[PDF] Fix font embedding restrictions.

src/core/SkTypeface.cpp

Index: src/core/SkTypeface.cpp
diff --git a/src/core/SkTypeface.cpp b/src/core/SkTypeface.cpp
index 09a64324af2ea25cfef458b059dc1b65ce865eb3..20b6c89e4641f6e4c9f7b761d92ec3c55dadf041 100644
--- a/src/core/SkTypeface.cpp
+++ b/src/core/SkTypeface.cpp
@@ -6,8 +6,10 @@
  */
 
 #include "SkAdvancedTypefaceMetrics.h"
+#include "SkEndian.h"
 #include "SkFontDescriptor.h"
 #include "SkFontHost.h"
+#include "SkOTTable_OS_2.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
 
@@ -259,7 +261,26 @@ SkAdvancedTypefaceMetrics* SkTypeface::getAdvancedTypefaceMetrics(
                                 SkAdvancedTypefaceMetrics::PerGlyphInfo info,
                                 const uint32_t* glyphIDs,
                                 uint32_t glyphIDsCount) const {
-    return this->onGetAdvancedTypefaceMetrics(info, glyphIDs, glyphIDsCount);
+    SkAdvancedTypefaceMetrics* result =
+            this->onGetAdvancedTypefaceMetrics(info, glyphIDs, glyphIDsCount);
+    if (result && result->fType == SkAdvancedTypefaceMetrics::kTrueType_Font) {

[bungeman-skia, 2013/12/09 18:32:59]

It seems you want to test for 'empty flags' here? Otherwise the extra code in
FreeType / GDI is going to just be recomputed here 99.99% of the time.

[vandebo (ex-Chrome), 2013/12/09 18:42:59]

Windows otm interface has a flag for not embeddable, but not for not
subsettable, so I can't just test for empty flags.  I considered removing the
per platform implementations, but I figured it would be safer to check for
licensing restrictions in all possible ways.  I could possibly by an argument
for removing the freetype implementation, but it doesn't seem like a lot of CPU
overhead.  What do you think?

[bungeman-skia, 2013/12/09 18:46:30]

We're already doing a ton of work, and just getting a pdf going isn't really all
that time sensitive, so it isn't a biggie.

+        struct SkOTTableOS2 os2table;
+        if (this->getTableData(SkEndian_SwapBE32(SkOTTableOS2::TAG), 0,
+                               sizeof(os2table), &os2table) > 0) {
+            if (os2table.version.v4.fsType.field.Restricted ||

[bungeman-skia, 2013/12/09 18:32:59]

It looks like all of the fields you're looking for here exist in v2. Any reason
to use v4? (Note that there is now a v5, I just haven't added it yet). Of
course, all of this works with any version, so it isn't a big deal.

[vandebo (ex-Chrome), 2013/12/09 18:42:59]

Sure, v2 is the first version with all the used flags defined.  Changed to that.
 Since they're not all in V0/VA I used the newest version.

+                    os2table.version.v4.fsType.field.Bitmap) {
+                result->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
+                        result->fFlags,
+                        SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag);
+            }
+            if (os2table.version.v4.fsType.field.NoSubsetting) {
+                result->fFlags = SkTBitOr<SkAdvancedTypefaceMetrics::FontFlags>(
+                        result->fFlags,
+                        SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag);
+            }
+        }
+    }
+    return result;
 }
 
 ///////////////////////////////////////////////////////////////////////////////