Wednesday, November 30, 2011

Snowfall Live Wallpaper v2.06

  - Bug Fix: Pixelated aurora on some devices

We end up fixing this sort of thing here and there.  Generally, it has to do with a texture effect slowly losing its integrity over time, until eventually it just looks like a smear of color.  What's up with that?

Basically, 3D hardware operates at a fairly low level of accuracy.  So long as you keep your numbers small, everything is fine, but bigger numbers get more and more granular.  When you have a number like, say 1.0006 -- that goes down to one ten-thousandth.  At small values, the hardware maintains enough accuracy for that to hold up  just fine.  There might actually be ten-thousand increments between 1 and 2.

If you go bigger though, this stops being true.  If I had a value like 1000.0006 it might just get lopped off and be the same as 1000 is.  At high values it might only have a handful of fractions between whole numbers.  The higher you go, the less accurate the increments get.  Mostly this is okay when it comes to real-time 3D rendering.  A rough approximation is just fine.

So what does this have to do with pixelated aurora effects?  Well, the aurora effect in Snowfall consists of a few overlapping animated models, each of which has a shader on it that's built out of a few layers of textures.  One of these layers scrolls horizontally (the one mixing in the rainbow colors).  As it moves, the colors drift across the screen.

How much that layer has moved at any given frame is based on the amount of time elapsed.  This means if you've had the wallpaper running for a long time -- a few days perhaps -- that number is starting to get pretty big.  That means we're up into the thousands or tens of thousands, and all of a sudden when the hardware goes to render the texture it's starting to get all blocky.

It's easy to fix this sort of problem itself once you know where it is -- in this case using the modulous operator to make sure the value doesn't ever get very large.  The problem is that it's easy to miss doing that even when you know it might be an issue, and these sorts of bugs are easy to overlook since they take a long time to show up.   While we we make a point of testing every release, it may not have been left to run for hours and hours at any given time.

Anyway, long update for a short change list.  Hopefully that informs someone.  :)

Friday, November 25, 2011

NA Flags Live Wallpaper Fundraising for USO

I just wanted to mention that since our Child's Play donations went so well last year, we're hoping to do some of the same things this year!  First up, if you purchase the full version of NA Flags up through December 2nd, we'll be giving thirty cents per sale to the USO.  Help bring some cheer to the troops overseas!

Koi Live Wallpaper v1.3

  - New Feature: Floating flowers!
  - Update: Rearranged preference layout
  - Update: Misc framework improvements

The primary goal of this update is really to get the various framework improvements we've made over the last few weeks out there, as we've really helped stability in a few places.  Mostly these are all corner cases like if you really quickly cycle to the preview window and back a dozen times... but still, better than it was before.

I hate pushing updates with nothing new in the box though, so we've added a new slider to the prefs that allows you to add lotus flowers to the scene!  Hope everyone enjoys!

Thursday, November 17, 2011

Wavescape Live Wallpaper v1.01

  - Bug Fix: Rendering issue on Galaxy S2

The Galaxy S2's picky render target formats gets us again!  Sorry about that folks, the missing rays should be fixed now.

Snowfall Live Wallpaper v2.05

  - Update: New aurora effect!

Lots of folks wanted this improved, and now that this is running on 2.0 it's a lot easier to make it look good.  So, this update revises the aurora borealis effect in the sky, I think it's quite a bit prettier now!

Thursday, November 10, 2011

Snowfall Live Wallpaper v2.0

  - New Feature: Santa appearance frequency control
  - Update: Now using OpenGL 2.0
  - Update: Big speed boost on tablets
  - Update: Sharper, cleaner tree art
  - Update: Better stability

Spent a couple of days getting this product ported over to OpenGL 2.0, which should allow us to add more improvements over time.  The immediately visible change should be generally much snappier performance when using your home screen, and generally lower CPU usage.  In particular tablets now draw the background as only a single pass even when time of day is enabled, which is a big speed win.

In addition we've cleaned up the tree art to improve its sharpness and done a few other things like that.  As a result of the changes the aurora doesn't look quite the same, but I expect to improve it over the next update or two, as 2.0 gives us a lot more flexibility there.