b/pango/shape.c
index 04407732..b870ecad 100644
--- a/pango/shape.c
+++ b/pango/shape.c
@@ -151,6 +151,32 @@ fallback_shape (const char          *text,
     pango_glyph_string_reverse_range (glyphs, 0, glyphs->num_glyphs);
 }
 
+/* FIXME: This is very ugly. We are out of room for vfuncs, so we can't
+ * easily add api to get is_hinted and the matrix from the PangoFcFont.
+ *
+ * Keep in sync with pangofc-font.h!
+ */
+struct _PangoFcFont
+{
+  PangoFont parent_instance;
+
+  gpointer font_pattern;          /* fully resolved pattern */
+  PangoFontMap *fontmap;            /* associated map */
+  gpointer priv;                    /* used internally */
+  PangoMatrix matrix;               /* used internally */
+  PangoFontDescription *description;
+
+  GSList *metrics_by_lang;
+
+  guint is_hinted : 1;
+  guint is_transformed : 1;
+};
+typedef struct _PangoFcFont PangoFcFont;
+
+#define PANGO_IS_FC_FONT(obj) \
+  g_type_is_a (((GTypeInstance*)obj)->g_class->g_type, \
+               g_type_from_name ("PangoFcFont"))
+
 /**
  * pango_shape_with_flags:
  * @item_text: valid UTF-8 text to shape
@@ -294,11 +320,54 @@ pango_shape_with_flags (const gchar         *item_text,
 
   if (flags & PANGO_SHAPE_ROUND_POSITIONS)
     {
-      for (i = 0; i < glyphs->num_glyphs; i++)
+      if (PANGO_IS_FC_FONT (analysis->font))
         {
-          glyphs->glyphs[i].geometry.width    = PANGO_UNITS_ROUND (glyphs->glyphs[i].geometry.width );
-          glyphs->glyphs[i].geometry.x_offset = PANGO_UNITS_ROUND (glyphs->glyphs[i].geometry.x_offset);
-          glyphs->glyphs[i].geometry.y_offset = PANGO_UNITS_ROUND (glyphs->glyphs[i].geometry.y_offset);
+          PangoFcFont *fc_font = (PangoFcFont *)analysis->font;
+          if (fc_font->is_hinted)
+            {
+              double x_scale_inv, y_scale_inv;
+              double x_scale, y_scale;
+
+              x_scale_inv = y_scale_inv = 1.0;
+              pango_matrix_get_font_scale_factors (&fc_font->matrix, &x_scale_inv, &y_scale_inv);
+              if (PANGO_GRAVITY_IS_IMPROPER (analysis->gravity))
+                {
+                  x_scale_inv = -x_scale_inv;
+                  y_scale_inv = -y_scale_inv;
+                }
+              x_scale = 1. / x_scale_inv;
+              y_scale = 1. / y_scale_inv;
+
+              if (x_scale == 1.0 && y_scale == 1.0)
+                {
+                  for (i = 0; i < glyphs->num_glyphs; i++)
+                    glyphs->glyphs[i].geometry.width = PANGO_UNITS_ROUND (glyphs->glyphs[i].geometry.width);
+                }
+              else
+                {
+    #if 0
+                  if (PANGO_GRAVITY_IS_VERTICAL (analysis->gravity))
+                    {
+                      /* XXX */
+                      double tmp = x_scale;
+                      x_scale = y_scale;
+                      y_scale = -tmp;
+                    }
+    #endif
+    #define HINT(value, scale_inv, scale) (PANGO_UNITS_ROUND ((int) ((value) * scale)) * scale_inv)
+    #define HINT_X(value) HINT ((value), x_scale, x_scale_inv)
+    #define HINT_Y(value) HINT ((value), y_scale, y_scale_inv)
+                  for (i = 0; i < glyphs->num_glyphs; i++)
+                    {
+                      glyphs->glyphs[i].geometry.width    = HINT_X (glyphs->glyphs[i].geometry.width);
+                      glyphs->glyphs[i].geometry.x_offset = HINT_X (glyphs->glyphs[i].geometry.x_offset);
+                      glyphs->glyphs[i].geometry.y_offset = HINT_Y (glyphs->glyphs[i].geometry.y_offset);
+                    }
+    #undef HINT_Y
+    #undef HINT_X
+    #undef HINT
+                }
+            }
         }
     }
 }