Visualize car leaving track

[Henrik Heimbuerger]

The TrackWidget currently completely ignores the flag whether a car is still on the track. It should a) not draw a car when it's not on the track and b) visualize that somehow, like drawing it in a separate section.

[SVN]

New commit by hheimbuerger (revision [369]):
[Partial fix for ticket #102] Implemented simple visualisation for a car that has left the track.

Additionally, the flag isOnTrack of the CarPosition? is now actually used and probably needs to be checked in more situations in the future.

[SVN]

New commit by hheimbuerger (revision [413]):
[Partial fix for ticket #102] Implemented showing off-track cars semi-transparent.

Cars that have left the track are now shown semi-transparent (currently 30% opaque) at the position they left the track. This was implemented by adding another transformation to the MultiStyleImage, which also caches the transformation results.

The cars had to be converted because the MultiStyleImage expects 24- or 32-bit images, and they were 8-bit palette-based. While doing so, the old images have been moved into a subfolder and the main transparency of all images has been improved by hand.

[Henrik Heimbuerger]

Assigned for testing. (Sorry, someone had to take it. :) )

[Henrik Heimbuerger]

To do: visualise it in the thrust gauges, too.

[SVN]

New commit by hheimbuerger (revision [440]):
[Partial fix for ticket #102] The thrust gauge of a player now indicates that he has left the track.

Also changed the opacity of those cars from 30% to 50% because some cars on some tracks could hardly be seen after leaving the track.