Initial commit of font compression code into public project.

2012-03-23 11:21:16 -07:00
commit dcecdd883a
49 changed files with 8454 additions and 0 deletions
@@ -0,0 +1,44 @@
+To build:
+
+Check out a recent version of OTS, so that ots-read-only/ is alongside cpp/
+
+Cd into cpp, and run "scons".
+
+Then, decompress a font using ./woff2-decompress font.wof2 > font.ttf .
+
+An example font is provided (Inconsolata-Regular.wof2). In this snapshot,
+it contains no actual compression, but does apply the glyf table transform
+and has the file format and structure as described in the current draft
+of the "WOFF Ultra Condensed file format" doc.
+
+That said, it is possible to get reliable estimates, and at the very least,
+bounds, on the compression efficiency, with the confidence that the
+compression is reversible. Running the compressor and doing a whole-file
+compression with a standard entropy coder such as gzip or lzma will yield
+a file size within a few dozen bytes or so of using a single entropy coded
+stream in the final file format.
+
+Another limitation of the current implementation snapshot is that it
+doesn't implement continue streams. These will follow shortly.
+
+= Building with lzma =
+
+The lzma-enabled build is made with gyp instead of scons. Right now, the build
+requires patching a clean copy of OTS. (And thanks to Bashi for the patch!)
+
+- Download GYP from http://code.google.com/p/gyp/
+- Download clean OTS sources:
+% svn checkout http://ots.googlecode.com/svn/trunk/ ots-read-only
+- Apply patch
+% cd ots-read-only; patch -p0 < ../ots-lzma.patch
+- Run gyp to generate Makefile
+% cd ../cpp; gyp --depth=. -f make woff2.gyp
+- Build
+% make
+
+Now run:
+
+out/Default/woff2-decompress Inconsolata-Regular-lzma.wof2 > i.ttf
+
+We expect the build recipes to be cleaned up before the code is ready for
+production, but this should be good enough for testing.