Pick Sequence

When picking information from the canvas, a single pick cannot always describe what the developer requires. Many instances require a standard and predictable sequence of picks to define some sensible interaction. A simple example of this is a line created between two points in space.

A more complex, but still a predefined sequence of picks, could involve different types of picks, for example, where a pick sequence requires a user to identify an item then pick a new position where that item is to be positioned.

In some instances, what could be perceived as being a simple single pick sequence can actually require several. The most obvious of these is a positioning picks, a simple position at the origin of an item is only one pick, but a position at an intersection could be either two or three picks depending on the items picked. In these cases, the numbers of picks are handled from within the edgPickType object.