[DirectWrite] Consider font fallback when determining aliasing

Source/platform/fonts/win/FontCacheSkiaWin.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Computer, Inc.
  * Copyright (c) 2006, 2007, 2008, 2009, 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 52 matching lines @@
 {
     SkPaint paint;
     fontData->setupPaint(&paint);
     paint.setTextEncoding(SkPaint::kUTF32_TextEncoding);
 
     uint16_t glyph;
     paint.textToGlyphs(&character, sizeof(character), &glyph);
     return glyph;
 }
 
+// Minimum size, in pixels, at which anti alias is enabled for certain
+// scripts. Only applies to the Direct Write backend for now.
+static unsigned minSizeForAntiAlias(UScriptCode script)
+{
+    switch (script) {
+    case USCRIPT_TRADITIONAL_HAN:
+        return 24;
+    case USCRIPT_SIMPLIFIED_HAN:
+    case USCRIPT_HIRAGANA:
+    case USCRIPT_KATAKANA:
+    case USCRIPT_KATAKANA_OR_HIRAGANA:
+    case USCRIPT_HANGUL:
+    case USCRIPT_BENGALI:
+        return 16;
+    case USCRIPT_THAI:
+    case USCRIPT_HEBREW:
+    case USCRIPT_ARABIC:
+    case USCRIPT_DEVANAGARI:
+    case USCRIPT_GURMUKHI:
+    case USCRIPT_GUJARATI:
+    case USCRIPT_TAMIL:
+    case USCRIPT_TELUGU:
+    case USCRIPT_KANNADA:
+    case USCRIPT_GEORGIAN:
+    case USCRIPT_ARMENIAN:
+    case USCRIPT_THAANA:
+    case USCRIPT_CANADIAN_ABORIGINAL:
+    case USCRIPT_CHEROKEE:
+    case USCRIPT_MONGOLIAN:
+    default:
+        return 0;
+    }
+}
+
+static bool fontRequiresFullHinting(const AtomicString& familyName)
+{
+    DEFINE_STATIC_LOCAL(AtomicString, courierNew, ("Courier New", AtomicString::ConstructFromLiteral));
+    if (equalIgnoringCase(familyName, courierNew))
+        return true;
+
+    return false;
+}
+
 // Given the desired base font, this will create a SimpleFontData for a specific
 // font that can be used to render the given range of characters.
 PassRefPtr<SimpleFontData> FontCache::platformFallbackForCharacter(const FontDescription& fontDescription, UChar32 character, const SimpleFontData*)
 {
     // FIXME: Consider passing fontDescription.dominantScript()
     // to GetFallbackFamily here.
     UScriptCode script;
     const wchar_t* family = getFallbackFamily(character,
         fontDescription.genericFamily(),
         &script);
@@ skipping 59 matching lines @@
     for (i = 0; (!data || !fontContainsCharacter(data, family, character)) && i < numFonts; ++i) {
         family = panUniFonts[i];
         data = getFontPlatformData(fontDescription, AtomicString(family, wcslen(family)));
     }
 
     // When i-th font (0-base) in |panUniFonts| contains a character and
     // we get out of the loop, |i| will be |i + 1|. That is, if only the
     // last font in the array covers the character, |i| will be numFonts.
     // So, we have to use '<=" rather than '<' to see if we found a font
     // covering the character.
-    if (i <= numFonts)
+    if (i <= numFonts) {
+        if (s_useDirectWrite)
+            data->setMinSizeForAntiAlias(minSizeForAntiAlias(script));
         return fontDataFromFontPlatformData(data, DoNotRetain);
+    }
 
     return nullptr;
 }
 
 static inline bool equalIgnoringCase(const AtomicString& a, const SkString& b)
 {
     return equalIgnoringCase(a, AtomicString::fromUTF8(b.c_str()));
 }
 
 static bool typefacesMatchesFamily(const SkTypeface* tf, const AtomicString& family)
@@ skipping 16 matching lines @@
     if (!matchesRequestedFamily) {
         SkString familyName;
         tf->getFamilyName(&familyName);
         if (equalIgnoringCase(family, familyName))
             matchesRequestedFamily = true;
     }
 
     return matchesRequestedFamily;
 }
 
-// Minimum size, in pixels, at which anti alias is enabled for certain
-// scripts. Only applies to the Direct Write backend for now.
-static unsigned minSizeForAntiAlias(UScriptCode script)
-{
-    switch (script) {
-    case USCRIPT_TRADITIONAL_HAN:
-        return 24;
-    case USCRIPT_SIMPLIFIED_HAN:
-    case USCRIPT_HIRAGANA:
-    case USCRIPT_KATAKANA:
-    case USCRIPT_KATAKANA_OR_HIRAGANA:
-    case USCRIPT_HANGUL:
-    case USCRIPT_BENGALI:
-        return 16;
-    case USCRIPT_THAI:
-    case USCRIPT_HEBREW:
-    case USCRIPT_ARABIC:
-    case USCRIPT_DEVANAGARI:
-    case USCRIPT_GURMUKHI:
-    case USCRIPT_GUJARATI:
-    case USCRIPT_TAMIL:
-    case USCRIPT_TELUGU:
-    case USCRIPT_KANNADA:
-    case USCRIPT_GEORGIAN:
-    case USCRIPT_ARMENIAN:
-    case USCRIPT_THAANA:
-    case USCRIPT_CANADIAN_ABORIGINAL:
-    case USCRIPT_CHEROKEE:
-    case USCRIPT_MONGOLIAN:
-    default:
-        return 0;
-    }
-}
-
-static bool fontRequiresFullHinting(const AtomicString& familyName)
-{
-    DEFINE_STATIC_LOCAL(AtomicString, courierNew, ("Courier New", AtomicString::ConstructFromLiteral));
-    if (equalIgnoringCase(familyName, courierNew))
-        return true;
-
-    return false;
-}
-
 FontPlatformData* FontCache::createFontPlatformData(const FontDescription& fontDescription, const AtomicString& family, float fontSize)
 {
     CString name;
     RefPtr<SkTypeface> tf = createTypeface(fontDescription, family, name);
     if (!tf)
         return 0;
 
     // Windows will always give us a valid pointer here, even if the face name
     // is non-existent. We have to double-check and see if the family name was
     // really used.
@@ skipping 17 matching lines @@
         result->setMinSizeForAntiAlias(
             minSizeForAntiAlias(fontDescription.script()));
         if (fontRequiresFullHinting(family))
             result->setHinting(SkPaint::kFull_Hinting);
     }
 
     return result;
 }
 
 }