Make HarBuzz-NG the default shaper on Mac

Since we dropped all platform-related shapers during the
QPA refactoring, thus making HarfBuzz the only shaper on all
platforms, we can not deal with AAT-capable fonts anymore.
HarBuzz-NG now supports it's own shaper backend infrastructure,
so the decision was to enable HB's CoreText shaper backend on Mac
and simply make HB-NG the default shaper there.

Task-number: QTBUG-36056

Change-Id: If22e24fd5cc00c25952934332a2f4123f38135a4
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>

configure

@@ -5471,6 +5471,7 @@ fi
 
 # harfbuzz support
 [ "$XPLATFORM_MINGW" = "yes" ] && [ "$CFG_HARFBUZZ" = "auto" ] && CFG_HARFBUZZ=no
+[ "$XPLATFORM_MAC" = "yes" ] && [ "$CFG_HARFBUZZ" = "auto" ] && CFG_HARFBUZZ=yes
 if [ "$CFG_HARFBUZZ" = "auto" ]; then
     if compileTest unix/harfbuzz "HarfBuzz"; then
         CFG_HARFBUZZ=system
@@ -5478,6 +5479,11 @@ if [ "$CFG_HARFBUZZ" = "auto" ]; then
         CFG_HARFBUZZ=yes
     fi
 fi
+if [ "$XPLATFORM_MAC" = "yes" -a "$CFG_HARFBUZZ" = "system" ]; then
+    echo
+    echo "WARNING: AAT is not supported with -system-harfbuzz on Mac OS X."
+    echo
+fi
 
 if ! compileTest unix/stl "STL" &&
     [ "$CFG_CONFIGURE_EXIT_ON_ERROR" = "yes" ]; then

src/3rdparty/harfbuzz-ng/src/hb-coretext.cc

@@ -31,6 +31,9 @@
 
 #include "hb-coretext.h"
 
+#include "hb-face-private.hh"
+#include <private/qfontengine_p.h>
+
 
 #ifndef HB_DEBUG_CORETEXT
 #define HB_DEBUG_CORETEXT (HB_DEBUG+0)
@@ -61,10 +64,34 @@ release_data (void *info, const void *data, size_t size)
 hb_coretext_shaper_face_data_t *
 _hb_coretext_shaper_face_data_create (hb_face_t *face)
 {
+  hb_blob_t *mort_blob = face->reference_table (HB_CORETEXT_TAG_MORT);
+  /* Umm, we just reference the table to check whether it exists.
+   * Maybe add better API for this? */
+  if (!hb_blob_get_length (mort_blob))
+  {
+    hb_blob_destroy (mort_blob);
+    mort_blob = face->reference_table (HB_CORETEXT_TAG_MORX);
+    if (!hb_blob_get_length (mort_blob))
+    {
+      hb_blob_destroy (mort_blob);
+      return NULL;
+    }
+  }
+  hb_blob_destroy (mort_blob);
+
   hb_coretext_shaper_face_data_t *data = (hb_coretext_shaper_face_data_t *) calloc (1, sizeof (hb_coretext_shaper_face_data_t));
   if (unlikely (!data))
     return NULL;
 
+  QFontEngine *fe = (QFontEngine *) face->user_data;
+  if (fe->type () == QFontEngine::Mac)
+  {
+    data->cg_font = (CGFontRef) fe->userData ().value<void *> ();
+    if (likely (data->cg_font))
+      CFRetain (data->cg_font);
+  }
+  else
+  {
   hb_blob_t *blob = hb_face_reference_blob (face);
   unsigned int blob_length;
   const char *blob_data = hb_blob_get_data (blob, &blob_length);
@@ -74,6 +101,7 @@ _hb_coretext_shaper_face_data_create (hb_face_t *face)
   CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
   data->cg_font = CGFontCreateWithDataProvider (provider);
   CGDataProviderRelease (provider);
+  }
 
   if (unlikely (!data->cg_font)) {
     DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
@@ -120,7 +148,7 @@ _hb_coretext_shaper_font_data_create (hb_font_t *font)
   hb_face_t *face = font->face;
   hb_coretext_shaper_face_data_t *face_data = HB_SHAPER_DATA_GET (face);
 
-  data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale, NULL, NULL);
+  data->ct_font = CTFontCreateWithGraphicsFont (face_data->cg_font, font->y_scale / 64, NULL, NULL);
   if (unlikely (!data->ct_font)) {
     DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
     free (data);
@@ -691,7 +719,7 @@ _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
 	     * hb-uniscribe.cc for example. */
             info->cluster = j;
 
-            info->mask = advance;
+            info->mask = advance * 64;
             info->var1.u32 = 0;
             info->var2.u32 = 0;
 
@@ -747,9 +775,9 @@ _hb_coretext_shape (hb_shape_plan_t    *shape_plan,
       info->cluster = string_indices[j];
 
       /* Currently, we do all x-positioning by setting the advance, we never use x-offset. */
-      info->mask = advance;
+      info->mask = advance * 64;
       info->var1.u32 = 0;
-      info->var2.u32 = positions[j].y;
+      info->var2.u32 = positions[j].y * 64;
 
       buffer->len++;
     }

src/3rdparty/harfbuzz-ng/src/hb-coretext.h

@@ -34,6 +34,10 @@
 HB_BEGIN_DECLS
 
 
+#define HB_CORETEXT_TAG_MORT HB_TAG('m','o','r','t')
+#define HB_CORETEXT_TAG_MORX HB_TAG('m','o','r','x')
+
+
 CGFontRef
 hb_coretext_face_get_cg_font (hb_face_t *face);
 

src/3rdparty/harfbuzz-ng/src/hb-shaper-list.hh

@@ -35,6 +35,11 @@
 HB_SHAPER_IMPLEMENT (graphite2)
 #endif
 
+#ifdef HAVE_CORETEXT
+/* Only picks up fonts that have a "mort" or "morx" table. */
+HB_SHAPER_IMPLEMENT (coretext)
+#endif
+
 #ifdef HAVE_OT
 HB_SHAPER_IMPLEMENT (ot) /* <--- This is our main OpenType shaper. */
 #endif
@@ -48,9 +53,6 @@ HB_SHAPER_IMPLEMENT (icu_le)
 #ifdef HAVE_UNISCRIBE
 HB_SHAPER_IMPLEMENT (uniscribe)
 #endif
-#ifdef HAVE_CORETEXT
-HB_SHAPER_IMPLEMENT (coretext)
-#endif
 
 #ifdef HAVE_FALLBACK
 HB_SHAPER_IMPLEMENT (fallback) /* <--- This should be last. */

src/gui/text/qharfbuzzng.cpp

@@ -698,7 +698,7 @@ _hb_qt_font_create(QFontEngine *fe)
     const int x_ppem = (fe->fontDef.pixelSize * fe->fontDef.stretch) / 100;
 
     hb_font_set_funcs(font, hb_qt_get_font_funcs(), (void *)fe, NULL);
-    hb_font_set_scale(font, QFixed(x_ppem).value(), -QFixed(y_ppem).value());
+    hb_font_set_scale(font, QFixed(x_ppem).value(), QFixed(y_ppem).value());
     hb_font_set_ppem(font, x_ppem, y_ppem);
 
     return font;

src/gui/text/qtextengine.cpp

@@ -1195,6 +1195,13 @@ int QTextEngine::shapeTextWithHarfbuzzNG(const QScriptItem &si, const ushort *st
                 g.glyphs[i] |= (engineIdx << 24);
         }
 
+#ifdef Q_OS_MAC
+        if (actualFontEngine->fontDef.styleStrategy & QFont::ForceIntegerMetrics) {
+            for (uint i = 0; i < num_glyphs; ++i)
+                g.advances[i] = g.advances[i].round();
+        }
+#endif
+
         glyphs_shaped += num_glyphs;
     }
 

src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm

@@ -188,6 +188,8 @@ void QCoreTextFontEngine::init()
         avgCharWidth = QFontEngine::averageCharWidth();
 
     cache_cost = (CTFontGetAscent(ctfont) + CTFontGetDescent(ctfont)) * avgCharWidth.toInt() * 2000;
+
+    setUserData(QVariant::fromValue((void *)cgFont));
 }
 
 bool QCoreTextFontEngine::stringToCMap(const QChar *str, int len, QGlyphLayout *glyphs,