Panorama-Imaging Atom 5

Programming With QuickTime VR

Panorama-Imaging Atom

A panorama-imaging atom describes the default imaging characteristics for all the panoramic nodes in a scene. This atom overrides QuickTime VR's own defaults. Those defaults are described in "QTVRSetImagingProperty" in the chapter "QuickTime VR Manager."

The panorama-imaging atom has an atom type of kQTVRPanoImagingAtomType ('impn' ). Generally, there is one panorama-imaging atom for each imaging mode (see below), so the atom ID, while it must be unique for each atom, is ignored. QuickTime VR iterates through all the panorama-imaging atoms.

The structure of a panorama-imaging atom is defined by the VRPanoImagingAtom data type:



 
typedef struct VRPanoImagingAtom {

    UInt16                              majorVersion;

    UInt16                              minorVersion;

    UInt32                              imagingMode;

    UInt32                              imagingValidFlags;

    UInt32                              correction;

    UInt32                              quality;

    UInt32                              directDraw;

    UInt32                              imagingProperties[6];

    UInt32                              reserved1;

    UInt32                              reserved2;

} VRPanoImagingAtom, *VRPanoImagingAtomPtr;

majorVersion: The major version number of the file format.
minorVersion: The minor version number of the file format.
imagingMode: The imaging mode to which the default values apply. Only kQTVRStatic and kQTVRMotion are allowed here. See "Imaging Modes" in Chapter 2, "QuickTime VR Manager," for a description of the available imaging modes.
imagingValidFlags: A set of flags that indicate which imaging property fields in this structure are valid. See "Imaging Property Valid Flags" for a description.
correction: The default correction mode for panoramic nodes. This can be either kQTVRNoCorrection , kQTVRPartialCorrection , or kQTVRFullCorrection . See "Correction Modes" in Chapter 2, "QuickTime VR Manager," for a description.
quality: The default imaging quality for panoramic nodes. See "Quality Properties" in Chapter 2, "QuickTime VR Manager," for a description of the imaging qualities.
directDraw: The default direct-drawing property for panoramic nodes. This can be true or false . See "Imaging Property Types" in Chapter 2, "QuickTime VR Manager," for a description of the direct-drawing property values.
imagingProperties: Reserved for future panorama-imaging properties.
reserved1: Reserved. This field must be 0.
reserved2: Reserved. This field must be 0.

Imaging Property Valid Flags

The imagingValidFlags field in the panorama-imaging atom structure specifies which imaging property fields in that structure are valid. You can use these bit flags to specify a value for that field:



 
enum {

    kQTVRValidCorrection                        = 1 << 0,

    kQTVRValidQuality                           = 1 << 1,

    kQTVRValidDirectDraw                        = 1 << 2,

    kQTVRValidFirstExtraProperty                = 1 << 3

};

Constant descriptions

kQTVRValidCorrection: If this bit is set, the correction field holds a default correction mode.
kQTVRValidQuality: If this bit is set, the quality field holds a default imaging quality.
kQTVRValidDirectDraw: If this bit is set, the directDraw field holds a default direct-drawing property.
kQTVRValidFirstExtraProperty: If this bit is set, the first element in the array in the imagingProperties field holds a default imaging property.