Set the kMultiMaster_FontFlag in DirectWrite.

DirectWrite can now produce system font typefaces which are variations,
so mark these as multiple masters so printing knows what to do.

BUG=chromium:697916

Change-Id: Idf09ebba3c7002a09ff2e4a2dbae13dbce4e79d4
Reviewed-on: https://skia-review.googlesource.com/12101
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Hal Canary <halcanary@google.com>

2 files changed, 64 insertions, 0 deletions

diff --git a/src/ports/SkTypeface_win_dw.cpp b/src/ports/SkTypeface_win_dw.cpp
index 9ff9177012..ae4e3f7105 100644
--- a/src/ports/SkTypeface_win_dw.cpp
+++ b/src/ports/SkTypeface_win_dw.cpp
@@ -18,6 +18,7 @@
 #include "SkDWriteFontFileStream.h"
 #include "SkFontDescriptor.h"
 #include "SkFontStream.h"
+#include "SkOTTable_fvar.h"
 #include "SkOTTable_head.h"
 #include "SkOTTable_hhea.h"
 #include "SkOTTable_OS_2.h"
@@ -376,6 +377,13 @@ SkAdvancedTypefaceMetrics* DWriteFontTypeface::onGetAdvancedTypefaceMetrics(
         return info;
     }
 
+    // There are versions of DirectWrite which support named instances for system variation fonts,
+    // but no means to indicate that such a typeface is a variation.
+    AutoTDWriteTable<SkOTTableFontVariations> fvarTable(fDWriteFontFace.get());
+    if (fvarTable.fExists) {
+        info->fFlags |= SkAdvancedTypefaceMetrics::kMultiMaster_FontFlag;
+    }
+
     //There exist CJK fonts which set the IsFixedPitch and Monospace bits,
     //but have full width, latin half-width, and half-width kana.
     bool fixedWidth = (postTable->isFixedPitch &&
diff --git a/src/sfnt/SkOTTable_fvar.h b/src/sfnt/SkOTTable_fvar.h
new file mode 100644
index 0000000000..5d6ffbe4cc
--- /dev/null
+++ b/src/sfnt/SkOTTable_fvar.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkOTTable_fvar_DEFINED
+#define SkOTTable_fvar_DEFINED
+
+#include "SkEndian.h"
+#include "SkOTTableTypes.h"
+
+#pragma pack(push, 1)
+
+struct SkOTTableFontVariations {
+    static const SK_OT_CHAR TAG0 = 'f';
+    static const SK_OT_CHAR TAG1 = 'v';
+    static const SK_OT_CHAR TAG2 = 'a';
+    static const SK_OT_CHAR TAG3 = 'r';
+    static const SK_OT_ULONG TAG = SkOTTableTAG<SkOTTableFontVariations>::value;
+
+    SK_OT_USHORT majorVersion;
+    SK_OT_USHORT minorVersion;
+    SK_OT_USHORT offsetToAxesArray;
+    SK_OT_USHORT reserved;
+    SK_OT_USHORT axisCount;
+    SK_OT_USHORT axisSize; // Must be 0x0014 in v1.0
+    SK_OT_USHORT instanceCount;
+    SK_OT_USHORT instanceSize; // Must be axisCount * sizeof(Fixed) + (4 | 6)
+
+    struct VariationAxisRecord {
+        SK_OT_ULONG axisTag;
+        SK_OT_Fixed minValue;
+        SK_OT_Fixed defaultValue;
+        SK_OT_Fixed maxValue;
+        SK_OT_USHORT flags; // Must be 0
+        SK_OT_USHORT axisNameID;
+    }; // axes[axisCount];
+
+    template <size_t AxisCount> struct InstanceRecord {
+        SK_OT_USHORT subfamilyNameID;
+        SK_OT_USHORT flags; // Must be 0
+        SK_OT_Fixed coordinates[AxisCount];
+        SK_OT_USHORT postScriptNameID;
+    }; // instances[instanceCount];
+};
+
+#pragma pack(pop)
+
+
+#include <stddef.h>
+static_assert(offsetof(SkOTTableFontVariations, instanceSize) == 14, "SkOTTableFontVariations_instanceSize_not_at_14");
+static_assert(sizeof(SkOTTableFontVariations) == 16, "sizeof_SkOTTableFontVariations_not_16");
+
+#endif