This document discusses different types of computer graphics input devices. It divides input devices into logical and physical categories. Logical input devices are categorized based on the type of data they transmit and include locator devices that input coordinate positions, string devices that input text, and valuator devices that input scalar values. Common examples of each type are also provided.

1. 1
Computer Graphics
Input Devices

2. RM [2]-2
Input Devices
 Logical Input Devices
Categorized based on functional
characteristics.
Each device transmits a particular kind of
data.
The different types of data are called input
primitives.
 Physical Input Devices
Categorized based on the physical machine.

3. RM [2]-3
Logical Input Devices
 Locator Devices
Input Primitive: Coordinate position (x,y)
Examples: Mouse, Keyboard (Cursor-
Position Keys), Tablet(Digitizer), Trackballs,
Lightpens.
Applications: Interactive drawing and editing,
Graph digitizing.

4. RM [2]-4
Digitizer

5. RM [2]-5
Joystick and Trackball

6. RM [2]-6
Logical Input Devices
 String Devices
Input Primitive: A string of characters
Example: Keyboard
Applications: Text input

7. RM [2]-7
Logical Input Devices
 Valuator
Input primitive: Scalar values (typically
between 0 and 1).
Examples: Control Dials, Sensing devices,
Joysticks
Applications: Input of graphics parameters,
Graphics representation of analog values,
Process simulation, Games.