Add sfntly library for font subsetting used in print preview.

third_party/sfntly/src/subsetter/font_subsetter.cc

Index: third_party/sfntly/src/subsetter/font_subsetter.cc
diff --git a/third_party/sfntly/src/subsetter/font_subsetter.cc b/third_party/sfntly/src/subsetter/font_subsetter.cc
new file mode 100755
index 0000000000000000000000000000000000000000..cd6b48460fc45f313046cc55b709a9dcd6ea3865
--- /dev/null
+++ b/third_party/sfntly/src/subsetter/font_subsetter.cc
@@ -0,0 +1,38 @@
+/*
+ * Copyright 2011 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "font_subsetter.h"
+#include "subsetter_impl.h"
+
+int subsetFont(const char* font_name,
+               const unsigned char* original_font,
+               const size_t font_size,
+               const unsigned int* glyph_ids,
+               const size_t glyph_count,
+               unsigned char** output_buffer) {

[brettw, 2011/07/19 05:09:42]

I actually wonder if this function is worth having. It seems like if any of
these checks are important, they should be in the impl. Isn't it easy enough for
callers to construct the object and call Load and Subset?

[arthurhsu, 2011/07/19 18:34:32]

The general idea is to shield the caller from inclusion of the whole sfntly tree
and its dependency, ICU.  Ideally we compile this font subsetting function as a
library and caller includes only font_subsetter.h.

+  if (output_buffer == NULL ||
+      original_font == NULL || font_size == 0 ||
+      glyph_ids == NULL || glyph_count == 0) {
+    return 0;
+  }
+
+  sfntly::SubsetterImpl subsetter;
+  if (!subsetter.loadFont(font_name, original_font, font_size)) {
+    return -1;  // load error or font not found
+  }
+
+  return subsetter.subsetFont(glyph_ids, glyph_count, output_buffer);
+}