Controlling and Scrolling - Learn SpriteBuilder for iOS Game Development - page 71

For instance, a background image that fills an iPad Retina screen (default 4x scale in
SpriteBuilder) must be at least 2048x1536 pixels, and 2272x1536 pixels is even better to
also cover the entire 4-inch iPhone screen when downscaled by factors 2 and 4. If your
app is designed only for iPhones (using 2x scale for all images in SpriteBuilder), a back-
ground image that fills the entire Retina screen must be 1136x640 pixels (568x320
points). But if you wanted to have the option to make an iPad version at a later time, you
should definitely design your images for the iPad Retina resolution, anyway.
Tip Though SpriteBuilder gives you full control over messing with the scale
settings, I say “mess” with a wee bit of resignation. You see, SpriteBuilder of-
fers a clear 1x, 2x, 4x scale for iPhone, iPhone Retina, iPad, and iPad Retina
devices that just makes it super-easy to develop for iOS. If you leave this path,
you're setting yourself up for a ton of extra coding and testing. Please don't go
there!
But let's face it, iPad Retina images are frickin' huge. They significantly in-
crease your bundle size, which you don't want, understandably. Instead, you
should experiment with the export formats and the Compress settings as seen in
Figure 2-25 in Chapter 2 . Even 16-bit color depth is still good quality for most
images, but it cuts down memory usage and file size by up to 50%. PVRTC
goes even further at the expense of image quality. And if that's not enough, read
the next section, “Project Settings,” for more options to reduce app size.
Now there's a third option as well, and that's using 2x resolution images for most, if not
all, game elements in a universal iPhone plus iPad app, and changing the scale type to UI
points for relevant nodes. This gives you an iPad version where the visible area of the
world is roughly twice as large as on iPhone devices, with the world seemingly zoomed
out (game objects appear smaller). Of course, your game design needs to respect that;it
needs to be fair and playable on both devices—specifically, considering unfair advantages
in multiplayer as well as greatly differing difficulty levels. Not many games use that ap-
proach, and for good reason—it can drastically alter the play experience between iPhone
and iPad versions.
Project Settings
If you're developing an iPhone-only app, SpriteBuilder gives you the option to change the
default scaling from 4x as well as to change which resources to publish. Open the File
Project Settings dialog, which is shown in Figure 3-9 .