Reference Sheet: Cross-platform Fonts

Jacqueline Landman Gay
HyperActive Software
Presented at RevConWest, June 2005

Much of the following information was gathered from the LiveCode mailing list, and is offered as a reference for cross-platform font issues.

The font issue

None of the major operating systems that LiveCode supports handle fonts in exactly the same way. Even though there are a few fonts that some systems have in common, the font metrics vary even between fonts of the same name. They will look and print differently on different platforms. Arial on Windows is not the same as Arial on Macintosh.

Windows by default displays fonts at 96 dots per inch resolution, and Macintosh displays them at 72 dots per inch. However, these default resolutions can (and usually do) change if the user has set their monitor to display at a different resolution. You cannot predict what the font metics will be on any given machine at any given time.

There is no easy way to resolve these conflicts that will enable your stacks to display identically on all platforms. The best solution is the simplest: allow the default system font to display in field text, or if you prefer more consistency, use a font common to all platforms. In all cases, leave some extra space in the field to allow for different word widths and line wrapping.

To set a field to always use the system default, set its textfont property to a font name that does not exist, such as “0”:

set the textfont of fld 1 to 0

Fonts common to all platforms

There aren’t many. Only Courier is supported across Linux, MacOS, Mac OS X, and Windows. Because it is a monospaced font, Courier isn’t very useful much of the time.

Below is a partial comparison table of some fonts shared across various operating systems. Users may install their own fonts at any time; this table lists only those fonts that are shipped with the operating system. If a font is not listed here, it is not relevant to cross-platform use. This table is not all-inclusive.

	Mac OS	Mac OS X	Windows	Linux
Courier	X	X	X	X
Helvetica	X	X		X
Lucida		X		X
LucidaTypewriter				X
Times	X	X		X
Arial		X	X
Arial Black		X	X
Times New Roman	X	X	X
Verdana	(often*)	X	X
Comic Sans	(often*)	X	X
Century Gothic		X	X
Copperplate Gothic		X	X
Impact		X	X
Lucida Handwriting		X	X
Tahoma		X	X
Times New Roman	(often*)	X	X
Trebuchet		X	X
Verdana	(often*)	X	X

* Not native to the OS but often auto-installed by web browsers or other software

User Recommendations

According to the mailing list, the most-recommended font for Mac/Windows deployment is Arial. Tahoma is also popular. For stacks that must display on Linux/Unix platforms as well, you will probably have to change the field text dynamically to a different font, or maintain separate versions of your stack.

Font metric comparisons

If you are determined to try for the closest appearance in cross-platform stacks, you can set the textfont and textsize of fields or stacks dynamically with scripts depending on the platform the stack is running on. Note that Windows fonts are not scalable, where Mac OS and Mac OS X fonts are. If you set a font size on Windows that does not exist natively, it will look bad. Macintosh fonts look good at any size, so it may be preferable to set your field text to a size supported by the Windows font, or else dynamically change the field fonts by script when the card opens. (LiveCode profiles can do this.)

Dar Scott posted the following helpful comparison table to the mailing list, This chart shows the formattedHeight and formattedWidth of the word "Washington" in different fonts and sizes on two platforms.

Mac OS X

textSize	textHeight	Arial	Helvetica	Courier	Courier New
8	10	10x40	9x40	9x50	10x50
9	12	12x48	12x48	12x50	12x50
10	13	13x55	13x54	13x60	13x60
11	14	14x57	13x57	13x70	14x70
12	16	16x65	14x65	14x70	16x70
13	17	17x68	16x68	16x80	17x80
14	18	18x75	17x75	17x80	18x80
15	20	20x77	18x77	18x90	20x90
16	21	21x85	20x85	20x100	21x100
17	22	22x88	21x88	21x100	22x100
18	24	24x95	22x95	22x110	24x110
19	25	25x103	24x103	24x110	25x110
20	26	26x105	25x105	25x120	26x120

Windows XP

textSize	textHeight	Arial	Helvetica	Courier	Courier New
8	10	9x39	----	13x80	8x50
9	12	10x40	-----	13x80	8x50
10	13	10x49	-----	13x80	10x50
11	14	12x55	-----	13x80	10x60
12	16	14x66	-----	13x80	14x70
13	17	14x66	-----	13x80	14x70
14	18	16x69	-----	16x90	14x80
15	20	17x78	-----	16x90	16x80
16	21	18x87	-----	16x90	17x100
17	22	18x87	-----	20x120	18x100
18	24	21x95	-----	20x120	20x110
19	25	24x102	------	20x120	21x130
20	26	24x111	------	20x120	22x130

So for Arial:

OSX	Windows XP
8	9
10	11 (except for height)
12	14 (except for width)

As you can see, even the fonts sizes that match superficially may not match exactly in all respects. You can come close, but it will not be identical.

Shipping fonts with your standalones

Some companies ship fonts with their applications so that they will more closely match across platforms. Bitstream makes a font called “Vera” that is specifically designed to display the same font metrics on both Windows and Macintosh. However, installing fonts into a user’s system is not always practical, and some users may not like it.

A last resort — images

An image of a block of text is always an option for static text such as labels. However, some people have resorted to using images of text characters, which are assigned to fields dynamically by script using the imagesource property. This requires careful preparation and meticulous scripting and unless an absolute match is strictly required, probably isn’t worth the trouble. Text editing such fields becomes almost impossible and scripts will no longer be able to use most of LiveCode’s built-in text chunking.

In conclusion

Our recommendation is: in most cases, pretty close is good enough.