Page 116 - DCAP303_MULTIMEDIA_SYSTEMS

Multimedia Systems

notes pointing Devices
A pointing device is any computer hardware component (specifically human interface device)
that allows a user to input spatial (i.e., continuous and multi-dimensional) data to a computer.
CAD systems and GUIs allow the user to control and provide data to the computer using physical
gestures—point, click and drag —typically by moving a hand-held mouse across the surface of
the physical desktop and activating switches on the mouse.

While the most common pointing device by far is the mouse, many more devices have been
developed. However, mouse is commonly used as a metaphor for devices that move the cursor.
A mouse is the standard tool for interacting with a GUI. All Macintosh computers require
a mouse; on PCs, mice are not required but recommended. Even though the Windows
environment accepts keyboard entry in lieu of mouse point-and-click actions, your multimedia
project should typically be designed with the mouse or touchscreen in mind. The buttons
the mouse provide additional user input, such as pointing and double-clicking to open a
document, or the click-and-drag operation, in which the mouse button is pressed and held
down to drag (move) an object, or to move to and select an item on a pull-down menu, or to
access context-sensitive help.
Examples of common pointing devices:

• Mouse
• Trackball
• Touchpad

• Spaceball—6 degrees-of-freedom controller
• Touchscreen
• Graphics tablets (or digitizing tablet) that use a stylus

• Light pen
• Light gun
• Eye tracking devices
• Steering wheel—can be thought of as a 1D pointing device

• Yoke (aircraft)
• Jog dial—another 1D pointing device

• Isotonic joysticks—where the user can freely change the position of the stick, with more or
less constant force joystick
• Analogue stick

• Isometric joysticks—where the user controls the stick by varying the amount of force they
push with, and the position of the stick remains more or less constant

• Pointing stick
• Discrete pointing devices
 directional pad—a very simple keyboard
 dance pad—used to point at gross locations in space with feet

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