Update HB-to-Qt bridging code to deal with latest HB

- add support for hb_font_get_{nominal,variation}_glyph() callback
  introduced in 1.2.3
- add support for hb_get_font_h_extents callback
  introduced in 1.1.3
- do not register dummy callbacks for which HB has a bit faster
  implementation (since 1.1.2)
- mark funcs object immutable for the sake of safety

Change-Id: I05281b01d012aed32030ec7cff41a456b5540179
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

1 files changed, 55 insertions, 62 deletions

diff --git a/src/gui/text/qharfbuzzng.cpp b/src/gui/text/qharfbuzzng.cpp
index 55ef9f0d15..6aca660205 100644
--- a/src/gui/text/qharfbuzzng.cpp
+++ b/src/gui/text/qharfbuzzng.cpp
@@ -422,19 +422,53 @@ hb_unicode_funcs_t *hb_qt_get_unicode_funcs()
 
 // Font routines
 
+#if HB_VERSION_ATLEAST(1, 1, 3)
 static hb_bool_t
-_hb_qt_font_get_glyph(hb_font_t * /*font*/, void *font_data,
-                      hb_codepoint_t unicode, hb_codepoint_t /*variation_selector*/,
-                      hb_codepoint_t *glyph,
-                      void * /*user_data*/)
+_hb_qt_get_font_h_extents(hb_font_t * /*font*/, void *font_data,
+                          hb_font_extents_t *metrics,
+                          void * /*user_data*/)
 {
     QFontEngine *fe = static_cast<QFontEngine *>(font_data);
     Q_ASSERT(fe);
 
-    *glyph = fe->glyphIndex(unicode);
+    metrics->ascender = fe->ascent().value();
+    metrics->descender = fe->descent().value();
+    metrics->line_gap = fe->leading().value();
 
     return true;
 }
+#endif
+
+#if HB_VERSION_ATLEAST(1, 2, 3)
+static hb_bool_t
+_hb_qt_font_get_nominal_glyph(hb_font_t * /*font*/, void *font_data,
+                              hb_codepoint_t unicode,
+                              hb_codepoint_t *glyph,
+                              void * /*user_data*/)
+{
+    QFontEngine *fe = static_cast<QFontEngine *>(font_data);
+    Q_ASSERT(fe);
+
+    *glyph = fe->glyphIndex(unicode);
+
+    return *glyph != 0;
+}
+#endif
+
+static hb_bool_t
+_hb_qt_font_get_variation_glyph(hb_font_t * /*font*/, void *font_data,
+                                hb_codepoint_t unicode, hb_codepoint_t /*variation_selector*/,
+                                hb_codepoint_t *glyph,
+                                void * /*user_data*/)
+{
+    QFontEngine *fe = static_cast<QFontEngine *>(font_data);
+    Q_ASSERT(fe);
+
+    // ### TODO add support for variation selectors
+    *glyph = fe->glyphIndex(unicode);
+
+    return *glyph != 0;
+}
 
 static hb_position_t
 _hb_qt_font_get_glyph_h_advance(hb_font_t *font, void *font_data,
@@ -456,15 +490,7 @@ _hb_qt_font_get_glyph_h_advance(hb_font_t *font, void *font_data,
     return advance.value();
 }
 
-static hb_position_t
-_hb_qt_font_get_glyph_v_advance(hb_font_t * /*font*/, void * /*font_data*/,
-                                hb_codepoint_t /*glyph*/,
-                                void * /*user_data*/)
-{
-    qCritical("hb_qt_font_get_glyph_v_advance: vertical writing isn't supported!");
-    return 0;
-}
-
+#if !HB_VERSION_ATLEAST(1, 1, 2)
 static hb_bool_t
 _hb_qt_font_get_glyph_h_origin(hb_font_t * /*font*/, void * /*font_data*/,
                                hb_codepoint_t /*glyph*/,
@@ -473,16 +499,7 @@ _hb_qt_font_get_glyph_h_origin(hb_font_t * /*font*/, void * /*font_data*/,
 {
     return true; // we always work in the horizontal coordinates
 }
-
-static hb_bool_t
-_hb_qt_font_get_glyph_v_origin(hb_font_t * /*font*/, void * /*font_data*/,
-                               hb_codepoint_t /*glyph*/,
-                               hb_position_t * /*x*/, hb_position_t * /*y*/,
-                               void * /*user_data*/)
-{
-    qCritical("hb_qt_get_glyph_v_origin: vertical writing isn't supported!");
-    return false;
-}
+#endif
 
 static hb_position_t
 _hb_qt_font_get_glyph_h_kerning(hb_font_t *font, void *font_data,
@@ -505,15 +522,6 @@ _hb_qt_font_get_glyph_h_kerning(hb_font_t *font, void *font_data,
     return advance.value();
 }
 
-static hb_position_t
-_hb_qt_font_get_glyph_v_kerning(hb_font_t * /*font*/, void * /*font_data*/,
-                                hb_codepoint_t /*first_glyph*/, hb_codepoint_t /*second_glyph*/,
-                                void * /*user_data*/)
-{
-    qCritical("hb_qt_get_glyph_v_kerning: vertical writing isn't supported!");
-    return 0;
-}
-
 static hb_bool_t
 _hb_qt_font_get_glyph_extents(hb_font_t * /*font*/, void *font_data,
                               hb_codepoint_t glyph,
@@ -554,29 +562,6 @@ _hb_qt_font_get_glyph_contour_point(hb_font_t * /*font*/, void *font_data,
     return false;
 }
 
-static hb_bool_t
-_hb_qt_font_get_glyph_name(hb_font_t * /*font*/, void * /*font_data*/,
-                           hb_codepoint_t /*glyph*/,
-                           char *name, unsigned int size,
-                           void * /*user_data*/)
-{
-    qCritical("hb_qt_font_get_glyph_name: not implemented!");
-    if (size)
-        *name = '\0';
-    return false;
-}
-
-static hb_bool_t
-_hb_qt_font_get_glyph_from_name(hb_font_t * /*font*/, void * /*font_data*/,
-                                const char * /*name*/, int /*len*/,
-                                hb_codepoint_t *glyph,
-                                void * /*user_data*/)
-{
-    qCritical("hb_qt_font_get_glyph_from_name: not implemented!");
-    *glyph = 0;
-    return false;
-}
-
 
 static hb_user_data_key_t _useDesignMetricsKey;
 
@@ -595,17 +580,25 @@ struct _hb_qt_font_funcs_t {
     _hb_qt_font_funcs_t()
     {
         funcs = hb_font_funcs_create();
-        hb_font_funcs_set_glyph_func(funcs, _hb_qt_font_get_glyph, NULL, NULL);
+
+#if HB_VERSION_ATLEAST(1, 1, 3)
+        hb_font_funcs_set_font_h_extents_func(funcs, _hb_qt_get_font_h_extents, NULL, NULL);
+#endif
+#if HB_VERSION_ATLEAST(1, 2, 3)
+        hb_font_funcs_set_nominal_glyph_func(funcs, _hb_qt_font_get_nominal_glyph, NULL, NULL);
+        hb_font_funcs_set_variation_glyph_func(funcs, _hb_qt_font_get_variation_glyph, NULL, NULL);
+#else
+        hb_font_funcs_set_glyph_func(funcs, _hb_qt_font_get_variation_glyph, NULL, NULL);
+#endif
         hb_font_funcs_set_glyph_h_advance_func(funcs, _hb_qt_font_get_glyph_h_advance, NULL, NULL);
-        hb_font_funcs_set_glyph_v_advance_func(funcs, _hb_qt_font_get_glyph_v_advance, NULL, NULL);
+#if !HB_VERSION_ATLEAST(1, 1, 2)
         hb_font_funcs_set_glyph_h_origin_func(funcs, _hb_qt_font_get_glyph_h_origin, NULL, NULL);
-        hb_font_funcs_set_glyph_v_origin_func(funcs, _hb_qt_font_get_glyph_v_origin, NULL, NULL);
+#endif
         hb_font_funcs_set_glyph_h_kerning_func(funcs, _hb_qt_font_get_glyph_h_kerning, NULL, NULL);
-        hb_font_funcs_set_glyph_v_kerning_func(funcs, _hb_qt_font_get_glyph_v_kerning, NULL, NULL);
         hb_font_funcs_set_glyph_extents_func(funcs, _hb_qt_font_get_glyph_extents, NULL, NULL);
         hb_font_funcs_set_glyph_contour_point_func(funcs, _hb_qt_font_get_glyph_contour_point, NULL, NULL);
-        hb_font_funcs_set_glyph_name_func(funcs, _hb_qt_font_get_glyph_name, NULL, NULL);
-        hb_font_funcs_set_glyph_from_name_func(funcs, _hb_qt_font_get_glyph_from_name, NULL, NULL);
+
+        hb_font_funcs_make_immutable(funcs);
     }
     ~_hb_qt_font_funcs_t()
     {