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Panorama sample atom ('pdat')

An atom that describes a single panorama.

Overview

A panorama sample atom has an atom type of kQTVRPanoSampleDataAtomType ('pdat'). It describes a single panorama, including track reference indexes of the scene and hot spot tracks and information about the default viewing angles and the source panoramic image.

The structure of a panorama sample atom is defined by the QTVRPanoSampleAtom data type:

typedef struct VRPanoSampleAtom {
    UInt16                              majorVersion;
    UInt16                              minorVersion;
    UInt32                              imageRefTrackIndex;
    UInt32                              hotSpotRefTrackIndex;
    Float32                             minPan;
    Float32                             maxPan;
    Float32                             minTilt;
    Float32                             maxTilt;
    Float32                             minFieldOfView;
    Float32                             maxFieldOfView;
    Float32                             defaultPan;
    Float32                             defaultTilt;
    Float32                             defaultFieldOfView;
    UInt32                              imageSizeX;
    UInt32                              imageSizeY;
    UInt16                              imageNumFramesX;
    UInt16                              imageNumFramesY;
    UInt32                              hotSpotSizeX;
    UInt32                              hotSpotSizeY;
    UInt16                              hotSpotNumFramesX;
    UInt16                              hotSpotNumFramesY;
    UInt32                              flags;
    OSType                              panoType;
    UInt32                              reserved2;
} VRPanoSampleAtom, *VRPanoSampleAtomPtr;

The minimum and maximum values in the panorama sample atom describe the physical limits of the panoramic image. QuickTime VR allows you to set further constraints on what portion of the image a user can see by calling the QTVRSetConstraints routine. You can also preset image constraints by adding constraint atoms to the panorama sample atom container. The three constraint atom types are kQTVRPanConstraintAtomType, kQTVRTiltConstraintAtomType, and kQTVRFOVConstraintAtomType. Each of these atom types share a common structure defined by the QTVRAngleRangeAtom data type:

typedef struct QTVRAngleRangeAtom {
    Float32                             minimumAngle;
    Float32                             maximumAngle;
} QTVRAngleRangeAtom, *QTVRAngleRangeAtomPtr;

Field descriptions

minimumAngle

The minimum angle in the range, in degrees.

maximumAngle

The maximum angle in the range, in degrees.

Topics

Data fields

See Also

Storing panorama tracks