Defined 3D Data Types

The following 3D data types are defined using the basic data types described in the previous section. These definitions are obviously convenient when giving the specifications below. But it's good to keep in mind that these types are not distinguished in the metafile format itself. For example, a three-dimensional point in a metafile is just three successive 32 bit quantities; the metafile contains no grouping device that would indicate that these 96 bits make up a point. Given the metafile itself, one may not be able to tell whether these are three Float32 , three Int32 , or three Uns32 . In a binary metafile, additionally, one would not be able to tell whether these are six Int16 , twelve Uns8 , etc. And in a text metafile, additionally, one may not be able to tell whether these are three Int16 or three Uns8 .

Also, Macintosh QuickDraw 3D does not have distinguished metafile types for the defined data types in this section. QD3DIO.h does contain routines to read and write many of them, but they takes as arguments the regular data types used in the core API--for example, TQ3Point2D .

Two-Dimensional Points

Three-Dimensional Points

Three-Dimensional Rational Points

Four-Dimensional Rational Points

Color Data Types

Two-Dimensional Vectors

Three-Dimensional Vectors

Parameterizations

Tangents

Matrices

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© 1997 Apple Computer, Inc.

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