Agfa AC3 Font Compression and Decompression

East Asian font files take up a large amount of memory. Font compression reduces the ROM and RAM impact of these files. Windows CE uses Agfa AC3 font compression. AC3 fonts are TrueType fonts in a compressed format. The following list shows some of the benefits of the AC3 technology.

  • AC3 technology works with any TrueType font.
  • AC3 technology is lossless; no glyph hinting data is lost during compression or decompression.
  • Calling the font does not decompress the whole font file but rather decompresses a limited range of characters.

Environment Variables

Platforms localized for East Asian locales use font compression by default. The following table shows how the SYSGEN_AGFA_FONT environment variable is used to control font compression.

Value Description
0 AC3 font files are not used.
1 AC3 font files are used.

Rendering Fonts

You can include both compressed (files with extensions such as .ac3) and non-compressed (files with extensions such as .ttf and .ttc) font files in your platform. If font compression is on, Windows CE will first look for the .ac3 file for the font and then use the non-compressed file if the .ac3 file is not found. If font compression is off, Windows CE will not use the .ac3 files.

 Last updated on Friday, October 08, 2004

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