Fonts in IDL Direct vs. Object Graphics

This volume deals almost exclusively with IDL Direct Graphics. However, the vector and TrueType font systems described here are also available in the IDL Object Graphics system, described in Using IDL.

IDL Direct Graphics

When generating characters for Direct Graphics plots, IDL uses the font system specified by the value of the system variable !P.FONT. The normal default for this variable is -1, which specifies that the built-in, vector-drawn (Hershey) fonts should be used. Setting !P.FONT equal to 1 specifies that TrueType fonts should be used. Setting !P.FONT equal to zero specifies that fonts supplied by the graphics device should be used.

The setting of the IDL system variable !P.FONT can be overridden for a single IDL Direct Graphics routine (AXIS, CONTOUR, PLOT, SHADE_SURF, SURFACE, or XYOUTS) by setting the FONT keyword equal to -1, 0, or 1.

Once a font system has been selected, an individual font can be chosen either via a formatting command embedded in a text string as described in Embedded Formatting Commands, or by setting the value of the SET_FONT keyword to the DEVICE routine (see SET_FONT).

IDL Object Graphics

IDL Object Graphics can use the vector and TrueType font systems. See Using IDL for more information on using fonts with Object Graphics. Any TrueType fonts you add to your IDL installation as described in About TrueType Fonts will also be available to the Object Graphics system.