Glossary

acceleration
Change in velocity over time. Used in incremental animation.

algorithm
A step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps. dictionary.com

ancestor
1. A tree data structure term that means some node in the succession of parent nodes on a path to the root. i.e., a node's parent and parent's parent are both ancestors of the node.

2. A reserved Lingo script property that can be used to establish inheritance.

animator function
In parametric animation, a function that uses the parameter to generate a value for a property.

biasing function
In parametric animation, a function used to 'ease-in' and 'ease-out' motion, or modify the speed in general. It is used between the driver and animator functions. It maps p:0->1 back onto p:0->1, is a curve, and satisfies p(0)=0 and p(1)=1. Its use takes the form p = bias(p).

class
An object-oriented term meaning the definition for a type of object. Classes are instantiated to create objects. In Lingo, each script is a class from which objects are instantiated using the new() method. See OO Fundamentals.

driver function
In parametric animation, a function used to transform a driver's value range to p:0->1. A driver is some element in the program that determines or affects the animation.

inheritance
An object-oriented mechanism whereby a class (script) can build on another class. In Lingo, the "ancestor" property is used to establish inheritance. See OO Fundamentals.

instance
An object is one instance of a class (script). Created by instantiation, and resides in memory as a working copy of the script. Any number of instances may be created from the same script, and each will have its own values for the properties (variables) defined in the script. In Director also known as a child object. See instantiation, reference, OO Fundamentals.

instantiate
To create an object from a class (script). In Lingo, this is done by calling a script's new() method (handler). Director instantiates scripts automatically if they are "attached" to sprites or placed in the frame script channel. See OO Fundamentals.

method
In Director, a method is called a 'handler'. It is a unit of code that may be called with arguments, execute, and may return a value. Methods are contained in classes (scripts). See OO Fundamentals.

object
Object-oriented programming term, synonymous with 'object instance' though it is sometimes used more abstractly. See instance, OO Fundamentals.

recursion
A programming technique in which a method calls itself. See Data Structures and Recursion.

reference
An object reference is a pointer to an object in memory, and is held in a variable. In Lingo the common way to get a reference to an object created from a script is to return it from the new() method with the statement return me. It is used to reference the properties and methods (handlers) of the object. This is done using 'dot syntax', objRef.property and objRef.method(). See OO Fundamentals.

render
To create a visual representation of a mathematical model. See Model/Display Separation.

scale
To multiply by a number, called the 'scalar'. Scaling a vector is done by scaling each of its coordinates.

traverse
To visit the nodes of a data structure by following node pointers. Usually done recursively. See Data Structures and Recursion.

vector
A vector is specified by a point, and indicates a direction and magnitude. It is drawn as an arrow from the origin (0,0) to its point. See Vectors.

velocity
Change in position over time. Used in incremental animation.