Fix bundled HarfBuzz-NG build outside QtGui

On Mac, hb_coretext requires both CTFont and CGFont. Due to not supporting the 0 tag by CoreText, hb_blob_get_data() always fails causing the hb_coretext_shaper initialization to fail, too. Since HarfBuzz-NG is not a part of QtGui module anymore, there are two possibilities to workaround this: either engineer the font data by querying tables one-by-one and generating the font directory table, or pass CTFont and CGFont refs directly to hb_coretext via the hb_face's user_data. This patch implements the latter. Change-Id: I7d2e2df00818ea811642cb6a6c3b9c9abd5d7b94 Reviewed-by: Lars Knoll <[email protected]>
qt · Mar 19, 2014 · c6b555d · c6b555d
1 parent 0d50efe
commit c6b555d
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Showing 2 changed files with 45 additions and 32 deletions.
diff --git a/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc b/src/3rdparty/harfbuzz-ng/src/hb-coretext.cc
@@ -32,7 +32,6 @@
 #include "hb-coretext.h"
 
 #include "hb-face-private.hh"
-#include <private/qfontengine_p.h>
 
 
 #ifndef HB_DEBUG_CORETEXT
@@ -44,6 +43,19 @@ HB_SHAPER_DATA_ENSURE_DECLARE(coretext, face)
 HB_SHAPER_DATA_ENSURE_DECLARE(coretext, font)
 
 
+typedef bool (*qt_get_font_table_func_t) (void *user_data, unsigned int tag, unsigned char *buffer, unsigned int *length);
+
+struct FontEngineFaceData {
+  void *user_data;
+  qt_get_font_table_func_t get_font_table;
+};
+
+struct CoreTextFontEngineData {
+  CTFontRef ctFont;
+  CGFontRef cgFont;
+};
+
+
 /*
  * shaper face data
  */
@@ -83,25 +95,11 @@ _hb_coretext_shaper_face_data_create (hb_face_t *face)
   if (unlikely (!data))
     return NULL;
 
-  QFontEngine *fe = (QFontEngine *) ((QFontEngine::FaceData *) face->user_data)->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);
-  if (unlikely (!blob_length))
-    DEBUG_MSG (CORETEXT, face, "Face has empty blob");
-
-  CGDataProviderRef provider = CGDataProviderCreateWithData (blob, blob_data, blob_length, &release_data);
-  data->cg_font = CGFontCreateWithDataProvider (provider);
-  CGDataProviderRelease (provider);
-  }
+  FontEngineFaceData *fontEngineFaceData = (FontEngineFaceData *) face->user_data;
+  CoreTextFontEngineData *coreTextFontEngineData = (CoreTextFontEngineData *) fontEngineFaceData->user_data;
+  data->cg_font = coreTextFontEngineData->cgFont;
+  if (likely (data->cg_font))
+    CFRetain (data->cg_font);
 
   if (unlikely (!data->cg_font)) {
     DEBUG_MSG (CORETEXT, face, "Face CGFontCreateWithDataProvider() failed");
@@ -146,9 +144,13 @@ _hb_coretext_shaper_font_data_create (hb_font_t *font)
     return NULL;
 
   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 / 64, NULL, NULL);
+  FontEngineFaceData *fontEngineFaceData = (FontEngineFaceData *) face->user_data;
+  CoreTextFontEngineData *coreTextFontEngineData = (CoreTextFontEngineData *) fontEngineFaceData->user_data;
+  data->ct_font = coreTextFontEngineData->ctFont;
+  if (likely (data->ct_font))
+    CFRetain (data->ct_font);
+
   if (unlikely (!data->ct_font)) {
     DEBUG_MSG (CORETEXT, font, "Font CTFontCreateWithGraphicsFont() failed");
     free (data);

diff --git a/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm b/src/platformsupport/fontdatabases/mac/qfontengine_coretext.mm
@@ -50,6 +50,22 @@
 
 static float SYNTHETIC_ITALIC_SKEW = tanf(14 * acosf(0) / 90);
 
+static bool ct_getSfntTable(void *user_data, uint tag, uchar *buffer, uint *length)
+{
+    CTFontRef ctfont = *(CTFontRef *)user_data;
+
+    QCFType<CFDataRef> table = CTFontCopyTable(ctfont, tag, 0);
+    if (!table)
+        return false;
+
+    CFIndex tableLength = CFDataGetLength(table);
+    if (buffer && int(*length) >= tableLength)
+        CFDataGetBytes(table, CFRangeMake(0, tableLength), buffer);
+    *length = tableLength;
+    Q_ASSERT(int(*length) > 0);
+    return true;
+}
+
 static void loadAdvancesForGlyphs(CTFontRef ctfont,
                                   QVarLengthArray<CGGlyph> &cgGlyphs,
                                   QGlyphLayout *glyphs, int len,
@@ -191,7 +207,10 @@ int getTraitValue(CFDictionaryRef allTraits, CFStringRef trait)
 
     cache_cost = (CTFontGetAscent(ctfont) + CTFontGetDescent(ctfont)) * avgCharWidth.toInt() * 2000;
 
-    setUserData(QVariant::fromValue((void *)cgFont));
+    // HACK hb_coretext requires both CTFont and CGFont but user_data is only void*
+    Q_ASSERT((void *)(&ctfont + 1) == (void *)&cgFont);
+    faceData.user_data = &ctfont;
+    faceData.get_font_table = ct_getSfntTable;
 }
 
 glyph_t QCoreTextFontEngine::glyphIndex(uint ucs4) const
@@ -683,15 +702,7 @@ static void qcoretextfontengine_scaleMetrics(glyph_metrics_t &br, const QTransfo
 
 bool QCoreTextFontEngine::getSfntTableData(uint tag, uchar *buffer, uint *length) const
 {
-    QCFType<CFDataRef> table = CTFontCopyTable(ctfont, tag, 0);
-    if (!table)
-        return false;
-    CFIndex tableLength = CFDataGetLength(table);
-    if (buffer && int(*length) >= tableLength)
-        CFDataGetBytes(table, CFRangeMake(0, tableLength), buffer);
-    *length = tableLength;
-    Q_ASSERT(int(*length) > 0);
-    return true;
+    return ct_getSfntTable((void *)&ctfont, tag, buffer, length);
 }
 
 void QCoreTextFontEngine::getUnscaledGlyph(glyph_t, QPainterPath *, glyph_metrics_t *)