Text anti-aliasing and scalable fonts with Xft on X Windows

On X Window platforms Views can optionally use Xft and FreeType for font rendering.

Features:

  • Allows anti-aliasing and translucency (alpha channel) when drawing text.

  • Scalable fonts improve the rendering of transformed text in methods drawTransformedString(), and more specifically in the class IlvZoomableLabel.

  • Enabling and using this feature requires no addition or modification to the Views API. All the user has to do is use font names as returned by the 'fc-list' command. For example, if the 'fc-list' command output contains 'Liberation Serif:style=Bold', use the font description "%Liberation Serif-12-B" to load this font in Views.

  • The feature is optional. You can disable it by setting the environment variable 'ILVUSEXFT' or the resource 'UseXft' to false. By default, the feature is enabled if Xft is installed.

  • When the feature is enabled, Views first attempts to load fonts with Xft, based on their name or description. If this fails, Views loads the font using the Xlib; in this case, text rendered using this font does not have anti-aliasing or translucency.

Limitations:

  • Views does not ship Xft, so the functionality is only available when the target platform has Xft installed.

  • The feature can only be used in 'shared' format, i.e., when the application is linked with Views shared libraries. The functionality is disabled in 'static' format.

  • The feature is only available on Linux and Solaris platforms.