Several standard zoom modes are provided for mouse interaction with 2D and 3D graphical displays. These are selectable via a call to
int tv_set_zoomlevel(Tv * tv, int zoomlevel)where the zoomlevel takes the following defined integer variables
IMZOOM == standard 2D image zoom ZOOMAF == constrained x and y zoom ZOOM2 == 2D image zoom including rotation ZOOM3 == 3D data zoom ZOOMGR == 3D surface viewerSelection of these alternatives determines how the 2D and 3D co-ordinate frames associated with each Tv are manipulated by mouse interactions. The best way to understand the capabilities of these options is to try them.