Initial OpenType Font Variations Support

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

Index: third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm
diff --git a/third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm b/third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm
index 27a754ddbf36f18ad235eea62e32adda3205eda3..e1f88c4660ad0ad27e223cc7f3574b027834bb77 100644
--- a/third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm
+++ b/third_party/WebKit/Source/platform/fonts/mac/FontPlatformDataMac.mm
@@ -25,6 +25,7 @@
 
 #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"
@@ -159,11 +160,16 @@ void FontPlatformData::setupPaint(SkPaint* paint,
     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),
@@ -178,6 +184,21 @@ FontPlatformData::FontPlatformData(NSFont* nsFont,
     // 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