User Guide

FontLab 4
238
TrueType curves are 2
nd
-order curves (quadratic b-splines) that have one
control point, called the “off-curve” point:
C
ontrol
(
o
ff
-curve
)
point
End (on-curve) point
End (on-curve) point
Some TrueType curves may appear linked together and form a long
“supercurve” where intermediate on-curve points do not really exist, but
are implied by the rasterizer:
On-curve points
Implied on-curve points
Off-curve points
TrueType curves end with points that look exactly like vector points. Off-
curve points of the TrueType curves have a “plus” (in black-white mode)
or light-blue (in color mode) appearance.