Determines the general RTF font family a font belongs to based on its design. An RTF rendering application will use this information to find a font with similar appearance when an exact match cannot be found.

Supported values: roman, swiss, symbol, modern, script, decor, tech, bidi

This indicates the Windows codepage the font uses for its encoding.

Supported values: codepageAsInteger, -1, 10000, -1000, -1001, -1002, -1004

The special values have the following meaning:

Specifies the Unicode codepoint offset for this particular font. On platforms like Macintosh and Windows, fonts that have no Unicode mapping defined like Webdings or Hoefler Text Ornaments, will be mapped 1:1 into the PUA. Normally, this is the area of U+F000…U+F0FF, but by using the U-xxxx notation below, you can set the offset anywhere you require.

Supported values: normal | private | U-xxxx

with private being equivalent to U-F000, which is the Unicode codepoint offset (should be in the Private Use Area (PUA)) where this mapping starts, and normal being equivalent to U-0000, which is also the default if the property is not specified.

When downCast encounters a Unicode character to render to RTF, it first looks whether this character is part of the encoding of the current font. If it is, it is written according to RTF specifications. However, when this Unicode character is not part of the encoding of the current font, downCast tries to look up a font in the names specified using the @font-search-list option in order. The first one it finds will be used to write the character to RTF. However, for a subsequent RTF reader to pick this up correctly, downCast must write a switch of font for this specific character. This property specifies which method downCast should use for this, if possible:

When downCast needs to write a character, it can do it in two ways: either just the character for the current font's encoding, or additionally as the original Unicode codepoint. By specifying one of the following values for a font, you can tell downCast which method it should use )if possible):

downCast comes complete with virtually all default encodings you can use in RTF resp. Word, including many two-byte ones. This means that normally, you do not need to provide a custom encoding.

The default encodings are hard-coded with optimizations done for each specific encoding to provide efficient access, since the mapping functions are called for each character that passes through downCast. These default encodings are therefore not directly user-accessible. However, there are sometimes occasions where you'll need to use a custom encoding, especially when you are using custom fonts.

downCast provides a custom encoding loader and handler which lets you specify your own mappings from character codepoint in the font to Unicode by means of a simple text file. Both, one-byte and two-byte encodings can be specified in this way.

To create a custom encoding, you need to create an ASCII text file with the extension .encoding which specifies both the mapping of the individual codepoints to Unicode and also states which codepage it implements. You can also give it a name for easily spotting it in the UI portions of the application. downCast looks for custom encoding files in the {Encodings Folder} at startup. All encodings it finds are added to the internal set of default encodings. By specifying a codepage in a custom encoding that has a default equivalent, you may override any of the factory-supplied encodings.

Since the mapping is built on the fly, specific optimizations cannot be performed and the use of custom encodings may slow-down processing slightly.

A custom encoding per se is not tied to anything but the codepage it implements. To tie a codepage to a specific font, you need to extend or override the stdfonts.config file. In this mapping file, you simply list the font's name and associate it with a codepage using the keywords as described.

It is recommended to use codepage values greater than 40000 for custom encodings, as downCast will not use these codepages internally. Which you use for custom encodings is up to you. downCast reserves the range from 32000 to 35000 for internal use, so you should not use these. Also note that when you override a default encoding, every font that is specified to use that encoding will use the custom one.

File names can be arbitrary, must however have an extension of .encoding. They should be placed into the {Encodings Folder} for downCast to scan and load them automatically at startup.

The file structure is simple: one mapping entry per line, and all lines starting with #, // or ; are treated as comments. To create a two-byte encoding, separate the two bytes by a comma.

A mapping entry has the form (notation similar to BNF):

mapping ::= <srcbyte> [',' <srcbyte>] '=' <unicodechar>

with:

srcbyte ::= hexNumber | decimalNumber
unicodechar ::= hexNumber | decimalNumber
hexNumber ::= ('0x' | '0X' | '$')[0-9A-Fa-f]+
decimalNumber ::= [0-9]+

@codepage 42001
@encodingname Silly Encoding
$20=$40