Overview

This chapter describes the components that perform tween operations, sometimes called tweeners. It also describes tween operations performed by QuickTime for tween types that are native to QuickTime.

A tween operation lets you algorithmically generate an output value for any point in a time interval. The input for a tween is a small number of values, often as few as one or two, from which a range of values can be derived. You can use output from a tween to modify tracks in a QuickTime movie, as described in Chapter 13, "Tween Media Handler." You can also use the output values in your application to perform other actions, unrelated to movies.

This chapter is divided into the following major sections:

• "About Tween Operations" introduces tweens and their uses and provides an overview of the tween operations that are possible.
• "Using Tween Components" describes how to create the tween containers that the tween media handler uses.
• "Creating a Tween Component" explains how to create a tween component for a new data type, interpolation algorithm, or both.
• "Tween Component and Native Tween Type Reference" describes the native tween types handled by QuickTime; the tween components included in QuickTime; and the constants, data types, and routines associated with tween components.