Open type fonts extra glyphs and ligatures compatibility discussion

[Barbara B]

Hi Bill,

According to Wikipedia, the non-breaking space is "Windows (all applications) Alt+0160 or Alt+255 (on numeric keypad)" which, not surprisingly, shows up as empty on the keyboard layout you uploaded. Whether the character is actually generated by the OS, or by FontLab or the font pixies, I don't know.

The non-breaking hyphen is U+2011.

I've seen it said that the non-breaking hyphen can be accessed by Alt+2011 but that has never worked for me.

[angelize]

I am interested in hearing what you discover about why the extra features in that font (megolopolis extra) are not accessible.

Also if we are creating a font with ligatures would it be possible to have that as a TT font for use with X3D or would the ligatures have to be in an OT version only?

[Soquili]

Barbara the wiki article I found for non-breaking space http://en.wikipedia.org/wiki/Non-breaking_space states it only works in applications that support it's use. Back in the late 1970s, early 1980s this was better known as a hard space and was available in Word Star and most other word processors of that time. TeX, LaTeX, SGML, and HTML are plain text that also recognize the hard space.

Frances the number of ligatures depends on how many of the extra characters you want the font to support. Do we need † or ‡ for example. Is there a need for ¶ or § and how often to we use ¦ in our work? Are there many people that use « and » �in their designs?

As to why the extra characters in some OpenType fonts are not accessable in Xara Designer Pro it is a relatively new feature available in OpenType font creation and is not available in many applications. The programming required to create the feature within the font is not widely understood by font designers. In the reference book for font design I have the author states he does not understand the programming and usually copies the code from font to font. I am searching for more information about the OpenType features.

This link is supposed to be a simplified way of creating OpenType fonts: http://www.bergsland.org/2011/11/typ...ts-simplified/

[Barbara B]

Hi Bill.
If we can find out how to create the non-breaking space -- Xara Designer is one of the products that does recognize it.

I typed the following in Xara Designer Pro:

Xara Designer Pro Xara Designer Pro

The first Xara Designer Pro has Alt+255 (number pad numbers) between the three words that make up the name. The second one does not. If you resize the text box the first Xara Designer Pro acts like it is one word and the second will wrap between the words.

This post editor doesn't recognize non-breaking space when entered from the keyboard as Alt+255, so you can't see it working here, but when directly entered in Xara Designer non-breaking spaces do work!

[Soquili]

Barbara as long as an application recognized the non-breaking space we can include it within the font. We can copy the space and paste it into the correct cell for the hard space.

In the Ariel font Alt+0160 is the Non-Breaking Space.

[Barbara B]

Super!

Folks who do HTML coding should be useing the HTML entity   to produce the space, but anyone doing DTP in a program that recognizes it really benefits from having it in the font.

I commonly use non-breaking spaces to keep proper names, or dates together so that they are always on the same line and are read as a unit.

[adamtwar]

1. OpenType fonts come in two flavors: with TrueType outlines (.ttf extension, they are backwards compatible to TrueType fonts) and with PostScript outlines (.otf extension). Apart from the sort of outlines used to construct glyphs, these flavors are interchangeable and have the same abilities.

2. Any OpenType font can (but does not have to) include OpenType Layout features. OpenType Layout features are a mechanism to style your text with different glyphs than the default ones provided by the font. For each character (e.g. a letter), alternate glyphs can be included in the font. Those alternate glyphs can represent one character (e.g. a small-cap A or a swash A) or more characters (e.g. an fi or st ligature).

3. For many non-European scripts (such as Arabic or Indic), OpenType Layout features are applied automatically during typesetting, without the user's intervention. In that case, the alternate glyphs are necessary for correct orthographic rendering of that script.

4. For European scripts, some applications allow the user to selectively enable and disable features. Rather than inserting the alternate glyphs directly, the user would typically choose an appropriate feature, i.e. a styling function. There is a registered set of OpenType Layout features and each has a particular purpose, for example one is for replacing uppercase letters with small-cap letters, another for replacing lining (uppercase) figures with oldstyle (lowercase) figures, another for common ligatures, another for rare ligatures, yet another for swashes, others for so-called stylistic sets (which can be arbitrary decorative or special-purpose variants) and so on. Enabling a feature replaces the default glyphs with some alternate glyphs (depending on which feature is enabled), or repositions the glyphs (e.g. shifts them up or increases spacing).

5. OpenType Layout is not a proprietary technology. It is part of the international standard ISO/IEC 14496-22.

6. Many applications enable user-controlled OpenType Layout features, for example on Windows Microsoft Word 2010, Microsoft Publisher 2010, Microsoft PowerPoint 2010, Adobe InDesign, Adobe Illustrator, Adobe Photoshop, CorelDRAW Graphics Suite X6, Serif Page Plus X6, QuarkXPress 9, Microsoft Expression Blend, Adobe Flash, and quite a few others. On Mac OS X, all applications that use the system Fonts palette can use OpenType Layout features.

7. It's not completely trivial for software developers to add support for user-controlled OpenType Layout features, mostly because the developers need to add a user interface for the features, and they need to make changes to their application's text storage system so that the application "knows" which features have been enabled on which text. But "under the hood", adding support for them is not complicated. Windows includes a system library called Uniscribe which provides a programming API that allows developers to apply user-controlled OpenType Layout features to the text.

8. With the release of Corel DRAW Graphics Suite X6, the two most popular drawing applications for Windows (Adobe Illustrator and Corel DRAW) have support for user-controlled OpenType Layout features. Xara is clearly lagging behind. I'd encourage the Xara developers to consider adding comprehensive OpenType Layout support in the next generation of their software.

9. I'm an OpenType and font development expert and am potentially available for consulting services in that area.

Regards,
Adam Twardoch
http://www.twardoch.com/