Game Development Reference
In-Depth Information
will simply stay on the current types of devices. Its growth has been so great since 2008, and its
reach so vast, that, for Android, it is clear that the sky's the limit.
Whatever the future brings, Android is here to stay!
Compatibility Across All Devices
After all of this discussion about phones, tablets, chipsets, peripherals, and so forth, it should be
obvious that supporting the Android device market is not unlike supporting a PC market. Screen
sizes range from a tiny 320 × 240 pixels all the way up to 1920 × 1080 (and potentially higher on
PC monitors!). On the lowest-end, first-gen device, you've got a paltry 500 MHz ARM5 CPU
and a very limited GPU without much memory. On the other end, you've got a high-bandwidth,
multicore 1-2 GHz CPU with a massively parallelized GPU and tons of memory. First-gen
handsets have an uncertain multitouch system that can't detect discrete touch points. New
tablets can support ten discrete touch points. Set-top boxes don't support any touching at all!
What's a developer to do?
First of all, there is some sanity in all of this. Android itself has a compatibility program that
dictates minimum specifications and ranges of values for various parts of an Android-compatible
device. If a device fails to meet the standards, it is not allowed to bundle the Google
Play app. Phew, that's a relief! The compatibility program is available at
http://source.android.com/compatibility/overview.html
.
The Android compatibility program is outlined in a document called the Compatibility Definition
Document (CDD), which is available on the compatibility program site. This document is updated
for each release of the Android platform, and hardware manufacturers must update and retest
their devices to stay compliant.
A few of the items that the CDD dictates as relevant to game developers are as follows:
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Minimum audio latency (varies)
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Minimum screen size (currently 2.5 inches)
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Minimum screen density (currently 100 dpi)
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Acceptable aspect ratios (currently 4:3 to 16:9)
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3D Graphics Acceleration (OpenGL ES 1.0 is required)
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Input devices
Even if you can't make sense of some of the items listed above, fear not. You'll get to take a
look at many of these topics in greater detail later in the topic. The takeaway from this list is that
there is a way to design a game so that it will work on the vast majority of Android devices. By
planning things such as the user interface and the general views in the game so that they work
on the different screen sizes and aspect ratios, and by understanding that you want not only
touch capability but also keyboard or additional input methods, you can successfully develop
a very compatible game. Different games call for different techniques to achieve good user
experiences on varying hardware, so unfortunately there is no silver bullet for solving these
issues. But, rest assured: with time and a little proper planning, you'll be able to get good results.
