pioneerspacesim/pioneer — pull request #752 by johnbartholomew (2011-10-30 00:33:45+00:00)
Title: Add direction indicators at the edge of the view for target markers

This is done for #750, and includes pull request #751 (which was done for #108).

Some restructuring in WorldView to share code between the different indicators. There are five indicators:

* Velocity relative to frame (white)
* Nav target position (green square)
* Velocity relative to nav target (green)
* Combat target position (red)
* Combat target firing solution (red)

The combat target indicators are only shown in the front view (this should be fixed at some point to show on all views, with the firing solution shown only in views with an attached laser).

The combat target firing solution doesn't get an edge marker. All the others do.

There's a little bit of fiddling to try to avoid overlaying the combat target distance label with its speed label, but this isn't done comprehensively (other labels can overlap with each other or with the combat target labels).

The edge markers are the same colour as the relevant indicator; the nav target position edge marker gets a small square to differentiate it from the nav target velocity marker.