Description The GtkGammaCurve widget is a variant of GtkCurve specifically for editing gamma curves, which are used in graphics applications such as the Gimp. The GtkGammaCurve widget shows a curve which the user can edit with the mouse just like a GtkCurve widget. On the right of the curve it also displays 5 buttons, 3 of which change between the 3 curve modes (spline, linear and free), and the other 2 set the curve to a particular gamma value, or reset it to a straight line. As of GTK+ 2.20, GtkGammaCurve has been deprecated since it is too specialized.