Thunderstorm v1.1

- New Feature: Rain and its preferences
- Bug Fix: Camera speed pref
- Update: Background image is higher res
- Update: Lightning depth range further from camera

Yeah, kind of obvious in retrospect, but the initial release didn't have rain!  Well, it's here now, exercising the particle system I've been writing on and off over the last few weeks.  Some meaningful optimizations went into this one, as the system will now avoid updating fields that don't need to change, and can detect which ones to ignore fairly well.

The default rain effect simply plays overtop the camera - this is the least expensive one.  Fancier than that is rain that actually falls from where the clouds are, which is noticably more complicated as it means there's something like a dozen systems all updating at once.  Fancier still, you can enable both the global rain and the cloud-spawned rain all at once.  If you have framerate problems, I recommend sticking with the default 'everywhere' rain, though all of them behave fine on my HTC Incredible.

The depth range thing is a bit non-obvious... when a bolt of lightning strikes, it's placed randomly within the scene.  This includes depth, and previously it could get as close as 25 units from the camera.  This showed as noticeably low res sometimes, so now the close-range threshold is something like like 40.

Flowers v1.1

- New Feature: Particles in the wind
- Bug Fix: Camera Speed Pref

This is a fairly minor update that's partly a maintenance release, and partly to make use of a particle system I've been gradually getting working over the last few weeks.  The dandelion seeds blowing in the background are a simple particle effect making use of the new system, that I think help lend some additional motion to the scene.

The camera speed pref has been working incorrectly this whole time, a bug that apparently worked its way into a few other wallpapers as well.  I'll be fixing this as updates get made.

Thunderstorm Live Wallpaper v1.0

Update: YouTube video!
Update: Marketplace link!

This one actually went pretty quick, thanks to some artistic help from Joel Mejia and several hours trapped at an airport. :)

The most time consuming aspect of Thunderstorm was the clouds, which I guess is obvious in retrospect. The number of them needs to be minimized as these phones are very fill-rate limited, but at the same time you need several layers to get any kind of good motion.  I ended up defaulting to 9, spacing them out evenly along the Z plane (Z = up), and randomizing their depth between the camera and background layer.  The image distribution is random.

A lot of time went into tweaking the color ranges and nature of the alpha to allow them to blend together somewhat and create an amorphous shape when possible, as having sharp edges didn't play well in practice.  The phones I have access to also tend to knock the alpha channel to 4-bit (it looks like), which really hurts here.  It creates some pretty visible banding, so it was necessary to keep a fairly busy color channel to help hide that.  There's still a few artifacts here and there on a couple of the images, but for the most part the remaining banding isn't too bad.

To minimize fill-rate cost, both the lightning and clouds all have custom models that cut out the empty space so we're not rendering unnecessary invisible pixels... it's still a little expensive at times but it's about as minimal as is possible, I think.  The models themselves have normals forced outwards on the edges, so the clouds will directionally shade smoothly based on the light source in the scene.  The light direction very slowly orbits the periphery, but blips to the X origin of the lightning bolt when a bolt is spawned, then lerps back to its correct position.  The flash is accomplished by keeping the diffuse light as-is and spiking the specular light to the bolt's user-defined color, then fading that back down as the bolt fades out.

All this worked out pretty well.  There's still the occasional spot where the clouds kind of stand out as a cut-out sprite... that's really hard to eliminate completely without more layers of blending, but as updates happen I'll probably reduce it further.  As a whole the results here turned out really cool, and I'm happy to be able to release it.

I'm trying a different sort of approach to the free version with this one... the free version doesn't have an app icon, instead the settings button links to a pop-up dialog that explains the range of settings available in the full version, with a marketplace and web page link.  I'm hoping this is unobtrusive while still letting people know the full version's available if they want it.

Checklist

Things to get done on various projects:

* Sanity check app names for all wallpapers.
* Add Albania to EU Flags.
* Seahorse for Aquarium
* Popup menu when selecting fish for Aquarium
* Cleanup flare overlays for Thunderstorm clouds
* More prefs for Thunderstorm
* Confirm whether Motorola fixed their filtering bug with the 2.2 update They DID!

* Flowers update

European Flags Live Wallpaper v1.0

There's now an EU Flags Live Wallpaper to go along with the North American one!  This one features a collection of 8 picturesque backgrounds along with 33 national flags from throughout Europe.  As before, there's prefs for flag speed, camera speed, flag rendering style, and performance.  It's been localized into French, German, Italian, and Spanish as well.

We did make use of some Creative Commons Attribution images in this case.  There's a fantastic italian vineyard shot by Francesco Sgroi, a beautiful shot of the swiss alps by Problemkind, and a portion of a super-wide panorama shot by NathanMac87.  These all worked out great, and are much appreciated.

Check out the YouTube video!

NA Flags v1.05

 - Update: Sharper backgrounds
 - Update: Nicer preferences screen organization
 - New Feature: Puerto Rico and Greenland flags

Not a lot to be said on this one.  The background improvement is actually a bit of a bug fix -- originally landscape mode had more horizontal travel to the camera than it does now, and because of the width of the screen it was necessary for the background image to be wide enough to encompass the camera's full width.  At some point during development the landscape camera's motion got cinched up from a 90 degree arc to a 60 degree arc, but we never thought to fix the background model.  This means that about 25% of the background image was actually going to waste, because you couldn't ever see it!

So, the big change there cinching up the width of the background, so you can see more of the image now.  This has the happy side effect of getting a lot more pixels on-screen, and it's now visibly sharper.  On top of that, the canyon and mountains images were resaved with a higher compression quality, so they're outright sharper even without this change.  The sum total is a significant improvement in background quality.