backout changeset 48b74ab18f92 (bug 1018034) due to MS Sans Serif regression with Thai system locale (see bug 1020826).

gfx/thebes/gfxFT2Fonts.cpp

@@ -65,7 +65,7 @@ gfxFT2Font::ShapeText(gfxContext      *aContext,
         }
     }
 
-    if (!ok) {
+    if (!ok && gfxPlatform::GetPlatform()->UseHarfBuzzForScript(aScript)) {
         if (!mHarfBuzzShaper) {
             mHarfBuzzShaper = new gfxHarfBuzzShaper(this);
         }

gfx/thebes/gfxFont.cpp

@@ -3974,8 +3974,10 @@ gfxFont::ShapeText(gfxContext      *aContext,
     }
 
     if (!ok && mHarfBuzzShaper && !aPreferPlatformShaping) {
-        ok = mHarfBuzzShaper->ShapeText(aContext, aText, aOffset, aLength,
+        if (gfxPlatform::GetPlatform()->UseHarfBuzzForScript(aScript)) {
-                                        aScript, aShapedText);
+            ok = mHarfBuzzShaper->ShapeText(aContext, aText, aOffset, aLength,
+                                            aScript, aShapedText);
+        }
     }
 
     if (!ok) {

gfx/thebes/gfxPlatform.cpp

@@ -143,6 +143,8 @@ NS_IMPL_ISUPPORTS(SRGBOverrideObserver, nsIObserver, nsISupportsWeakReference)
 
 #define GFX_DOWNLOADABLE_FONTS_ENABLED "gfx.downloadable_fonts.enabled"
 
+#define GFX_PREF_HARFBUZZ_SCRIPTS "gfx.font_rendering.harfbuzz.scripts"
+#define HARFBUZZ_SCRIPTS_DEFAULT  mozilla::unicode::SHAPING_DEFAULT
 #define GFX_PREF_FALLBACK_USE_CMAPS  "gfx.font_rendering.fallback.always_use_cmaps"
 
 #define GFX_PREF_OPENTYPE_SVG "gfx.font_rendering.opentype_svg.enabled"
@@ -260,6 +262,7 @@ gfxPlatform::gfxPlatform()
   : mAzureCanvasBackendCollector(MOZ_THIS_IN_INITIALIZER_LIST(),
                                  &gfxPlatform::GetAzureBackendInfo)
 {
+    mUseHarfBuzzScripts = UNINITIALIZED_VALUE;
     mAllowDownloadableFonts = UNINITIALIZED_VALUE;
     mFallbackUsesCmaps = UNINITIALIZED_VALUE;
 
@@ -1110,6 +1113,18 @@ gfxPlatform::UseGraphiteShaping()
     return mGraphiteShapingEnabled;
 }
 
+bool
+gfxPlatform::UseHarfBuzzForScript(int32_t aScriptCode)
+{
+    if (mUseHarfBuzzScripts == UNINITIALIZED_VALUE) {
+        mUseHarfBuzzScripts = Preferences::GetInt(GFX_PREF_HARFBUZZ_SCRIPTS, HARFBUZZ_SCRIPTS_DEFAULT);
+    }
+
+    int32_t shapingType = mozilla::unicode::ScriptShapingType(aScriptCode);
+
+    return (mUseHarfBuzzScripts & shapingType) != 0;
+}
+
 gfxFontEntry*
 gfxPlatform::MakePlatformFont(const gfxProxyFontEntry *aProxyEntry,
                               const uint8_t *aFontData,
@@ -1846,6 +1861,9 @@ gfxPlatform::FontsPrefsChanged(const char *aPref)
     } else if (!strcmp(GFX_PREF_GRAPHITE_SHAPING, aPref)) {
         mGraphiteShapingEnabled = UNINITIALIZED_VALUE;
         FlushFontAndWordCaches();
+    } else if (!strcmp(GFX_PREF_HARFBUZZ_SCRIPTS, aPref)) {
+        mUseHarfBuzzScripts = UNINITIALIZED_VALUE;
+        FlushFontAndWordCaches();
     } else if (!strcmp(BIDI_NUMERAL_PREF, aPref)) {
         mBidiNumeralOption = UNINITIALIZED_VALUE;
     } else if (!strcmp(GFX_PREF_OPENTYPE_SVG, aPref)) {

gfx/thebes/gfxPlatform.h

@@ -385,6 +385,13 @@ public:
      */
     bool UseGraphiteShaping();
 
+    /**
+     * Whether to use the harfbuzz shaper (depending on script complexity).
+     *
+     * This allows harfbuzz to be enabled selectively via the preferences.
+     */
+    bool UseHarfBuzzForScript(int32_t aScriptCode);
+
     // check whether format is supported on a platform or not (if unclear, returns true)
     virtual bool IsFontFormatSupported(nsIURI *aFontURI, uint32_t aFormatFlags) { return false; }
 
@@ -612,6 +619,9 @@ protected:
     // when doing system font fallback
     int8_t  mFallbackUsesCmaps;
 
+    // which scripts should be shaped with harfbuzz
+    int32_t mUseHarfBuzzScripts;
+
     // max character limit for words in word cache
     int32_t mWordCacheCharLimit;
 

intl/unicharutil/util/nsUnicodeProperties.cpp

@@ -249,6 +249,64 @@ IsClusterExtender(uint32_t aCh, uint8_t aCategory)
             (aCh >= 0xff9e && aCh <= 0xff9f));  // katakana sound marks
 }
 
+// TODO: replace this with a properties file or similar;
+// expect this to evolve as harfbuzz shaping support matures.
+//
+// The "shaping type" of each script run, as returned by this
+// function, is compared to the bits set in the
+// gfx.font_rendering.harfbuzz.scripts
+// preference to decide whether to use the harfbuzz shaper.
+//
+int32_t
+ScriptShapingType(int32_t aScriptCode)
+{
+    switch (aScriptCode) {
+    default:
+        return SHAPING_DEFAULT; // scripts not explicitly listed here are
+                                // assumed to just use default shaping
+
+    case MOZ_SCRIPT_ARABIC:
+    case MOZ_SCRIPT_SYRIAC:
+    case MOZ_SCRIPT_NKO:
+    case MOZ_SCRIPT_MANDAIC:
+        return SHAPING_ARABIC; // bidi scripts with Arabic-style shaping
+
+    case MOZ_SCRIPT_HEBREW:
+        return SHAPING_HEBREW;
+
+    case MOZ_SCRIPT_HANGUL:
+        return SHAPING_HANGUL;
+
+    case MOZ_SCRIPT_MONGOLIAN: // to be supported by the Arabic shaper?
+        return SHAPING_MONGOLIAN;
+
+    case MOZ_SCRIPT_THAI: // no complex OT features, but MS engines like to do
+                          // sequence checking
+        return SHAPING_THAI;
+
+    case MOZ_SCRIPT_BENGALI:
+    case MOZ_SCRIPT_DEVANAGARI:
+    case MOZ_SCRIPT_GUJARATI:
+    case MOZ_SCRIPT_GURMUKHI:
+    case MOZ_SCRIPT_KANNADA:
+    case MOZ_SCRIPT_MALAYALAM:
+    case MOZ_SCRIPT_ORIYA:
+    case MOZ_SCRIPT_SINHALA:
+    case MOZ_SCRIPT_TAMIL:
+    case MOZ_SCRIPT_TELUGU:
+    case MOZ_SCRIPT_KHMER:
+    case MOZ_SCRIPT_LAO:
+    case MOZ_SCRIPT_TIBETAN:
+    case MOZ_SCRIPT_NEW_TAI_LUE:
+    case MOZ_SCRIPT_TAI_LE:
+    case MOZ_SCRIPT_MYANMAR:
+    case MOZ_SCRIPT_PHAGS_PA:
+    case MOZ_SCRIPT_BATAK:
+    case MOZ_SCRIPT_BRAHMI:
+        return SHAPING_INDIC; // scripts that require Indic or other "special" shaping
+    }
+}
+
 void
 ClusterIterator::Next()
 {

intl/unicharutil/util/nsUnicodeProperties.h

@@ -119,6 +119,18 @@ uint32_t GetLowercase(uint32_t aCh);
 uint32_t GetTitlecaseForLower(uint32_t aCh); // maps LC to titlecase, UC unchanged
 uint32_t GetTitlecaseForAll(uint32_t aCh); // maps both UC and LC to titlecase
 
+enum ShapingType {
+  SHAPING_DEFAULT   = 0x0001,
+  SHAPING_ARABIC    = 0x0002,
+  SHAPING_HEBREW    = 0x0004,
+  SHAPING_HANGUL    = 0x0008,
+  SHAPING_MONGOLIAN = 0x0010,
+  SHAPING_INDIC     = 0x0020,
+  SHAPING_THAI      = 0x0040
+};
+
+int32_t ScriptShapingType(int32_t aScriptCode);
+
 // A simple iterator for a string of char16_t codepoints that advances
 // by Unicode grapheme clusters
 class ClusterIterator

layout/reftests/indic-shaping/reftest.list

@@ -1,22 +1,22 @@
-skip-if(B2G) HTTP(..) == devanagari-1a.html devanagari-1-ref.html
+skip-if(B2G) pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == devanagari-1a.html devanagari-1-ref.html
-HTTP(..) != devanagari-1b.html devanagari-1-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != devanagari-1b.html devanagari-1-ref.html
-HTTP(..) == devanagari-2.html devanagari-2-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == devanagari-2.html devanagari-2-ref.html
-HTTP(..) != devanagari-3a.html devanagari-3-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != devanagari-3a.html devanagari-3-ref.html
-HTTP(..) == devanagari-3b.html devanagari-3-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == devanagari-3b.html devanagari-3-ref.html
-HTTP(..) != devanagari-4.html devanagari-4-notref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != devanagari-4.html devanagari-4-notref.html
 
-HTTP(..) == gujarati-1a.html gujarati-1-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == gujarati-1a.html gujarati-1-ref.html
-HTTP(..) != gujarati-1b.html gujarati-1-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != gujarati-1b.html gujarati-1-ref.html
-HTTP(..) == gujarati-2.html gujarati-2-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == gujarati-2.html gujarati-2-ref.html
-HTTP(..) != gujarati-3a.html gujarati-3-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != gujarati-3a.html gujarati-3-ref.html
-skip-if(B2G) HTTP(..) == gujarati-3b.html gujarati-3-ref.html
+skip-if(B2G) pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == gujarati-3b.html gujarati-3-ref.html
-HTTP(..) != gujarati-4.html gujarati-4-notref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != gujarati-4.html gujarati-4-notref.html
 
-skip-if(B2G) HTTP(..) == bengali-1a.html bengali-1-ref.html
+skip-if(B2G) pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == bengali-1a.html bengali-1-ref.html
-HTTP(..) != bengali-1b.html bengali-1-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-1b.html bengali-1-ref.html
-HTTP(..) != bengali-2a.html bengali-2-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-2a.html bengali-2-ref.html
-HTTP(..) != bengali-2b.html bengali-2-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-2b.html bengali-2-ref.html
-skip-if(B2G) HTTP(..) == bengali-3a.html bengali-3-ref.html
+skip-if(B2G) pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) == bengali-3a.html bengali-3-ref.html
-HTTP(..) != bengali-3b.html bengali-3-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-3b.html bengali-3-ref.html
-HTTP(..) != bengali-3c.html bengali-3-ref.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-3c.html bengali-3-ref.html
-HTTP(..) != bengali-3c.html bengali-3b.html
+pref(gfx.font_rendering.harfbuzz.scripts,-1) HTTP(..) != bengali-3c.html bengali-3b.html

modules/libpref/src/init/all.js

@@ -435,6 +435,23 @@ pref("gfx.font_rendering.wordcache.maxentries", 10000);
 
 pref("gfx.font_rendering.graphite.enabled", true);
 
+// Check intl/unicharutil/util/nsUnicodeProperties.h for definitions of script bits
+// in the ShapingType enumeration
+// Currently-defined bits:
+//  SHAPING_DEFAULT   = 0x0001,
+//  SHAPING_ARABIC    = 0x0002,
+//  SHAPING_HEBREW    = 0x0004,
+//  SHAPING_HANGUL    = 0x0008,
+//  SHAPING_MONGOLIAN = 0x0010,
+//  SHAPING_INDIC     = 0x0020,
+//  SHAPING_THAI      = 0x0040
+// (see http://mxr.mozilla.org/mozilla-central/ident?i=ShapingType)
+// Scripts not listed are grouped in the default category.
+// Set the pref to 255 to have all text shaped via the harfbuzz backend.
+// Default setting:
+// We use harfbuzz for all scripts (except when using AAT fonts on OS X).
+pref("gfx.font_rendering.harfbuzz.scripts", 255);
+
 #ifdef XP_WIN
 pref("gfx.font_rendering.directwrite.enabled", false);
 pref("gfx.font_rendering.directwrite.use_gdi_table_loading", true);