Initial OpenType Font Variations Support

third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm

 /*
  * This file is part of the internal font implementation.
  *
  * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (c) 2010 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #import "platform/fonts/FontPlatformData.h"
 
 #import "platform/LayoutTestSupport.h"
 #import "platform/fonts/Font.h"
+#import "platform/fonts/opentype/FontSettings.h"
 #import "platform/fonts/shaping/HarfBuzzFace.h"
 #import "platform/graphics/skia/SkiaUtils.h"
 #import "public/platform/Platform.h"
 #import "public/platform/mac/WebSandboxSupport.h"
 #import "third_party/skia/include/ports/SkTypeface_mac.h"
 #import "wtf/RetainPtr.h"
 #import "wtf/text/WTFString.h"
 #import <AppKit/NSFont.h>
 #import <AvailabilityMacros.h>
 
@@ skipping 114 matching lines @@
 
   // When rendering using CoreGraphics, disable hinting when
   // webkit-font-smoothing:antialiased or text-rendering:geometricPrecision is
   // used.  See crbug.com/152304
   if (font &&
       (font->getFontDescription().fontSmoothing() == Antialiased ||
        font->getFontDescription().textRendering() == GeometricPrecision))
     paint->setHinting(SkPaint::kNo_Hinting);
 }
 
+static SkFourByteTag atomicStringToFourByteTag(AtomicString tag) {

[eae, 2016/12/16 18:48:27]

Given that we probably want a couple of checks in here it might make sense to
share this function across implementations.

[drott, 2016/12/19 14:12:34]

Moved to FontSettings.h and cleared of Skia types in order not to pollute our
includes.

+  return SkSetFourByteTag(tag[0], tag[1], tag[2], tag[3]);
+}
+
 FontPlatformData::FontPlatformData(NSFont* nsFont,
                                    float size,
                                    bool syntheticBold,
                                    bool syntheticItalic,
-                                   FontOrientation orientation)
+                                   FontOrientation orientation,
+                                   FontVariationSettings* variationSettings)
     : m_textSize(size),
       m_syntheticBold(syntheticBold),
       m_syntheticItalic(syntheticItalic),
       m_orientation(orientation),
       m_isHashTableDeletedValue(false) {
   DCHECK(nsFont);
   if (canLoadInProcess(nsFont)) {
     m_typeface.reset(SkCreateTypefaceFromCTFont(toCTFontRef(nsFont)));
   } else {
     // In process loading fails for cases where third party font manager
     // software registers fonts in non system locations such as /Library/Fonts
     // and ~/Library Fonts, see crbug.com/72727 or crbug.com/108645.
     m_typeface = loadFromBrowserProcess(nsFont, size);
   }
+
+  if (variationSettings && variationSettings->size() < UINT16_MAX) {
+    SkFontMgr::FontParameters::Axis axes[variationSettings->size()];
+    for (size_t i = 0; i < variationSettings->size(); ++i) {
+      AtomicString featureTag = variationSettings->at(i).tag();
+      axes[i] = {atomicStringToFourByteTag(featureTag),
+                 SkFloatToScalar(variationSettings->at(i).value())};
+    }
+    RefPtr<SkFontMgr> fm = adoptRef(SkFontMgr::RefDefault());
+    // TODO crbug.com/670246: Refactor this to a future Skia API that acccepts
+    // axis parameters on system fonts directly.
+    m_typeface = sk_sp<SkTypeface>(fm->createFromStream(
+        m_typeface->openStream(nullptr)->duplicate(),
+        SkFontMgr::FontParameters().setAxes(axes, variationSettings->size())));
+  }
 }
 
 }  // namespace blink