All of these options are accessed by right clicking on an existing line. Vertex dragging is also enabled when clicking the edit icon in the left bar.
|the right click context menu|
The first option I want to cover is "Clone As". This allows you turn a line into a polygon, add a styled line that matches a polygon border, or simply backup an existing line before editing or resampling:
|right click -> Clone As -> Line. Done.|
Vertex dragging has been around for a while but it's worth a quick look. Right click - > Modify -> Drag Vertices.
At this point each vertex along the line or polygon gets a draggable white circle. Midpoints between vertices also get a partially transparent circle, which you can drag to create a new vertex. To delete a point, right click on it and choose Delete Vertex.
When you're done modifying the line, right click on it and chose Save Changes - or, if you made a mistake, Discard Changes.
Sometimes it's useful to break a line in two - say to delete a bunch of points at once, or to get around a GPS' limitation on the number of points per route. To do this, simply right click on a line at the point where you want it split, and choose Modify -> Split Here.
The opposite of splitting is joining. To join lines, one of the two must have a label. Right click on the unlabeled line and choose Modify -> Join Lines.
A dialog will come up asking what line you want to join with. If the two lines don't touch, CalTopo will automatically pick the best way to connect them.
Drawing a freehand line creates a lot of points. This can exceed the limits of your GPS, resulting in only getting part of a route. It also creates jitter, since no one has perfectly steady hands. You can work around these problems by resampling a line, reducing the total number of points.
You can shrink a line down to a fixed number of points, or to create points at a fixed interval like 500 feet. You can also optionally add a marker at each resampled point, in order to load them as waypoints onto a GPS.
Finally, you can reverse the order of a line so that directional styles will point in the opposite direction.