Google and Adobe Contribute Open Source Rasterizer to FreeType

alancronin writes with this excerpt from a PC World article: "Users of Android, Chrome OS, Linux, and iOS devices may not realize it, but FreeType open source software is used to render fonts on more than a billion such devices. Not only that, but the FreeType project this week got a significant update from none other than Adobe and Google. Specifically, Google and Adobe on Wednesday released into beta the Adobe CFF engine, an advanced Compact Font Format (CFF) rasterizer that 'paves the way for FreeType-based platforms to provide users with richer and more beautiful reading experiences,' as Google put it in an online announcement on the Google Open Source Blog. The new rasterizer is now included in FreeType version 2.4.12. Though it's currently off by default, the technology is 'vastly superior' to the old CFF engine and will replace it in the next FreeType release, the project says." The article features examples of how the new engine improves font rendering; for more explanation of the CFF, see this blog post from Adobe.

Re:I hope it is not...

[Samantha Wright]

Adobe and Microsoft (and maybe Apple?) collectively own just about every font patent imaginable. In the late 80s, Adobe's PostScript licencing was sufficiently heinous that MS and Apple teamed up to circumvent it; that's how TrueType came to be.

Re:I wrote a CFF renderer in C#

[anss123]

In cff files there are commands that that describes the elements of a glyph. This is used to determine what is important when rendering fonts at small sizes. For instance you don't want the hole in the "A" character to disappear at smaller sizes.

True type files have small programs that you execute when rendering at small sizes that moves the points that makes up the glyph. CFF and Type1 has commands like "stemv" that describes a vertical stem, and then it's up to the renderer to best figure out what to do.

Type3 fonts have no hinting, and is often thought of as ugly for that reason, but with sufficient DPI they are just as good looking as any other type of font. They are a bit more annoying to render than Type 1 fonts, as they can contain color and even pattern fills, but AFAIK is not used much. My renderer can handle them too, except if they contain transparencies (AFAIK none do).

Re:Meh , fonts. Big deal.

[anss123]

The problem with bitmapped fonts were never that they look bad, but they are difficult to scale to different font sizes. Say, if you got a bitmapped font with the sizes for 8pt and 12pt embedded, but you need them at 9.5pt, then you're stuck with using a image scaling algorithm.

TrueType/CFF are based on vectors, and saying that we don't need vector based fonts is a bit like saying that we don't need SVG since we got PNG.

Re:I hope it is not...

[MrHanky]

One of the most significant patents (owned by Apple) expired just a few years ago [techrights.org]. I remember there was some code in XFree86 or Freetype or wherever that actually infringed on it, but the default build script commented it out. I also remember seeing a patch in one of the major Free Software GNU/Linux distros that happily circumvented it, resulting in quite decent font rendering. Of course, no one would suspect Debian of doing anything that would be good for desktops...

Re:Meh , fonts. Big deal.

[Dan East]

It's worse than that. You have 8pt and 12pt fonts embedded, but at what display DPI? The odds of being able to use the 8pt font bitmap at native 1:1 resolution and actually be the size an 8pt font should be is nearly zero.

Re:More Adobe Viral Distribution Software

[Psychotria]

The code was written by the freetype author, not Adobe or Google (i.e. they employed the freetype author for a little while to implement the changes they wanted into freetype).

Re:I wrote a CFF renderer in C#

[flargleblarg]

Well, no. Hints are metadata embedded in the font file which provide hints/clues to the rasterizer. The rasterizer then uses the hints to improve its own selective varying of the proportions. You can do selectively varying of proportions without hints. The hints just improve the process.

Finally, hinting is not the process of varying proportions. It's not even remotely that. Hinting is the process of adding hints to a font. A font designer takes a typeface and hints the font manually. Note that there are algorithms to assist with hint generation... hinting the hinting, if you will.