Watchface: Heliocentric

Thanks for downloading Heliocentric.

Whether you're an astronomy buff or not, this watchface can provide a unique perspective on things. In the solar system view, for example, when the earth is at the 12 o'clock position relative to the sun, it is the winter solstice. As Earth proceeds counterclockwise around the sun, the other seasons begin at 9, 6, and 3 o'clock.

Any feedback is welcome.

Version History
1.6 - Fixed display refresh issue
1.51 - Compatibility update for latest firmware
1.5 - Improved initial start performance
1.4 - Support for Fenix3 and 920XT
1.3 - Added meteor animation
1.2 - Minor performance improvements
1.1 - Performance improvements, fixed possible drawing artifact while animating

Known Issues
Watch face does not fully redraw after notification icons appear on the watch face - workaround is to swipe left/right

Sforzando over 9 years ago

Hi there

Is there any chance you can adapt this for the epix?

Thanks

It may work, although I don't have a real device to test on. Would you be willing to beta test it if I posted a version for Epix?

Roger.Steel over 9 years ago

Yes - I would certainly be able to beta test. I would really appreciate your time if you choose to make a version available for the epix.

Sforzando over 9 years ago

Roger, I posted an Epix beta at https://drive.google.com/file/d/0Bw5WtrpNqKbPRVJ3QWs2Vjd3VVU/view?usp=sharing if you'd like to try it. I can't guarantee that it will work, but it seems ok on the simulator. Good luck!

Roger.Steel over 9 years ago

Sorry for the delayed response, I only saw it this morning. Thanks for your work making it available for the Epix. I got it running and it is fine until the minute changes. At this point, the "picture" section (the bit below the date) changes to white and shows a bit of my previous watch face and none of the earth, moon and planets. The picture of the earth then slowly rebuilds over about 5 minutes but there is nothing where the moon and planets are. Pressing the light button illuminates the screen but does not change it. If I press the down arrow button to go into a widget and then return to the watch page, it loads up correctly until the next minute change. Do you think that I may have an incorrect setting somewhere?
Thanks for all your work so far.

Sforzando over 9 years ago

Sorry, but I'm not sure what is different about the Epix. The version I sent to you uses literally the same code as the other devices, so I can only assume that something is different about the Epix firmware that makes it incompatible. Unfortunately it's tricky to debug without an actual device.

Former Member over 9 years ago

No longer working on the Fenix 3. Default watch shows instead. Shame.

Sforzando over 9 years ago

Please try again with the latest update. Firmware updates may have increased memory usage requirements of this watch face beyond the limits, but I think recent API updates Garmin may have reduced it again.

Former Member over 9 years ago

Hi!
Thank you for the nice app. Could you share the math? :)

Also, how do you start and end the animation? I've been trying to access the DrawingContext from the function that triggers when lifting your wrist, but I can't find out how to do it.

Best,
Boyan

Former Member over 9 years ago

By the way, I'm in the Pacific timezone but I see California disappear out of the mat at 2pm. Is it possible you fixed it for some other time zone?

Sforzando over 9 years ago

Math for Heliocentric

Boyant,

The watch face uses an inverse orthographic projection (see http://mathworld.wolfram.com/OrthographicProjection.html) to wrap a flat 2 bit-per-pixel map around the globe. The position of the sun is based on formulas at http://www.stargazing.net/kepler/sun.html and the planet positions are based on orbital elements from http://www.met.rdg.ac.uk/~ross/Astronomy/Planets.html. Due to CPU constraints I had to use some tricks like a square-root lookup table in order to make the drawing faster. I could have used a series of canned bitmaps but I didn't think that was as cool since I wanted to show the time and seasons accurately and would run out of memory.

The software should be agnostic to any particular time zone, but it's possible that the tip of California scrolls off a bit soon for some reason. It could just be the way the projection works around the edges on a limited resolution screen. At least from my vantage point, I've compared the watch face to the view of sun from earth at http://www.smeter.net/propagation/views/earth-from-sun.php and it seems to match up pretty well.

For the animation I'm simply using Ui.animate() on the X and Y positions of a bitmap in onExitSleep().

Glad you are enjoying the watch face.