Back on the Map

Last time around I did some updates to libmikmod and the sdl-mixer library.  Considering my previous lack of testing on them, I decided it'd probably be best to be a wee bit more thorough this time.  So I tracked down some oldschool galaga style games and gave them a zipit makeover.  I'd really prefer to get a nice version of centipede, joust, or one of the many zelda clones on the zipit, but didn't see anything that struck me as easy, so space shooters was it this time.

I started with dodgin' diamond and all went well.  Even the two player mode seen above appears to work, although it's difficult to get 2 different hands on the zipit keyboard at the same time.   Next I decided to give the fancier looking powermanga game a try.  I thought I maybe powermanga would be a more challenging port, given the code size and some floating point bits, but it was pretty smooth right out of the box on the medium sound quality setting.  So I'll take that as a win and move on.

I still wanted to leverage my success with the fixed point supertux patch into something more substantial, so I decided to see if I could do anything with protracker.  I'd like a few more tracker options on the zipit, and my little piggy tracker port was stuck on a blank screen for some reason.  Meanwhile protracker looked almost feasible.  I did a quick and dirty screen hack to remove the pixel doubling and chopped last 15 rows of the display to fit it onto the zipit screen.  It actually looks fairly decent, but appears to require the fake mouse controls on the dpad buttons, and all sorts of internal mixer and filter code needs a conversion to fixed point if I ever want to hear more than an occasional squeek out of it.

Unfortunately, about halfway through the float to fixed point conversion, we hit the Christmas holiday season and the zipit irc channel came alive with chatter.  Someone mentioned the pspmaps location lookup appeared to be broken.  My attention deficit disorder took control and off I went into fixit mode.  It didn't take long to discover that google had shut off the V2 googlemaps API a while back.  The V3 options were JSON or XML.  No sign of the CSV and KML options from V2.  Oh well.  I'd been meaning to tinker with JSON again someday.  And now that day had arrived.  I checked out a few small JSON libraries for C, but I'd seen cJSON before in the opentyrian code, and it looked simple enough, so I went with that.  After a modicum of testing, I had a working fix for both the location and driving direction lookups, so I bumped the version number.

Someday I'd like to add an option to use the OpenStreetMap lookup as well.  That way there's a backup solution, just in case google decides to obsolete their API again.  Also, I suspect openstreetmap might make it easier to add support for more permanent offline map sets.

I noticed the original pspmaps site was gone, but there was a github project with a few odd fixes from just before the google API change.  So I forked it, got back up to speed with git (after maybe two years of rust), and rebased the openwrt-zipit pspmaps project off my github fork instead of the dead link to the past.  I still haven't restored my openwrt-zipit build system after the recent hard disk crash, so hopefully somebody will notice and rebuild the openwrt pspmaps package.

Here's the goodies:

dd2-iz2s.zip

powermanga-iz2s.zip

I still need to package up pspmaps.  For now here's a new executable and urls.txt file for pspmaps on openwrt.  Just untar it in the pspmaps directory.

pspmaps-update_2_4_wrt.tgz

Do the same for the iz2s executable.

pspmaps-update-2_4-iz2s.zip

I'll have to do another blog post if ever get one of those trackers working.

In the meantime I should probably say something about the Navit GPS/map program since it came up in the same IRC conversation as pspmaps.

By following the TomTom build recipe I got it to compile for iz2s, as a possible offline map alternative to pspmaps.  Apparently it wants to be in Germany?  However it crashed when I attempted to bring up the internal gui, so it clearly still needs some work...

Update:

Ok, I fixed the crash and found the maemo build recipe, which had some more clues on how to configure it better for the zipit, like converting the svg icons to png, and discouraging floating point math.

I still have a few more icons to track down and convert, but most of the menus look all right now.  Perhaps it's time to fetch some more map data, other than that sample patch in Germany.

So I visited the Navit Planet Extractor website and fetched me a rectangle of OpenStreetMap data.  The smallest chunk it wanted to give was around 80 megabytes, so I went with that.  It sorta worked.  I could search for towns and streets contained within the map data, but the map itself was a mess.  It was very slow to update and missing (or simply not displaying) features that I know should be there.  Perhaps the 32 megabytes of RAM on the zipit is not enough?  I've read some notes that suggest Navit is not the most efficient app in the world.  I'll have to play with it some more and see it there's any way to make it feel like a useful tool on the zipit.  Or maybe I'll just grab the 700MB prepackaged blob of north east corridor USA map data from the Planet Extractor and see if I can make the zipit pop...

Or maybe I should try to use something like gmapcatcher to fetch map tiles for pspmaps.  I might have to reorganize the pspmaps cache to be compatible with the directory structure though.  It looks like it might be close.

Update 2:

It actually was pretty close.  Well, not really.  The pspmaps cache is a simple list of N numbered png files.  The meaning of those files is stored in a separate disk.dat file as a list of x,y,z coordinates (and a number for the specific map service), one entry for each numbered file in the cache.   It's these entries that match the directory and file structure of the gmapcatcher data, exactly.  They also match up with the OpenStreetMap Slippy map tilenames convention.  That meant it required just a few new lines of code in tile.c to convince pspmaps to check the offline gmapcatcher data before resorting to a network lookup.

Here you can see where pspmaps used some offline tiles saved by gmapcatcher.  I used two different map servers so I could be sure.  On the bottom left is a tile fetched from google by pspmaps.  The rest of the image is made up of tiles pulled from the offline files saved by gmapcatcher.  I forget which map service it was using, but you can easily see the difference.

Anyhow, I'll eventually put some sort of Navit package for iz2s here, and another revision of pspmaps too.

Update 3:

I've run out of vacation time so I zipped up a Navit package for iz2s.

navit-iz2s.zip

I haven't yet tried any of the large pre-made data sets, so I don't really know if it's actually useful.  I'll get back to it eventually.

Meanwhile, I think pspmaps has a lot of untapped potential.  I put the code in my github repository and added my offline map code to work with the OSM_tile data from gmapcatcher.  I also fixed it to remember a preferred default map service, and tweaked the code to allow you to skip map services that don't interest you.  

I've got a few other small changes that I'd like to make.  The simplistic linear searching disk cache implementation could use some work to allow it to scale up.  Maybe hash table lookups, or at the very least least make it do a binary tree search.  I'd also like to add some simple versions of the gmapcatcher functions.  A small radius local area capture with a few autozoom levels would be nice.  And an OSM_tile format offline map export function would make it possible to use the zipit instead of gmapcatcher in a pinch.  And of course I still want OpenStreetMap location and driving directions lookup as an alternative to google.

Some wilder ideas include better driving directions, with access to the text version of the route, and maybe markers for the turns.  Point of Interest data might also be fun to play with.  Maybe OpenPOIs or the OpenStreetMap Overpass_API would work?  I could probably use some of the 16x16 png icons from Navit as the markers...

Hopefully I'll have something worthy of a release soon...

Ok, this has the offline stuff and allows you to comment out map services that you don't want in urls.txt.  See the readme.txt file for details.  Once again it's just an updated executable with urls.txt and a readme file, not a full package.

pspmaps-update-2_4-1-iz2s.zip

Same for the wrt update...

pspmaps-update-2_4_1-wrt.tgz

Update 4:

As life would have it, I actually got a chance to try out pspmaps in a real world situation. I had to visit a company near Boston to get me some nifty software training for work.  Christmas flew by and I still don't have a smart phone with a data plan, so I loaded up the offline cache in pspmaps on the zipit.  I also generated some driving directions.  It worked, but just barely.  The screen is just a wee bit small to see enough of the map while driving, the thin blue directions line was barely visible at night on the road, and I really could have used the text directions.

I can't do much about the screen size, so I widened the blue line in the code and got to work on parsing the text out of the JSON driving directions.

 Wider is better

I'm using the SDL_rtf sample app as a mockup for the display.  It works reasonably well for my purposes (and I still dream of a minimal word processor app on the zipit someday) so I think I might stick with it when I fold the code back into pspmaps.

While I'm at it, maybe I should try to hook up the flite speech synthesis from the bard package to read the text out loud.  At the very least I should try and feed this sample text to flite and see if the pronunciation is intelligible.  That should be an interesting exercise.

Update 5:

Ok, I haven't tried to hook up flite, but I did fold the SDL_rtf driving directions code back into pspmaps.  I really like the way it autowraps the text for me because I wasn't looking forward to writing that part myself.  I had a bit of confusion with latin1 text until I realized the rtf unicode escape sequence \uN is apparently not yet supported in sdl_rtf.  However testing reveals I can simply convert the directions to extended ASCII from the 8 bit latin1 codepage and use that, as seen here.  

 Better watch out for the speed cameras!

The last release of SDL_rtf is more than 10 years old, but it's had a few unreleased updates on the SDL mercurial repository.  I fetched the most recent update for SDL-1.2, from 2012, but didn't see anything that looked like unicode escape sequence support.  So for now I'm sticking with the SDL_rtf v0.1 code.  I added SDL_rtf to the list of openwrt-zipit packages but I don't have a compiler set up to build an actual package for it.  Because of that, I decided to static link SDL_rtf into some pspmaps executables.  

Here's another round of executable updates (and the urls.txt config files).

pspmaps-2_4_2-iz2s.zip

pspmaps-2_4_2-wrt.tgz

The Backspace key gets you to the text directions screen on the zipit.