DeutschUsing Quivira
Quivira is free to use for any purpose, including commercial usage. You may also redistribute Quivira freely, but please do not alter it and do not claim it to be your own work. In case of redistributing Quivira, you do not need to provide an extra file with attribution, as this information is included in the TTF file itself. However, I would appreciate a link where reasonable.
There are some cases where Quivira might not be the best choice:
- Don’t use Quivira on websites. It’s not that I would not allow it, but you have to remember that most people do not have Quivira installed on their computers and thus their browsers will not use it, whether you tell them to do so or not. Currently, there is no well-functioning way to include a font in a website like you can include e.g. an image.
- Don’t use Quivira for complex scripts using combining marks, even if the characters are included in Quivira, without testing carefully. Sometimes combining sequences are rendered well, but generally they are not expected to work (see Combining characters).
- If you need to cover as many Unicode blocks as possible, you should use a more complete font or better a set of fonts. Code2000 is the most complete Unicode font available, and Everson Mono is a very beautiful monowidth font with a large set of characters. (But note that they are both not freeware!)
- Quivira might not be the best choice for every language. Different languages often have different typographical conventions. For example, Ļ is expected to look like an L with a cedilla (¸) in some languages, and like an L with a comma below in others. Quivira has only one version of each character, so you might prefer other fonts for some languages.
Your rendering program does not have to support Unicode in order to use Quivira, but in a non-Unicode environment you very probably won’t have access to all characters.
If you write a text using Quivira and send it to someone else, remember that he/she needs Quivira as well, especially if you use characters from the Private Use Area. You may include Quivira in a PDF, send the .ttf file or add a link to the download page.
SMP-Characters
The Universal Character Set (UCS) is divided into 17 planes, each with 65,536 codepoints. The first and most important one is the Basic Mulitilingual Plane (BMP, Plane 0) which is supported by every program that supports Unicode at all. However, a lot of programs do not support the other 16 planes.
Quivira contains some characters on the Supplemental Multilingual Plane (SMP, Plane 1), namely the ranges “Ancient Greek Numbers”, “Ancient Symbols”, “Lycian”, “Carian”, “Old Italic”, “Gothic”, “Lydian”, “Musical Symbols”, “Ancient Greek Musical Notation”, “Tai Xuan Jing Symbols”, “Mathematical Alphanumeric Symbols” and “Domino Tiles”. If they are displayed correctly, as a missing character or even as two missing characters each, depends on both the rendering program and your operating system.
For example, Mozilla Firefox 3, Microsoft Word 2002 and Adobe Reader 8 (tested under Microsoft Windows XP) all render them correctly. (Word does not show them in its symbol insertion dialogue, but if they are pasted in from another program, they behave just like any other characters.)
As a first test, look at this character: 𝔔
- If you see a fraktur capital Q, it is rendered correctly.
- If you see a single placeholder (usually a rectangle), your browser handles it correctly, but did not find a suitable font to display it. After installing Quivira and restarting your browser, it should work.
- If you see two placeholders, your browser does not support SMP-characters. They may still work in other programs, though.
Generally, it is hard to predict where these characters are displayed correctly and where they aren’t. You will have to test it yourself on your system.
Combining characters
Quivira contains some combining characters, especially in the block “Combining Diacritical Marks”. These characters are meant to combine with the characters preceding them, e.g. an A followed by a combining acute (´) should look like Á and not like A´. This means, they have to be aligned both horizontally and vertically, depending on the preceding character. There are a lot of examples, and they occur in many scripts, not only in Latin.
However, Quivira does not contain any instructions how to place them correctly. The horizontal alignment could theoretically be achieved by kerning (but is not, see Kerning), while vertical alignment is impossible in a TrueType font. Also, the horizontal alignment could never look perfect, because of characters like i and j, where the dot needs to be removed (which also is impossible in a TrueType font).
Some rendering programs are smart enough to render combining sequences (or some of them) correctly anyway. For example, Microsoft Word 2002 places the Hebrew diacritics perfectly, but not the Latin ones. Some programs may also replace known sequences by the corresponding precomposed characters, so it is possible that an A with acute looks alright, but an F with acute doesn’t (because the latter doesn’t exist precomposed).
In future, Quivira may be converted to the OpenType format, and then OpenType features might be included to solve these problems. (I already experimented with Rogier van Dalen’s OpenType compiler OTComp with great results, but unfortunately the SMP-characters got screwed up.)
Kerning
Kerning is the adjustment of the spacing between two characters dependent on their shapes. For example, in the sequence “Te” T and e are commonly moved nearer together than O and e in “Oe”, because due to their shapes the space between them looks bigger. Two characters with such an adjustment are called a kerning pair, and kerning pairs can be defined within a TrueType font, but there is a maximum of 10,000 kerning pairs per font.
Due to this limitation, Quivira is currently not kerned at all. While 10,000 kerning pairs seem to be pretty many, they are actually not even enough for the Latin script. If a Unicode font providing the complete Latin script has a kerning pair for T and e, it must also handle Ţ, Ť, Ŧ, Ƭ, Ʈ, Ț, Ⱦ, Ṫ, Ṭ, Ṯ and Ṱ followed by è, é, ê, ë, ē, ĕ, ė, ę, ě, ȅ, ȇ, ɇ, ɘ, ə, ɚ, ḕ, ḗ, ḙ, ḛ, ḝ, ẹ, ẻ, ẽ, ế, ề, ể, ễ or ệ. So this single example results in 12 × 29 = 348 kerning pairs. Now remember “Ta”, “To”, “Tu”, “Va”, “Ve”, “AV”, … and then there are more than 200 combining diacritics which would need adjustment on every letter. Now 10,000 does not seem so many any more, and even 100,000 would not suffice.
Furthermore, diacritics would also need vertical adjustment to look right, and this is entirely impossible in a TrueType font.
This problem may be solved in future versions by converting Quivira into an OpenType font, because the OpenType format provides better kerning mechanisms (characters can be grouped, so e.g. all kerning pairs consisting of a T-shaped character followed by any e-shaped character could be handled with a single rule, and there is no limitation on the number of rules). But as long as Quivira is provided as a TrueType font, there will be no kerning.
Hinting
Hinting is a technology inside the TrueType format used to adjust the glyphs in a font to the pixel grid of a computer screen. It is an assembler-like language, and hinting instructions have to be defined for every single glyph for every font size (for small font sizes). There are tools to do this automatically, but every result I could get so far was harder to read than the unhinted original font. Thus Quivira is not hinted.
Therefore, Quivira might look more blurred on the screen than other fonts. This does not affect printers, because printers have higher resolutions than screens and do not use hinting instructions anyway.
If and how much Quivira looks blurred, depends on your system and the rendering program. However, as Anti-aliasing, subpixel rendering and auto-hinting algorithms get more sophisticated and more widespread, the problem with missing manual hinting becomes less important over time.¹
Quivira already looks fairly readable in most rendering programs at usual font sizes, and I do not have the time to manually hint the thousands of characters. This means, hinting is not planned in the forseeable future, and Quivira will very probably never be hinted.
¹ If you use Microsoft Windows Vista, you shouldn’t see any difference at all. Vista uses Microsofts “ClearType” algorithm to smooth the glyphs, and the new Vista fonts like e.g. Calibri aren’t hinted either.
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