QuickTime Vector Graphics

This chapter discusses QuickTime vectors. QuickTime vectors are mathematical descriptions of images that are smaller in size than their equivalent bitmaps and can be scaled without loss of image quality.

This chapter also provides background information about QuickDraw GX objects that you will need to know in order to use QuickTime vectors in your software. Note, however, that you do not need QuickDraw GX on your computer to use QuickTime vectors.

Read this chapter if you need to create and manipulate QuickTime vectors.

About QuickTime Vectors

Inside Macintosh: QuickTime Reference describes the basic characteristics of QuickTime vectors, how they are constructed using QuickTime atoms, and how they are related to QuickDraw GX.

QuickDraw GX Concepts and Structures

Inside Macintosh: QuickTime Reference describes the QuickDraw GX concepts and data structures that you need to understand in order to work with QuickTime vectors.

A QuickTime vector corresponds to a QuickDraw GX path object, which is one of the geometric shapes supported by QuickDraw GX. Path objects are closely related to, and are in some cases defined by, other QuickDraw GX geometric shapes, such as points and curves.

QuickTime Vector Data Streams

Inside Macintosh: QuickTime Reference describes QuickTime vector data streams. In QuickTime, paths and their characteristics are represented by a series of atoms in a QT atom container. This ordered series of atoms is called a vector data stream. A vector data stream contains atoms for paths, atoms that specify attributes of paths, and a final atom that marks the end of the data stream. This section gives detailed instructions for creating and manipulating these atoms.

QuickTime Vector Features Not Included in QuickDraw GX

Inside Macintosh: QuickTime Reference describes two features of QuickTime vectors that are not based on QuickDraw GX: gradient fills and minimum bit depth.

Using QuickTime Vectors

Inside Macintosh: QuickTime Reference explains how to create and manipulate QuickTime vectors. The examples use utility functions provided by the vector codec, described in "Vector Codec Component Functions", that eliminate the need to work directly with the QuickTime atoms in a vector data stream. If your software edits or parses a great deal of vector data, it may be more efficient to work directly with the atoms. For descriptions of the atoms in a vector data stream, see "Vector QT Atom Container".

Converting QuickDraw GX Data to QuickTime Vectors

Inside Macintosh: QuickTime Reference describes how to use the GX-to-vector transcoder included with QuickTime, which lets you convert QuickDraw GX data into equivalent QuickTime vectors. If your application already has QuickDraw GX data, or if you use a drawing program that can create QuickDraw GX data, the transcoder makes it easy to create vector graphics for your application

Constants

Inside Macintosh: QuickTime Reference describes the constants that are specific to QuickTime vectors.

Data Types

Inside Macintosh: QuickTime Referencedefines the data structures used by QuickTime vectors.

Vector Codec Component Functions

Inside Macintosh: QuickTime Reference defines the functions provided by vector codec components.

Vector Codec Macros

Inside Macintosh: QuickTime Reference describes a macro provided by vector components, which you can use to convert an integer to a Fixed value.