Game Development Reference
In-Depth Information
Waypoints enable the player to plot a route for the unit and so exercise some con-
trol over how the units get to where they are going.
One of the most useful, and at the same time easiest to design, features you can
offer your player is to allow him to customize his input devices to suit himself.
Normally you handle this via a shell menu, although a few PC games store the
information in a text file that the player can edit. These are two of the most com-
monly offered customizations:
■
Swap left and right mouse buttons.
If the mouse has more than one button,
left-handed and right-handed players may need different layouts. Providing a mir-
ror image of your standard layout takes little trouble, so don't make players go
through a function-reassignment process just for this; give them a feature that
allows them to simply swap the current assignments.
■
Swap the up and down directions of the mouse or joystick in first-person 3D
games.
Some players like to push the mouse or joystick up to make their avatar
look up (an idea borrowed from screen-oriented steering in 2D games); others like
to pull it down to look up (an idea borrowed from airplane joysticks). Let the player
play as she prefers.
The term
degrees of freedom
refers to the number of possible dimensions that an
input device can move through. An ordinary key or button has one degree of
freedom: It can only move up and down. A joystick or mouse has two degrees
of freedom: It can move up and down, left and right. The Wii Remote has three
degrees of freedom. If two devices, both binary or both analog (see the discussion
in “Input Devices” earlier), have the same degree of freedom, you can generally
let the player interchange them, although there will be practical difficulties if one
device is self-centering and the other is not or if one allows unlimited travel and
the other does not. When exchanging assignments between two devices not identi-
cal in every way, some functionality or convenience is almost always lost.
Almost all games assign some of their player actions to particular keys or buttons.
Your game should include a
key reassignment
shell menu that allows players to
assign actions to the keys they prefer. If your game includes menus, also allow
the player to assign menu items to keys so he can select them quickly without
using the mouse. You may need to enforce some requirements: If the game requires
a particular action to be playable (for example, the fire-weapon action in a shooter
game), warn the player if he tries to exit the shell menu with the action still
unassigned.
