[aprssig] New icon images

Heikki Hannikainen hessu at hes.iki.fi
Fri Aug 22 02:05:54 EDT 2014

On Fri, 22 Aug 2014, SARTrack Admin wrote:

> I see that you actually rotate your icons... Its a nice idea, and when it 
> comes to an airplane icon, which is an arrow anyway, that looks logical.
> But when it is a car, you only only have to rotate it, but also flip it when 
> it goes in the oposite direction of the original drawing.

Right. My code flips the airplane too, just to reduce code complexity. :)

For the web site version, all rotations have been pregenerated during the 
software build process. It's a lot of little images, 19169 of them 
(number of symbols * overlays * rotations).

> And how do you deal with icons which realy should never rotate (house), but 
> the direction data may not be exactly zero (and this may happen). Do you have 
> additional data attached to an icon saying, 'never rotate'?

I have a map/dictionary/hash of symbols which can be rotated, and the 
original direction they're pointing at in the source image. I can publish 
that together with the symbols if it's useful.

     NSDictionary *initDirectionalSymbols = @{
                             @"/'": @0,
                             @"/(": @90,
                             @"/*": @90,
                             @"/<": @90,
                             @"/=": @90,
                             @"/>": @90,
                             @"/C": @90,
                             @"/F": @90,
                             @"/P": @90,
                             @"/S": @0,

Actually, here's the machine-readable CSV/JSON/XML/YAML -formatted symbol 
descriptions index which I published a couple months ago. I should put the 
degree values there, maybe. Bob's original list is a bit difficult to use 
in an application - whenever there are changes, they need to be manually 
merged in each application config. A machine-readable index might be 
helpful and easier to synchronize to apps.


   - Hessu

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