[gtk/wip/fanc999/fontchooser.win32.gtk3: 3/3] [WIP] gtk/gtkfontfeatures.c: Add support for PangoWin32Font->FT_Face

[Chun-wei Fan <fanchunwei src gnome org>]

commit b39e416a8ab84aa5863dcd44b37c675f4fa8e95a
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Wed Dec 26 18:21:02 2018 +0800

    [WIP] gtk/gtkfontfeatures.c: Add support for PangoWin32Font->FT_Face
    
    ...WIP!!!...
    
    This is so that we can turn the LOGFONT that is retrieved from the
    PangoFont so that we can load it with FreeType and feed it to HarfBuzz.
    
    There is ongoing work in Pango to do shaping on all supported platforms
    using HarfBuzz, but since this is GTK+-3.24.x, we will still need to
    support the code path without it as well.

 gtk/gtkfontfeatures.c | 79 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 73 insertions(+), 6 deletions(-)
---
diff --git a/gtk/gtkfontfeatures.c b/gtk/gtkfontfeatures.c
index 4133405527..c4e1e86d5f 100644
--- a/gtk/gtkfontfeatures.c
+++ b/gtk/gtkfontfeatures.c
@@ -33,8 +33,15 @@
 #include "gtkradiobutton.h"
 #include "gtkgesturemultipress.h"
 
-#if defined (HAVE_HARFBUZZ) && defined (HAVE_PANGOFT)
-#include <pango/pangofc-font.h>
+#ifdef HAVE_HARFBUZZ
+
+#ifdef HAVE_PANGOFT
+# include <pango/pangofc-font.h>
+#endif
+#ifdef GDK_WINDOWING_WIN32
+# include <pango/pangowin32.h>
+#endif
+
 #include <hb.h>
 #include <hb-ot.h>
 #include <hb-ft.h>
@@ -85,6 +92,54 @@ axis_remove (gpointer key,
   gtk_widget_destroy (a->spin);
 }
 
+
+
+#ifdef GDK_WINDOWING_WIN32
+static FT_Face
+get_ftface_from_pangowin32_font (PangoFont *font, PangoFontMap *font_map)
+{
+  FT_Face face = NULL;
+  PangoWin32FontCache *cache = NULL;
+  LOGFONTW *logfont;
+  HFONT hfont;
+
+  cache = pango_win32_font_map_get_font_cache (font_map);
+  logfont = pango_win32_font_logfontw (font);
+  hfont = pango_win32_font_cache_loadw (cache, logfont);
+
+  /** TODO!!! */
+
+  pango_win32_font_cache_unload (cache, hfont);
+  g_free (logfont);
+
+  return face;
+}
+
+/* Windows: Determine whether we are using PangoWin32 or PangoFT, if there is PangoFT support */
+# ifdef HAVE_PANGOFT
+#  define FT_FACE_FROM_PANGO_FONT(f,m) \
+          PANGO_IS_FC_FONT(f) ?        \
+          pango_fc_font_lock_face (PANGO_FC_FONT (f)) : \
+          get_ftface_from_pangowin32_font (f, m)
+
+#  define PANGO_FONT_UNLOCK_FACE(f) pango_fc_font_unlock_face(PANGO_FC_FONT(f))
+# else
+#  define FT_FACE_FROM_PANGO_FONT(f,m) get_ftface_from_pangowin32_font (f, m)
+#  define PANGO_FONT_UNLOCK_FACE(f)
+# endif
+
+/* Non-Windows: Just assume we are using PangoFT */
+#elif defined (HAVE_PANGOFT)
+# define FT_FACE_FROM_PANGO_FONT(f,m) pango_fc_font_lock_face (PANGO_FC_FONT (f))
+# define PANGO_FONT_UNLOCK_FACE(f) pango_fc_font_unlock_face(PANGO_FC_FONT(f))
+#endif
+
+static FT_Face
+get_ft_face_from_pango_font (PangoFont *font, PangoFontMap *font_map)
+{
+  return FT_FACE_FROM_PANGO_FONT (font, font_map);
+}
+
 /* OpenType variations */
 
 #define FixedToFloat(f) (((float)(f))/65536.0)
@@ -241,6 +296,7 @@ gtk_font_chooser_widget_update_font_variations (GtkFontChooserWidget *fontchoose
   FT_MM_Var *ft_mm_var;
   FT_Error ret;
   gboolean has_axis = FALSE;
+  PangoFontMap *font_map = NULL;
 
   if (priv->updating_variations)
     return FALSE;
@@ -254,7 +310,12 @@ gtk_font_chooser_widget_update_font_variations (GtkFontChooserWidget *fontchoose
   pango_font = pango_context_load_font (gtk_widget_get_pango_context (GTK_WIDGET (fontchooser)),
                                         priv->font_desc);
 
-  ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font));
+  if (priv->font_map != NULL)
+    font_map = priv->font_map;
+  else
+    font_map = pango_cairo_font_map_get_default ();
+
+  ft_face = get_ft_face_from_pango_font (pango_font, font_map);
 
   ret = FT_Get_MM_Var (ft_face, &ft_mm_var);
   if (ret == 0)
@@ -286,7 +347,7 @@ gtk_font_chooser_widget_update_font_variations (GtkFontChooserWidget *fontchoose
       free (ft_mm_var);
     }
 
-  pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+  PANGO_FONT_UNLOCK_FACE (pango_font);
 
   g_object_unref (pango_font);
 
@@ -775,6 +836,7 @@ gtk_font_chooser_widget_update_font_features (GtkFontChooserWidget *fontchooser)
   int i, j;
   GList *l;
   gboolean has_feature = FALSE;
+  PangoFontMap *font_map = NULL;
 
   for (l = priv->feature_items; l; l = l->next)
     {
@@ -789,7 +851,12 @@ gtk_font_chooser_widget_update_font_features (GtkFontChooserWidget *fontchooser)
   pango_font = pango_context_load_font (gtk_widget_get_pango_context (GTK_WIDGET (fontchooser)),
                                         priv->font_desc);
 
-  ft_face = pango_fc_font_lock_face (PANGO_FC_FONT (pango_font));
+  if (priv->font_map != NULL)
+    font_map = priv->font_map;
+  else
+    font_map = pango_cairo_font_map_get_default ();
+
+  ft_face = get_ft_face_from_pango_font (pango_font, font_map);
 
   hb_font = hb_ft_font_create (ft_face, NULL);
 
@@ -850,7 +917,7 @@ gtk_font_chooser_widget_update_font_features (GtkFontChooserWidget *fontchooser)
       hb_face_destroy (hb_face);
     }
 
-  pango_fc_font_unlock_face (PANGO_FC_FONT (pango_font));
+  PANGO_FONT_UNLOCK_FACE (pango_font);
 
   g_object_unref (pango_font);