Friday, November 29, 2013

Apple MKMapView vs. Google iOS SDK map - CPU, compass image, center and rotate.

Why I didn't use native Apple's map a year ago when I was going through the options for my apps?

I was looking for the "live" map that would be able to follow your location, option to rotate so your heading can be always on top of the map and while it rotates it should rotate street names gracefully so they are not shown upside down.

Should I tell Apple maps for iOS6 failed miserably for all of those requirements. So I used Google's alternative. It gave me great rotation, street names handling and nothing to complain about.




Watching iOS7 location videos made me really intrigued, it looked like "oh, Apple fixed it all and brought us the map that can rotate correctly". I was really keen to try and after two months of fixing my apps for iOS7 and releasing them I finally got to try.... And I'm not sure this is it.

Why?

You basically have an option to either center the map yourself or set it up to track by itself:


[self.map setUserTrackingMode:[MKUserTrackingModeFollow|MKUserTrackingModeFollowWithHeading] animated:[true|false]

Well, there are few problems here. 

Rotate and center sync. If you want to rotate with one of the automated tracking options, you'd probably need to sync your rotation with the user location tracking animation. Otherwise, for my naive and short attempts the rotation and auto-tracking create weird effect of user location floating around its center. I didn't follow the path of trying to sync that yet and will see if this is worth an effort.

Compass image. Small extra annoying factor here is that once you rotate the map (set the map camera heading) to something not equal zero, the "compass" thingy appears in the right upper corner:



My first thought was - "oh, I'l move this thingy where I want or disable it for iPad version as I show heading elsewhere". Let me do a read up, let me google for it, let me study Apple's forum for it... What? I can't do it! I love Apple for things that were decided for us, it is part of their spirit and I'm glad they keep it even stronger now than before!

This compass thingy is not a big issue I can move my star button (that happened to be in this place by accident) - I'm not that picky.

It has glitches. From time to time it looks like map zoom is being reset for a moment and than re-established again. I can't really correlate it to whatever I'm doing (as I'm doing nothing but set camera's heading and I do for every location change while zoom "blink" only happens once in a longer while). And the first time I rotate it it goes through the field of black and white rectangular and then does it from time to time, probably when tiles has not been loaded yet for some area I suddenly need to expose by programmatic rotation. This never happens to the Google map.
+ When changing programmatically (or by setting the auto option with WithHeading) heading from 360 to 1, Apple's map rotates -360 + 1 degree. Like, this can't be true? I'm probably just silly. But Google does it right, and it makes me feel less silly and more desperate.
+ Compass image shows even when I have enableRotate to NO, but when phone points exactly to 0 heading, the compass image disappears. So when my user will drive exactly in North direction they know it by not seeing the image?! Very consistent!

I can center and rotate all by myself.

I'm a big boy, if I proved it with Google maps I can prove it everywhere?

Ok. I'm loosing that extra smooth animation for centering the map should I tell. But it just looks as it does for the Google maps, that would suffice. Seems to work just ok. So I was sitting and looking at that center and rotate I put together thinking "Stan, you are a genius, you proved it!".

As I tend to spend few minutes in this state, I felt how my lap is getting hotter, and hotter .... Oh oh, this is my beloved temperature based CPU profiling instrument! 

So here is the reason of why I'll be thinking twice now if I should use native Apple's map for the live map option, let me provide it here. On the top you'll see Apple's map consumption while centering and rotating and below it you'll see the same task executed by a Google map. If simulators doe this to my mac, I guess I can speculate the same CPU/battery consumption ratio will stay on real devices:


My story ends here, enough for this evening, I need to re-group, re-think, re-try, re-study ....








Post a Comment