Font variations.

Multiple Master and TrueType fonts support variation axes.
This implements back-end support for axes on platforms which
support it.

Committed: https://skia.googlesource.com/skia/+/05773ed30920c0214d1433c07cf6360a05476c97

Committed: https://skia.googlesource.com/skia/+/3489ee0f4fa34f124f9de090d12bdc2107d52aa9

Review URL: https://codereview.chromium.org/1027373002

2 files changed, 27 insertions, 0 deletions

diff --git a/include/core/SkTypeface.h b/include/core/SkTypeface.h
index 7d8b892f2c..f0059deb25 100644
--- a/include/core/SkTypeface.h
+++ b/include/core/SkTypeface.h
@@ -17,6 +17,7 @@
 #include "SkWeakRefCnt.h"
 
 class SkDescriptor;
+class SkFontData;
 class SkFontDescriptor;
 class SkScalerContext;
 struct SkScalerContextRec;
@@ -134,6 +135,12 @@ public:
     */
     static SkTypeface* CreateFromStream(SkStreamAsset* stream, int index = 0);
 
+    /** Return a new typeface given font data and configuration. If the data
+        is not valid font data, returns null. Ownership of the font data is
+        transferred, so the caller must not reference it again.
+    */
+    static SkTypeface* CreateFromFontData(SkFontData*);
+
     /** Write a unique signature to a stream, sufficient to reconstruct a
         typeface referencing the same font when Deserialize is called.
      */
@@ -284,6 +291,12 @@ public:
     SkStreamAsset* openStream(int* ttcIndex) const;
 
     /**
+     *  Return the font data, or NULL on failure.
+     *  The caller is responsible for deleting the font data.
+     */
+    SkFontData* createFontData() const;
+
+    /**
      *  Return a scalercontext for the given descriptor. If this fails, then
      *  if allowFailure is true, this returns NULL, else it returns a
      *  dummy scalercontext that will not crash, but will draw nothing.
@@ -337,6 +350,9 @@ protected:
                         uint32_t glyphIDsCount) const = 0;
 
     virtual SkStreamAsset* onOpenStream(int* ttcIndex) const = 0;
+    // TODO: make pure virtual.
+    virtual SkFontData* onCreateFontData() const;
+
     virtual void onGetFontDescriptor(SkFontDescriptor*, bool* isLocal) const = 0;
 
     virtual int onCharsToGlyphs(const void* chars, Encoding, uint16_t glyphs[],
diff --git a/include/ports/SkFontMgr.h b/include/ports/SkFontMgr.h
index 4dde920085..48a0494a7a 100644
--- a/include/ports/SkFontMgr.h
+++ b/include/ports/SkFontMgr.h
@@ -12,6 +12,7 @@
 #include "SkFontStyle.h"
 
 class SkData;
+class SkFontData;
 class SkStreamAsset;
 class SkString;
 class SkTypeface;
@@ -95,6 +96,14 @@ public:
     SkTypeface* createFromStream(SkStreamAsset*, int ttcIndex = 0) const;
 
     /**
+     *  Create a typeface from the specified font data.
+     *  Takes ownership of the font data, so the caller should not reference it again.
+     *  Will return NULL if the typeface could not be created.
+     *  The caller must call unref() on the returned object if it is not null.
+     */
+    SkTypeface* createFromFontData(SkFontData*) const;
+
+    /**
      *  Create a typeface for the specified fileName and TTC index
      *  (pass 0 for none) or NULL if the file is not found, or its contents are
      *  not recognized. The caller must call unref() on the returned object
@@ -129,6 +138,8 @@ protected:
 
     virtual SkTypeface* onCreateFromData(SkData*, int ttcIndex) const = 0;
     virtual SkTypeface* onCreateFromStream(SkStreamAsset*, int ttcIndex) const = 0;
+    // TODO: make pure virtual.
+    virtual SkTypeface* onCreateFromFontData(SkFontData*) const;
     virtual SkTypeface* onCreateFromFile(const char path[], int ttcIndex) const = 0;
 
     virtual SkTypeface* onLegacyCreateTypeface(const char familyName[],