[pango/pango2-windows: 3/5] pango-font.c: Make face_get_blob() a shared function

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

commit 2a97eab3d0cd24710967e1fb746c036bf9981e5e
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Tue Jun 28 12:32:39 2022 +0800

    pango-font.c: Make face_get_blob() a shared function
    
    ...which was in pangocairo-ft-font.c, since we want to use this function for
    DirectWrite as well to create the cairo_font_face_t that we want in the Cairo
    support.
    
    Rename that function as pango2_font_get_hb_blob(), and move it to pango-font.c,
    and place its prototype in pango-font-private.h.  Update the calls in
    pangocairo-ft-font.c accordingly.

 pango2/pango-font-private.h |  26 ++++++-----
 pango2/pango-font.c         | 103 ++++++++++++++++++++++++++++++++++++++++++++
 pango2/pangocairo-ft-font.c |  98 +----------------------------------------
 3 files changed, 120 insertions(+), 107 deletions(-)
---
diff --git a/pango2/pango-font-private.h b/pango2/pango-font-private.h
index ca8d3a775..a0ce1a6bd 100644
--- a/pango2/pango-font-private.h
+++ b/pango2/pango-font-private.h
@@ -29,6 +29,8 @@
 #include <cairo.h>
 #endif
 
+G_BEGIN_DECLS
+
 struct _Pango2Font
 {
   GObject parent_instance;
@@ -107,18 +109,20 @@ pango2_font_set_ctm (Pango2Font         *font,
   font->ctm = ctm ? *ctm : matrix_init;
 }
 
-gboolean pango2_font_is_hinted         (Pango2Font  *font);
-void     pango2_font_get_scale_factors (Pango2Font  *font,
-                                        double      *x_scale,
-                                        double      *y_scale);
-void     pango2_font_get_transform     (Pango2Font  *font,
-                                       Pango2Matrix *matrix);
+gboolean   pango2_font_is_hinted         (Pango2Font  *font);
+void       pango2_font_get_scale_factors (Pango2Font  *font,
+                                          double      *x_scale,
+                                          double      *y_scale);
+void       pango2_font_get_transform     (Pango2Font  *font,
+                                          Pango2Matrix *matrix);
+
+gboolean   pango2_font_description_is_similar       (const Pango2FontDescription *a,
+                                                     const Pango2FontDescription *b);
 
-gboolean pango2_font_description_is_similar       (const Pango2FontDescription *a,
-                                                   const Pango2FontDescription *b);
+int        pango2_font_description_compute_distance (const Pango2FontDescription *a,
+                                                     const Pango2FontDescription *b);
 
-int      pango2_font_description_compute_distance (const Pango2FontDescription *a,
-                                                   const Pango2FontDescription *b);
+hb_blob_t *pango2_font_get_hb_blob                  (Pango2Font *font);
 
 /* We use these values in a few places as a fallback size for an
  * unknown glyph, if we have no better information.
@@ -126,3 +130,5 @@ int      pango2_font_description_compute_distance (const Pango2FontDescription *
 
 #define PANGO2_UNKNOWN_GLYPH_WIDTH  10
 #define PANGO2_UNKNOWN_GLYPH_HEIGHT 14
+
+G_END_DECLS
diff --git a/pango2/pango-font.c b/pango2/pango-font.c
index cdf2fc42c..df8dea5d8 100644
--- a/pango2/pango-font.c
+++ b/pango2/pango-font.c
@@ -246,6 +246,109 @@ pango2_font_get_scale_factors (Pango2Font *font,
   PANGO2_FONT_GET_CLASS (font)->get_scale_factors (font, x_scale, y_scale);
 }
 
+/*< private >
+ * pango2_font_get_hb_blob:
+ * @font: a `Pango2Font`
+ *
+ * Get the font data as a blob. Either, the hb_face_t was
+ * created from a blob to begin with, or we receate one using
+ * hb_face_builder_create(). Unfortunately we can't rely on
+ * hb_face_get_table_tags(), so we just have to list all possible
+ * OpenType tables here and try them all.
+ *
+ * This is not ideal from a memory perspective, but cairo does
+ * not have a scaled font implementation that takes individual
+ * tables.
+ */
+hb_blob_t *
+pango2_font_get_hb_blob (Pango2Font *font)
+{
+  hb_font_t *hb_font;
+  hb_face_t *hb_face;
+  hb_blob_t *blob;
+  hb_face_t *builder;
+  static const hb_tag_t ot_tables[] = {
+    HB_TAG ('a','v','a','r'),
+    HB_TAG ('B','A','S','E'),
+    HB_TAG ('C','B','D','T'),
+    HB_TAG ('C','B','L','C'),
+    HB_TAG ('C','F','F',' '),
+    HB_TAG ('C','F','F','2'),
+    HB_TAG ('c','m','a','p'),
+    HB_TAG ('C','O','L','R'),
+    HB_TAG ('C','P','A','L'),
+    HB_TAG ('c','v','a','r'),
+    HB_TAG ('c','v','t',' '),
+    HB_TAG ('D','S','I','G'),
+    HB_TAG ('E','B','D','T'),
+    HB_TAG ('E','B','L','C'),
+    HB_TAG ('E','B','S','C'),
+    HB_TAG ('f','p','g','m'),
+    HB_TAG ('f','v','a','r'),
+    HB_TAG ('g','a','s','p'),
+    HB_TAG ('G','D','E','F'),
+    HB_TAG ('g','l','y','f'),
+    HB_TAG ('G','P','O','S'),
+    HB_TAG ('G','S','U','B'),
+    HB_TAG ('g','v','a','r'),
+    HB_TAG ('h','d','m','x'),
+    HB_TAG ('h','e','a','d'),
+    HB_TAG ('h','h','e','a'),
+    HB_TAG ('h','m','t','x'),
+    HB_TAG ('H','V','A','R'),
+    HB_TAG ('J','S','T','F'),
+    HB_TAG ('k','e','r','n'),
+    HB_TAG ('l','o','c','a'),
+    HB_TAG ('L','T','S','H'),
+    HB_TAG ('M','A','T','H'),
+    HB_TAG ('m','a','x','p'),
+    HB_TAG ('M','E','R','G'),
+    HB_TAG ('m','e','t','a'),
+    HB_TAG ('M','V','A','R'),
+    HB_TAG ('n','a','m','e'),
+    HB_TAG ('O','S','/','2'),
+    HB_TAG ('P','C','L','T'),
+    HB_TAG ('p','o','s','t'),
+    HB_TAG ('p','r','e','p'),
+    HB_TAG ('s','b','i','x'),
+    HB_TAG ('S','T','A','T'),
+    HB_TAG ('S','V','G',' '),
+    HB_TAG ('V','D','M','X'),
+    HB_TAG ('v','h','e','a'),
+    HB_TAG ('v','m','t','x'),
+    HB_TAG ('V','O','R','G'),
+    HB_TAG ('V','V','A','R'),
+  };
+
+  hb_font = pango2_font_get_hb_font (font);
+  hb_face = hb_font_get_face (hb_font);
+  blob = hb_face_reference_blob (hb_face);
+
+  if (blob != hb_blob_get_empty ())
+    return blob;
+
+  builder = hb_face_builder_create ();
+
+  for (unsigned int i = 0; i < G_N_ELEMENTS (ot_tables); i++)
+    {
+      hb_blob_t *table;
+
+      table = hb_face_reference_table (hb_face, ot_tables[i]);
+
+      if (table != hb_blob_get_empty ())
+        {
+          hb_face_builder_add_table (builder, ot_tables[i], table);
+          hb_blob_destroy (table);
+        }
+    }
+
+  blob = hb_face_reference_blob (builder);
+
+  hb_face_destroy (builder);
+
+  return blob;
+}
+
 /* }}} */
 /* {{{ Public API */
 
diff --git a/pango2/pangocairo-ft-font.c b/pango2/pangocairo-ft-font.c
index d7770ddbe..f5f6c044e 100644
--- a/pango2/pangocairo-ft-font.c
+++ b/pango2/pangocairo-ft-font.c
@@ -32,101 +32,6 @@
 #include <cairo-ft.h>
 #include <freetype/ftmm.h>
 
-/* Get the font data as a blob. Either, the hb_face_t was
- * created from a blob to begin with, or we receate one using
- * hb_face_builder_create(). Unfortunately we can't rely on
- * hb_face_get_table_tags(), so we just have to list all possible
- * OpenType tables here and try them all.
- *
- * This is not ideal from a memory perspective, but cairo does
- * not have a scaled font implementation that takes individual
- * tables.
- */
-static hb_blob_t *
-face_get_blob (hb_face_t *face)
-{
-  hb_blob_t *blob;
-  hb_face_t *builder;
-  static const hb_tag_t ot_tables[] = {
-    HB_TAG ('a','v','a','r'),
-    HB_TAG ('B','A','S','E'),
-    HB_TAG ('C','B','D','T'),
-    HB_TAG ('C','B','L','C'),
-    HB_TAG ('C','F','F',' '),
-    HB_TAG ('C','F','F','2'),
-    HB_TAG ('c','m','a','p'),
-    HB_TAG ('C','O','L','R'),
-    HB_TAG ('C','P','A','L'),
-    HB_TAG ('c','v','a','r'),
-    HB_TAG ('c','v','t',' '),
-    HB_TAG ('D','S','I','G'),
-    HB_TAG ('E','B','D','T'),
-    HB_TAG ('E','B','L','C'),
-    HB_TAG ('E','B','S','C'),
-    HB_TAG ('f','p','g','m'),
-    HB_TAG ('f','v','a','r'),
-    HB_TAG ('g','a','s','p'),
-    HB_TAG ('G','D','E','F'),
-    HB_TAG ('g','l','y','f'),
-    HB_TAG ('G','P','O','S'),
-    HB_TAG ('G','S','U','B'),
-    HB_TAG ('g','v','a','r'),
-    HB_TAG ('h','d','m','x'),
-    HB_TAG ('h','e','a','d'),
-    HB_TAG ('h','h','e','a'),
-    HB_TAG ('h','m','t','x'),
-    HB_TAG ('H','V','A','R'),
-    HB_TAG ('J','S','T','F'),
-    HB_TAG ('k','e','r','n'),
-    HB_TAG ('l','o','c','a'),
-    HB_TAG ('L','T','S','H'),
-    HB_TAG ('M','A','T','H'),
-    HB_TAG ('m','a','x','p'),
-    HB_TAG ('M','E','R','G'),
-    HB_TAG ('m','e','t','a'),
-    HB_TAG ('M','V','A','R'),
-    HB_TAG ('n','a','m','e'),
-    HB_TAG ('O','S','/','2'),
-    HB_TAG ('P','C','L','T'),
-    HB_TAG ('p','o','s','t'),
-    HB_TAG ('p','r','e','p'),
-    HB_TAG ('s','b','i','x'),
-    HB_TAG ('S','T','A','T'),
-    HB_TAG ('S','V','G',' '),
-    HB_TAG ('V','D','M','X'),
-    HB_TAG ('v','h','e','a'),
-    HB_TAG ('v','m','t','x'),
-    HB_TAG ('V','O','R','G'),
-    HB_TAG ('V','V','A','R'),
-  };
-
-  blob = hb_face_reference_blob (face);
-
-  if (blob != hb_blob_get_empty ())
-    return blob;
-
-  builder = hb_face_builder_create ();
-
-  for (unsigned int i = 0; i < G_N_ELEMENTS (ot_tables); i++)
-    {
-      hb_blob_t *table;
-
-      table = hb_face_reference_table (face, ot_tables[i]);
-
-      if (table != hb_blob_get_empty ())
-        {
-          hb_face_builder_add_table (builder, ot_tables[i], table);
-          hb_blob_destroy (table);
-        }
-    }
-
-  blob = hb_face_reference_blob (builder);
-
-  hb_face_destroy (builder);
-
-  return blob;
-}
-
 cairo_font_face_t *
 create_cairo_ft_font_face (Pango2Font *font)
 {
@@ -154,8 +59,7 @@ create_cairo_ft_font_face (Pango2Font *font)
     }
 
   hb_font = pango2_font_get_hb_font (font);
-  hbface = hb_font_get_face (hb_font);
-  blob = face_get_blob (hbface);
+  blob = pango2_font_get_hb_blob (font);
   blob_data = hb_blob_get_data (blob, &blob_length);
 
   if ((error = FT_New_Memory_Face (ft_library,