Peripherals supported by the 3DO Interactive Multiplayer system include:
Light gun
Extended joystick
Mouse
Control pad
Note: Examples for using the control pad are discussed in Getting User Input.
Peripheral devices are divided into two classes.
digital
analog
Digital
Digital peripheral devices are best suited for applications involving
on/off events with a limited range of motion. The control pad is a digital
device.
Analog
Analog peripheral devices are best suited for applications involving a
broad and continuous range of motion. The joystick, light gun, and mouse
are analog devices.
Analog peripheral devices work best with games that require smooth
control. It is possible to emulate the functionality of an analog device,
such as the joystick, with the digital control pad, but this ultimately
frustrates the user and is not recommended.
This document is concerned primarily with analog peripheral devices.
Personality
Each peripheral has a set of characteristics-a personality-that
makes it more suitable for some types of applications than for others.
Developers who take the time to understand the characteristics of the
various peripherals are in the best position to pick the appropriate
peripheral for their application, and to derive the maximum benefit from
the personality of that device.
The following list matches peripherals supported by the 3DO Interactive
Multiplayer system with games best suited to the personality of each:
Extended light gun-most often used with shooting games and arcade
games.
Joystick-the varying degrees of movement possible with this peripheral
ideally suit it for driving simulation and flight simulation games.
Mouse-best suited for games that require the player to click on items
on the screen, for example strategy-type games.
Noise Level
Relative noise level is another distinguishing characteristic of
peripherals. Noise level refers to the amount of superfluous information
traveling back and forth between peripheral and game. A noisy peripheral
is one that transfers a relatively large amount of irrelevant data. The
extended joystick, for example, continues to send information about minute
changes in its x and y coordinates even when idle.
The following is a comparative list of supported peripherals:
Light gun-moderately noisy
Extended joystick-noisy
Mouse-quiet
Filtering is a way of setting the resolution of a peripheral, that is, of
establishing a threshold at which information exchange between game and
peripheral becomes significant.
Based on the minimal movement perceived by the device, some type of
filtering is recommended to avoid jittering and expensive recomputations.
The 3DO:Examples:Eventbroker folder contains sample peripheral
filters.
The management of data transfer between peripheral and game is handled by
the event broker. See Event
broker for more information.