PRIMER 22.1

"Polygonal Area" Mode

Picking works as follows:

Left mouse clicks are used to define a series of points that will form the vertices of a polygon. This can be any shape, with concave and crossed edges. It must have a minimum of three points and may contain up to 100 points.
Once it has, or will have, three points the polygon can be closed by any of the following methods:
- Clicking on (or very close to) the first point, to signify "close the polygon by joining last and first points".
- Double-clicking when selecting the next point, to signify "create this point and close polygon".
- Short cut key upper case " C " to signify "close the polygon by joining last and first points".
- Clicking on the [C] button on the top right (as in the image to the right here)
You can reject the most recent point by:
- A middle mouse click.
- Using the upper case " R " keyboard short cut.
- Clicking on the [R] button at the top right.
  
  Rejection of points can be repeated to delete successive points backwards towards the 1st until none remains.
You can reject the complete polygon and start afresh by:
- Using the " escape key " keyboard short cut.
- Clicking on the [X] button at the top right.
You can also use right mouse clicks to define the polygon, which work in exactly the same way as above except that when the polygon is closed you will be offered the same "right click options menu" of options you would get when using a right click for selection in the default "Pick + Rectangular drag" mode.