Inside Macintosh: 3D Graphics Programming With QuickDraw 3D /

Chapter 7 - Transform Objects / Transform Objects Reference

Data Structures

Rotate-About-Point Transform Data Structure

You can use a rotate-about-point transform data structure to specify a rotate transform about an axis at an arbitrary point in space (for example, when calling the Q3RotateAboutPointTransform_NewData function). The rotate-about-point transform data structure is defined by the TQ3RotateAboutPointTransformData data type.

typedef struct TQ3RotateAboutPointTransformData {
   TQ3Axis                    axis;
   float                      radians;
   TQ3Point3D                 about;
} TQ3RotateAboutPointTransformData;

Field Description

axis

The axis of rotation. You can use the constants kQ3AxisX, kQ3AxisY, and kQ3AxisZ to specify an axis.

radians

The number of radians to rotate around the axis of rotation.

about

The point at which the rotation is to occur.