User Guide

Hinting
517
How FontLab Previews TrueType Fonts
FontLab uses the real Windows TrueType rasterizer to give an exact preview of the TrueType hinting
for the Preview panel, the Pixels layer in the Glyph Window and the preview window in the Options
panel. To get a preview FontLab implements the following steps:
1. FontLab creates a very small TrueType font that includes the empty (notdef) character, current
character and all characters from the sample string of the Preview panel.
2. All characters in this font are mapped to codes starting from the 20h (32) - code of the space
character. The empty character is mapped to 0, as usual.
3. This font is exported in TrueType format using all the TrueType export settings, including
grayscale settings, maintaining the existing instructions setting and autohinting. A special font
name is set for this font to avoid conflict with any installed fonts.
4. This font is saved in the Windows TEMP directory with a name beginning with “~FL” and with a
TMP extension.
5. The new font is installed in the system.
6. All previews are made with this font. Previews in the Preview panel can use grayscale output if it
is available from the system and is allowed by the font.
7. When the font is no longer needed it is uninstalled and the font file is removed.
Like the Type 1 hinting preview panel, the TrueType hinting preview panel
can be opened and its options can be customized. Please refer to the
description of the Type 1 hinting preview panel on page 500 for more
information.