Working With Images2

PtInDSequenceData

Tests to see if an image contains data at a a given point.



 
pascal OSErr PtInDSequenceData(

                     ImageSequence seqID, 

                     void *data, 

                     Size dataSize, 

                     Point where, 

                     Boolean *hit);

seqID: Contains the unique sequence identifier that was returned by the DecompressSequenceBegin function.
data: Pointer to compressed data in the format specified by the desc param.
dataSize: Size of the compressed data referred to by the data param.
where: A QuickDraw Point. 0,0 based at the top-left corner of the image.
hit: A pointer to a field to receive the Boolean indicating whether or not the image contained data at the specified point. The Boolean will be set to true if the point specified by the where parameter is contained within the compressed image data specified by the data param.

DISCUSSION

The PtInDSequenceData function allows the application to perform hit testing on compressed data. The hit parameter will be set to true if the compressed data contains data at the point specified by the where parameter. The hit parameter will be set to false if the specified point falls within a blank portion of the image.