Programming With QuickTime VR

Intercept Structure

When QuickTime VR calls an intercept procedure, it passes the procedure information about the intercepted function and the parameters for that function in an intercept record. An intercept record is defined by the QTVRInterceptRecord data type:



 
typedef UInt32              QTVRProcSelector;

struct QTVRInterceptRecord {

    SInt32                      reserved1;

    SInt32                      selector;

    SInt32                      reserved2;

    SInt32                      reserved3;



 
    SInt32                      paramCount;

    void *                      parameter[6];

};

typedef struct QTVRInterceptRecord QTVRInterceptRecord;

typedef QTVRInterceptRecord *QTVRInterceptPtr;

reserved1: Reserved for use by Apple Computer, Inc.
selector: A selector that indicates which QuickTime VR Manager function has been intercepted. See "Intercept Selectors" for a description of the available intercept selectors.
reserved2: Reserved for use by Apple Computer, Inc.
reserved3: Reserved for use by Apple Computer, Inc.
paramCount: The number of parameters contained in the array pointed to by the parameter field.
parameter: An array of the parameters for the QuickTime VR function specified by the selector field. The order of parameters in this array matches the order of the parameters passed to the specified function, except that the QuickTime VR instance parameter is not included in this array.

The QuickTime VR Manager internally stores all angle measurements in radians, and any angular parameters returned in the parameter field of an intercept structure are expressed in radians. In addition, a parameter of type float (for example, the panAngle parameter to the QTVRSetPanAngle function) is passed in the parameter field as a value of type *float .