3.3.5.9.2 Sending Slow-Path Pointer Update PDU

The structure and fields of the Slow-Path Pointer Update PDU are described in section 2.2.9.1.1.4, and the techniques described in section 3.3.5.1 demonstrate how to initialize the contents of the PDU.

The messageType field MUST be initialized with the identifier describing the type of the Pointer Update (see section 2.2.9.1.1.4 for a list of possible values), while the pointerAttributeData field MUST be initialized with the actual update data contained in one of the following structures:

When sending a Color or New Pointer Update, the server MUST save the pointer image in the Pointer Image Cache (section 3.3.1.9) and initialize the cacheIndex field with the index of the cache entry which was used. If the pointer image has to be changed and the image is already present in the cache the server SHOULD send the client a Cached Pointer Update to save bandwidth that would have been used to resend the image.

The contents of this PDU SHOULD be compressed by the server before any MAC signature is constructed and encryption methods applied if the size of the data payload exceeds 50 bytes. The Share Data Header MUST be initialized with the compression usage information (section 3.3.5.1).